Blitz | FIA-18 | Specifications | Blitz FIA-18 Specifications

Andrew Duerden
Gordon Birtwistle
ISBN 0 9516102 0 1
2nd Edition
All rights reserved. No part of this book
may be reproduced or transmitted in any form
or by any means, electronic or mechanical,
including photocopying, recording or by
any information storage or retrieval system,
without permission in writing from the
copyright holder.
Front cover: Graham Turner
Produced by:
Martin Meadows Marketing.
Printed by:
J.T. McLaughlin Ltd., Euxton, Chorley.
Published by:
Euro Sport Publications,
Hadley House,
Great Glen,
Leicestershire. LE8 OGN
Ever since the basic Nova appeared on the
competition scene back in 1985, clubmen have
been recording success after success. In its first
year of rallying, the potent GM Dealer Sport
Nova GTE in the hands of Dave Metcalfe,
showed a fantastic turn of speed, emphasising its
competitiveness and serving notice of its
potential for honours.
That initial Nova GTE was put together by
Engineer Brian Ashwood and his team. Their
background work prepared the foundation for
the new Nova/Corsa project, the Motor Sport
Development engineers - David Gray, in
particular - developing and aquiring the many
and varied parts and components to produce the
"Clubmans" Kit. The kit, together with this
manual now ensures that anyone can faithfully
reproduce the factory specification, relying on
the techniques and experience gathered from
many years of successful competition and,
hopefully, gain the results that have now been
shown to be within the Nova/Corsa's capability.
This manual sets new standards in providing
an exact and detailed guide to the preparation of
a vehicle for motorsport use. Andrew Duerden,
together with Gordon Birtwistle, has tapped that
vast reservoir of specialist knowledge held by the
Motor Sport Developments engineering staff to
produce a unique reference book. The mystique
behind building a top-flight competition car has
now been removed - now its down to the driver.
Good Luck.
Melvyn Hodgson
Chairman and Managing Director
Motor Sport Developments
Every effort has been made to ensure that the
contents of this publication were accurate and
up-to-date at the time of going to press. No
liability can be accepted by the authors or
publishers for loss, damage or injury caused
by errors in, or omission from, the information
Motor sport can be hazardous and the inclusion of any information does not necessarily
make it safe to use in any form of competition
or testing.
The modifications described in this publication are, in some cases, of an extensive nature
but have all been specifically designed to give
the ultimate performance. These may adversely
affect the normal life of standard parts and
may thus affect the New Vehicle Warranty.
This does not mean that the performance car
will be unreliable - in fact, it may be assumed
that it will be at least as reliable as other cars of
comparable performance.
Any inclusion of performance parts in the
Clubmans Kit or parts described in this booklet
does not necessarily mean that the parts comply
with the relevant homologation regulations or
National Type Approval requirements. It is the
competitors responsibility to ensure that his
vehicle complies with regulations and is eligible
for the specific homologation category for which
the vehicle is entered.
I ntroduction
Model Availability
- Bodyshell
- Front suspension
- Power Steering
- Rear suspension
- The Braking system
- Engine
- Transmission
- Electrical
Group N guidelines
- Clubmans Kit contents
- Homologation papers
This manual has been specifically produced in
conjunction with the GM Euro Sport package of
parts assemblies and components produced by
Motor Sport Developments and known as the
"Clubmans Kits". Consequently, the text refers
exclusively to the preparation of a Nova/Corsa
model to FIA International Group A level to the
specification within the Clubmans Kit. Other
parts and assemblies can be used in preparation
of a group A Nova/Corsa, but they are not
included in this manual and do not form part of
the GM Euro Sport package.
The manual has been laid out with easy-toread pages within well - defined sections. The
preparation chapter has been sub-divided into
various sections referring to vehicle sections bodyshell, running gear, etc - this has then been
subdivided into the separate divisions relating to
specific components. At the end of each section,
you will find a parts diagram together with a list
of parts and assemblies referred to within that
section. The actual pricing list is in a separate
booklet supplied with this manual.
Now you have received the manual, it is of
paramount importance that the registration card
at the front is completed and returned. This card
is the only method by which to ensure further
updates for the 12 month period following
registration will be sent to you. As new
equipment is developed or a component is
evoluted, bulletins to update the manual will
automatically be sent to those who have
registered on the cards provided.
This manual is designed to provide you with
the fullest information on the preparation of a
Nova/Corsa model for international rallying.
We are always interested to know your
comments in writing on any aspect that you feel
could be improved or modified. We will also be
happy to receive any details of ommisions or
items that you would like to see in the manual.
Only by feedback can we continue to improve on
what is hoped will be a helpful and informative
When preparing a vehicle to the clubmans
specification contained in this manual, it is
i ntended that the base vehicle used will be an
existing Nova GTE or Corsa GSi. These models
are identical save for badging and very small
differences in trim. Additionally, some slight
variations on standard specification occurs,
territory to territory. For instance, most Nova
GTE models sold in the U.K. come equipped
with central locking and sunroofs. Corsa GSi
models sold in right hand drive form in the
Republic of Ireland do not have these two items
fitted as standard. However, apart from these
minor differences, the main mechanical
characteristics remain the same.
The motive unit is a "Family One", nominal
1600 cc, overhead camshaft, fuel injected type
which is designated 1600 SE and, currently, is
not fitted to any other vehicle. The `Family One'
group of engines (which includes the 1200 cc and
1300 cc version with different bore/stroke
configurations) also includes a carburettored
1600 cc unit (known as 1600 SV type) which has
a different cylinder head and distributor to the
SE motor, but in most other respects remains the
The transmission is known as the F13 type
and the basic production unit is fitted, in five
speed form, to all GM 1600 cc Family One
engined Vauxhall and Opel cars.
The 1600cc injected Nova and Corsa
GTE/GSi models were first introduced in the
spring of 1988 and received no major revisions
to the standard specification until late 1990
when a facelifted version was introduced. This
model incorporated revised bumpers, grille, front
wings and headlamps coupled with a new
interior styling package, and was referred to as a
GSi in both Nova and Corsa livery.
Although this manual concentrates on the
preparation of vehicle using a Nova/Corsa
GTE/GSi as a base, the section concerning
bodyshell preparation does include details on the
minor differences in bodyshells, if preparing a car
from another hatchback bodyshell from the
range of various cubic capacity Nova/Corsa
Vauxhall Nova GSi
The Vauxhall Dealer Sport Nova in Scrutineering
The use of production series cars in international
motorsport is governed by a set of rules and
regulations laid down in the annual `Year Book
of Automobile Sport' issued by the FIA (the
governing body) and specific vehicles require
documents to verify their approval for use, and
these are issued by the International Motor Sport
Federation (FISA) as the Sporting Ministry of the
FIA, and are contained in Homologation Papers.
The 1.6 injected Nova and Corsa models are
contained in one document covering both
badged variants. The relevant document has
been issued with the FISA Number A-5375 and
is obtainable from the ASN or National Sporting
Authority of the country ir. which you are based.
At all events in which a car is entered within the
group A classification, the vehicle must have the
FISA Homologation Papers. The responsibility
of obtaining these papers from the ASN is that of
the entrant and/or driver.
As a guide, a set of specimen homologation
papers for the Nova GTE/Corsa GSi are included
in this manual. These papers CANNOT be used
as homologation documents at event
From the specimen set, you will see that the
first 16 pages refer to the basic specification of
the production vehicle. The following pages then
refer to specific items used in motorsport and
unless the item is included within these pages, it
cannot be used on a vehicle prepared for group A
classification. You will find that the "extension"
papers (i.e. those pages after the first 16 basic
sheets) refer to a number of the same items but to
different specification or dimensions. For the
purpose of the Clubmans Kit, all items are
homologated and are recommended fitment,
even if there are other similar items
homologated. It is the case that although, say, a
number of brake disc/caliper combinations have
been homologated and tried on the Nova/Corsa
models, the actual unit used in the clubmans kit,
and referred to in the text, has been found to the
best alternative and has been developed specially
for the Clubmans Kit package. Therefore it is
the only unit that should be fitted.
Although this manual is not primarily concerned
with group N preparation, you will find that at
the end of the specimen homologation sheets,
there are a number pertaining to group N. These
are additional sheets which are only required
when entering the group N category, and are
additional to the group A sheets. Thus a group
N entrant must have both the `A' and `N'
sections of the homologation documents when
submitting a vehicle for event scrutiny.
This manual should provide all the information
and detail required to build a car to group A
specification. The full details of what exactly is
permitted in both the `A' and `N' categories is
published in the FIA Yearbook, available from
bookshops or direct from:-
Editions V.M.
116, bd Malesherbes
75017 PARIS
Tel: (1)
Fax: (1)
The Bodyshell preparation and strengthening
procedures outlined in this manual are
fundamental to the success of the finished
project. They will both extend the competition
life of the shell and by increasing its torsional
stiffness contribute favourably towards the
handling characteristics of the finished vehicle.
FIA Regulations, Appendix "J" for Touring cars,
Group A permit a limited amount of bodyshell
reinforcement, but it is important to adhere
strictly to the definitions of the particular Article
No. 5.7:1 Lightening and Reinforcements. All
modifications outlined within this chapter are in
compliance with these guidelines.
General Motors Europe have extensive
motorsport experience with the Nova/Corsa
model and have developed a body strengthening
kit specifically for use in conjunction with the
1600cc. model range. This kit includes all the
additional reinforcement plates required for the
suspension pick-up points, engine mounting
points, roll cage pick-up points and a side jacking
point, etc. When fitted in conjunction with the
requisite additional welding as described, will
give an adequate degree of increased strength
and durability demanded by a motorsport
A specially designed roll cage has been
developed and homologated for this model. This
cage also incorporates the rear mounting points
for the safety harnesses.
Due to the nature of the modifications, they
can only be effectively carried out on a bare
bodyshell, so if your starting point is either a new
1600 Nova GTE or Opel Corsa GSi, then all
mechanical, trim and electrical components must
be completely removed from the vehicle before
embarking on any aspects of bodyshell
preparation. Whilst this section applies primarily
to bodyshells with Part Number 90297213
LHD, or 90297215 RHD, bodyshells from other
sources can be used, although they may differ in
several basic respects. The main differences
being confined to the front suspension turrets
and the inner and outer chassis rails. They have
already been additionally strengthened in the
1600 models. From experience these bodyshells
do not present any problems under motorsport
conditions, and are equally as good as the 1600
shell when fully prepared with the body
strengthening kit. Obviously some additional
plating and welding could be required
particularly in these areas on bodyshells from an
alternative source.
Before commencing any bodyshell
preparation operations, both front wings, doors
and tailgate must be removed from the
bodyshell. All sound deadening material and
general sealants around all body seams can then
be removed to provide more favourable welding
conditions. The application of heat to the
required area will enable any surplus material to
be scraped off more readily, finishing off the
operation with a wire brush. It's a fairly
laborious task but very important and if
thoroughly carried out will pay dividends at the
welding and later stages of preparation.
Any surplus brackets, unused supports such
as brakepipe/petrol pipe clip attachment points
can be removed, and to enable a revised seat
mounting system to be fitted, the standard seat
adjustment/mounting brackets should also be
removed with care. This will enable a much
more satisfactory installation of a wide range of
competition type seating for both driver and codriver. Also carefully remove both the gearlever
gaiter support bracket and the centre support
shelf from the centre tunnel section, in readiness
for the installation of the revised gearshift and
linkage at a later stage. Once the carpet centre
support has been removed, an elongated hole,
approximately 80mm by 25mm must be formed
in the centre section of the floor panel, along its
centreline, starting 80mm rearward of the tunnel
to bulkhead bodyseam. This is to give access to
the engine bay for the revised gear linkage. The
area of centre tunnel and exposed hole
i mmediately below the gearlever gaiter support
bracket can be closed off and strengthened using
the shaped blanking plate supplied. This should
be welded into place.
The gear-linkage forward support bearing
housing bracket should be welded into position
at the forward end of the centre tunnel.
Access for this operation is from the
underbonnet and underside of the bodyshell.
However, before welding this bracket into place,
the bearing housing itself should be modified to
fit the bracket correctly. This will entail cutting
away a portion of the bearing housing flange just
below two of the attachment holes. Three holes
should then be drilled through the housing and
bracket, using the housing as a template. Three
nuts should then be tack welded to the rear face
of the bracket. This will enable easy attachment
of the bearing housing to the bracket after it has
been welded into position.
This bracket is shaped to fit the exact
position required, and when measured should be
65mm rearwards from the face of the steering
rack mounting plate. This should then exactly
locate the bracket in its correct position, which
when measured should be 65mm rearwards from
the face of the steering rack mounting plate.
NOTE: This is a delicate operation as the
positioning of this support bracket is crucial for
satisfactory gear linkage operation.
The aperture in the steering rack mounting
bracket where it meets the lower chassis region
must also be increased in size along the lower
edge by removing 10mm from this flange. Seam
weld the section after removing this metal.
NOTE: This MUST be carried out at this stage
to give adequate clearance for the revised
gearchange mechanism.
Refer to the diagrams for guidance.
The bodyshell, now free from all unwanted
items, can be cleaned off in readiness for the
seam welding and strengthening operation. All
exposed body seams throughout the bodyshell
that are actually spotwelded in the production
process require further "stitching", preferably
with a MIG-type welder. This entails making an
additional 25mm run of weld every 35mm along
EACH visible body seam throughout the
bodyshell, and applies equally to the underside,
underbonnet and bulkhead areas. However, the
lower flanges of the front chassis rails where they
j oin the inner wheelarch require special attention.
Using either a spotweld cutting tool or drill bit,
carefully cut through ONE THICKNESS of the
seam in between each production spotweld and
fill hole with weld, forming a "puddle weld". In
addition to this operation, certain areas require
further reinforcement by welding on additional,
specially profiled mild steel plates. These are
supplied in the kit, their profile following that of
the original area and by double skinning give the
additional strength required. Final positioning
will be apparent when the plates are placed
against the designated area, and should not
require further modification prior to welding in
place. The inner pivot point for the bottom
wishbone can be further strengthened by welding
a large metal washer onto the forward face. The
hole through the pivot should then be opened
out to 12mm, to accommodate the larger
diameter bolt. The bodyshell also has in excess
of 20 drain holes in the floorpan, these must be
closed off by welding the circular discs supplied
over the holes. The side lift jacking point can
now be fitted. Place the strengthening plate
against the sill and mark the centre of the hole
required. This should be 22.5cm rear of the
front wing joint on the sill. Cut a 35mm. hole
through outer skin only. The inner 35mm. hole
should be formed with its centre 55mm. above
the floor panel, so that when the tube is
introduced it is not parallel to the ground, but
slopes upwards towards the inside of the
bodyshell. The tube can now be inserted
through the plate and sill, before finally welding
into place.
Please note that both front wings MUST be
removed for this operation.
Thoroughly check items supplied against the
component parts list to make sure that there are
no shortages. It is advisable with a complex,
multi-point cage such as this to loosely assemble
the cage prior to making any attempts to actually
fit the structure to the car. Reference to the roll
cage assembly drawing will give a clear indication
of the intended final construction. You will then
be more familiar with the individual components
and where they will eventually be secured. Once
this has been established the cage can be split into
sections ready for assembly into the bodyshell.
Position the rear frame alongside the bodyshell, and tilt it forward such that the mounting
points for the rear suspension turrets are uppermost. Maintaining this position, pass the frame
through the door aperture, into the bodyshell
and locate the foot mountings onto the sill.
The frame, still tilted forward at the top,
can now be moved towards the rear of the
bodyshell, then turned to an upright position
and further rearward until the rear suspension
turret mountings can be located centrally onto
the rear suspension turret tops. Now drill a
10mm. hole on each rear turret mounting and
i nsert a bolt. The rear part of the roll cage is
now located in its correct position.
Position the foot mounting brackets (Sill
Mounts), making sure that they are seated
correctly on the sills and accurately mark out
the six attachment bolt holes. Detach the rear
turret mountings and move the frame forwards
so that the six holes marked out can now
be made to 25mm diameter. Attach the foot
mountings to the rear frame and bolt up fully
before returning the frame to its fitted position.
Drill out the remaining rear turret mounting bolt
holes and fully attach with the 10mm bolts. The
foot mountings can now be welded in position
to the sills. It is important to clean this area
thoroughly to ensure good welding conditions
for this operation.
Now the two rails can be positioned and
attached to the rear frame with bolts. Fit the
front roof rail to prevent the side rails from
falling inwards, whilst the front frame foot
mountings are positioned on the sill. Mark out
and attach these to the sill in the same manner
as at the rear.
Two mounting blocks are provided, with tabs
to give additional attachment for the side rails.
These attach to the roof stiffening rail above
the door aperture. Position these, drill the two
holes and bolt into position. The door rails and
the front roof rail should be loosely bolted in
position at this stage.
There are two forward facing brackets on
each of the side rails, which are to carry the
arms that attach to the front suspension turret
area. The upper bracket on each side should
i deally be close to or in contact with the actual
door pillar at that point. However, because of
tolerances in both the bodyshell and rollcage a
spacing washer may be required to `bridge the
gap' prior to tightening the attachment bolt to
the door pillar. Using this bracket as a guide, with
extreme caution, pass a 10mm. drill through the
bracket and drill outwards through the shell until
the point of the drill JUST starts to SHOW on the
outside of the shell, then STOP drilling. Using a
hole saw, the drill bit acting as centre, open out
this hole to 25mm from the OUTSIDE of the
car through only TWO of the panel thicknesses,
LEAVING the pilot hole in the INNER skin at
10mm diameter.
The front suspension turret/front tower arms
can now be fitted. A template is supplied to assist
i n marking out the holes required through the
bulkhead area and into the windscreen wiper
motor well for these front support arms. The
template is for the RIGHT side of the car looking
forwards, the position for the other side can then
be judged having completed the operation on this
right hand side unit. Take extra care when cutting
out these holes, it is better to make them too small
i nitially and progressively increase them to give
a close-fitting. This then leaves less of a gap to
be filled after final completion of the roll cage
installation, and maintains compliance with the
fireproofing requirements. Now feed this support
arm into position from the front of the car and
bolt to the side rail top mounting. Mark out
the two holes alongside the suspension turret
and drill out to 10mm. A third 10mm. hole has
to be drilled at the point where the diagonal
support meets the front tower arm, but opened
out to 25mm on the outer skin of the chassis
member, to enable the fixing bolt to be inserted
and tightened. Bodyshell and rollcage tolerances
again may require spacing washers to be fitted to
` bridge the gap' between the tower arm and the
body panel prior to tightening the attachment
bolt. Again, use the 10mm. hole as the pilot
hole for the hole saw. The diagonal support
arm can now be passed down through the wiper
motor well area to the lower attachment point,
the front tower arm can then be positioned and
the assembly fully secured. Repeat this procedure
for the other side of the car.
Four heavy gauge washers and fixing blocks
are now left. These are for additional attachment
of the sides of the rear frame. Drill 10mm holes
through the INNER SHELL ONLY, at the four
rear frame side mounting points. Pass the upper
fixing block upwards inside the shell, position a
heavy gauge washer between the shell and the
frame, then retain by inserting the bolt. Repeat
for the lower fixing points. Check that all bolts
and component parts are in place and that you
are content with the general fit.
Now go round ALL attachment points and
thoroughly tighten all bolts.
The strengthening and preparation is now
complete but it is suggested that the roll cage
i s removed whilst the bodyshell is painted.
This is the last item under the general description
of body strengthening, and must be fitted to the
car by attaching to the front suspension top
mounting bolts. This can be left until all the other
operations have been carried out. Spacers may be
required to give adequate clearance between the
brace and the manifold on certain vehicles.
An undershielding kit has been developed for the
Group A car. This front shield protects the engine
sump and transmission assembly, and attaches by
four bolts to the front mounting points for the
forward facing, lower suspension arms. The rear
of the shield is attached by two bolts, adjacent to
the inner pivot points for the lower wishbones.
A threaded insert is already incorporated in the
strengthening plate supplied for this area and
should have been fitted during the bodyshell
preparations. The rear attachment points are
not pre-drilled in the sumpguard. These must
be marked out to suit the individual vehicle with
the front of the sumpguard correctly attached.
The holes must then be drilled out to size (12 to
12.5mm) for positive location of the sumpguard,
since this then becomes an integral part of the
NOTE: The hole positions can easily be
marked on to the shield by the following method.
Remove the head from a 12mm bolt, screw
this remaining threaded portion into the rear
attachment point leaving approximately 5mm
of thread above the surface. Fit the shield to
front attachments and apply pressure to the
rear of the shield at each attachment point,
the threaded section should then clearly mark
the shield accurately where the holes should be
The lighter gauge rear shield is profiled to fit
around the fuel tank area. The rear part of the
shield attaches to the rear tank mounting points.
Three holes must be drilled on either side of the
shield, for bolting through the floor.
The basic concept of the standard road car's
suspension layout has been retained but
extensive modifications have been made to the
way that the components have been constructed.
A revised front suspension assembly has been
designed, fabricated and homologated
specifically for use in Group A motorsport, and
MUST be used as a complete package. There is
no compatibility between individual components
and those found on the standard car.
This new assembly consists of a modified
knuckle assembly, fabricated lower control arm
i ncorporating spherical joints, an adjustable,
tubular lower suspension arm/castor control link,
complete with spherical bearing and reinforced
front attachment bracket. The heavy duty front
strut body with adjustable spring platform
position, is fitted with a De Carbon monotube,
gas filled shockabsorber insert. This attaches to
the knuckle assembly and incorporates a wheel
camber adjustment facility in the top securing
bolt. The alloy top mounting uses a spherical
j oint housed eccentrically to allow further castor
and camber adjustment. The knuckle assembly
supplied in the kit is derived from the normal
production component but has been further
machined within the wheel bearing housing to
accept the larger diameter wheel bearing, and the
top mounting bolt hole enlarged to 14mm.
To complement this package, a selection of
`superprogressive' road springs and suitably
matched dampers have been developed to cover
tarmac and gravel applications.
These springs are constructed from tapered
wire and offer a wheel travel capability coupled
with increased spring rate, unattainable from
conventionally constructed, constant wire
diameter springs.
Ensure that all components are thoroughly
cleaned and bushes lightly lubricated prior to
assembly. Assemble under clean conditions at all
times. The spherical joints are located both in the
lower control arm and strut top mounting plate
by circlips. Attach lower control arm to chassis
pick-up point using the larger 12mm bolt
supplied. This hole should have been enlarged to
suit this bolt during the bodyshell preparation.
Prior to assembly, fit the front wheel bearing
to its housing in the knuckle and retain with the
two circlips. At this stage, press the drive flange
into the wheel bearing, and fit the wheel studs to
this assembly. Fit the threaded insert into the
mounting post clamp from the TOP face, secure
by clamping with standard pinch bolt. The
knuckle assembly can now be attached to the
lower control arm by a cap headed bolt and
washer inserted through the underside of the
outer spherical joint, into this threaded insert.
The lower suspension arm is attached to the
lower control arm at one end by a bolt, but the
spherical joint at the opposite end locates with a
bracket attached to the front crossmember.
This has been profiled to fit the crossmember
AFTER the strengthening plate for this point has
been attached, and has been designed to fit in
this original position using the three original
mounting bolts. This bracket is also designed to
be used as the front attachment for the
The shockabsorber insert should be fitted to
the strut body, to be secured by a single nut, but
lightly lubricate the bearing surfaces and make
sure that the bump stop rubber is in place on the
shockabsorber rod before assembly. The lower
spring guide ring, chosen road spring (spring
clamp required for this operation), top spring
plate, followed by the top mounting assembly
can then be secured by a single nut. There is
provision for a grease nipple to be fitted to the
top part of the strut body, just above the
threaded section. Access to this nipple can be
made between the lower coils of the road spring
for occasional lubrication with a proprietary
graphited grease.
The completed shockabsorber and spring
assembly is attached to the knuckle using the
special bolt supplied. This 14mm. top bolt is
handed since it has an `eccentric' head to enable
wheel camber adjustment. The offset head of
this bolt fits between the two small angled plates
on the strut body, the lock nut and special
hardened washer supplied should be fitted to the
plain side.
These bolts must be tightened by a torque
wrench immediately after the geometry has been
set to the required figures. This is a very critical
area on the suspension, and as a precaution the
torque figure should be checked as a service
operation during vehicle use.
Top Bolt,
Bottom Bolt,
14mm to 18kg/m. (130 Ib/ft.)
12mm to 12kg/m. ( 90lb/ft.)
As a direct result of National and International
rallying experience with this model, the GM
Eurosport development engineers in conjunction
with their `team' drivers have optimised the
suspension settings for different types of event
and surfaces. It is suggested that these are
adhered to particularly for the first competitive
outing, after which some drivers may prefer to
make their own subtle changes to these settings
to give slightly different handling characteristics.
The package has been developed for optimum
performance without a front anti-roll bar.
When setting the castor and camber angles, it
is vitally important that both sides of the car
measure similarly. The tracking figures should
also be regularly checked, sudden discrepancies
i n the measured data could indicate that some
component has been damaged. In Group A
specification this is a very responsive vehicle and
to maintain driver friendliness attention to the
geometry settings is a priority.
Gravel and Off-Road Events.
Reference Number: 5XS03AC031
European Tarmac Events.
Reference Number: 5XS03AC032
Smooth Tarmac.. Spain or similar.
Reference Number: 5XS03AC033
NOTES: The springs have been designed to give
optimum performance and correct vehicle ride
height, when the lower spring guide ring or
platform is set at 140mm. This is when
measured from the top edge of the spring
platform to the knuckle attachment lugs.
When setting the suspension in the first instance,
it is suggested that the top mountings he
positioned such as to give maximum positive
castor. That is with the top of the strut as far as
possible towards the rear of the suspension turret
aperture. Further adjustment can then be carried
out at the knuckle and the spherically jointed end
of the lower arm as required.
2mm toe out
4 degrees +ve.
1 1 /2 degrees -ve.
2mm toe out
4 degrees +ve.
2 degrees -ve.
NOTE: For predominantly radiused road surface, as found in Ireland for example, reduce front
wheel camber to 1 1 /2 degrees -ve.
A power assisted, high ratio, steering rack system
has been designed and developed as a complete
package for the Group A car. This includes the
steering rack, steering pump, external power
ram, oil reservoir, mounting brackets, all oil
pipes and fittings. The power assistance
characteristics closely match those developed for
the Group A Kadett GSi and Astra GTE models.
This minimises the torque steer effects usually
associated with high powered front wheel drive
cars and considerably reduces driver fatigue.
Before attempting to fit the steering rack
assembly, the hole in the bulkhead where the
steering column enters the engine compartment
must be enlarged significantly to accommodate
the power steering valve body. A template of
this hole is provided as a single removable page
in the rear of the manual. To prevent the
possibility of the power assistance ram becoming
loose at its attachment points on to the actual
steering rack, the two bolts must be removed and
drilled prior to reassembling, and then safety
wired. The steering rack assembly can now be
placed on its mountings, but before tightening
the securing nuts establish that the rack body sits
correctly on the bulkhead mounting positions.
Tolerances in the body shell may dictate that
some metal may have to be removed from the
steering rack body to improve this condition.
The steering rack can now be attached to the
bulkhead. A body sealing rubber gaiter is
provided and fits over the valve body from the
inside of the vehicle prior to fitting the column
assembly. This gaiter will require slight
, trimming' to achieve a satisfactory fit around the
valve body, prior to attaching it permanently to
the bulkhead using adhesive or other means.
The oil reservoir can be attached to the left hand
suspension turret using the bracket supplied. All
the pipes are made to the correct length and have
the appropriate end fittings such that they can
only be fitted in the correct way.
The power steering pump is attached to the
engine by two bolts and driven from the
crankshaft pulley by a common `poly-vee' drive
belt that also drives the alternator.
Two universal joints and two mini-shafts are
provided to connect the steering column to the
power steering rack assembly. One shaft fits
between the two U.J's, the other fits into the end
of the steering column having first removed and
discarded the original lower column shaft.
NOTE: On certain vehicles, the replacement
l ower column shaft may require further
machining before it can be correctly fitted into
the existing lower column support bush. In this
case refer to the diagram showing the revised,
machined condition.
The steering column can now be connected
to the power steering rack by attaching the two
U.J's. Tighten all clamping bolts thoroughly!
Initially the system will require bleeding to
remove any air pockets. Top up the pump
reservoir with new fluid (Dexron 90 020 172), to
the edge of the filler neck. Start engine and
immediately switch off, repeating this procedure
until the fluid level is at the `MIN' mark with the
engine stationary. To bleed the system, start
engine and allow to idle whilst the steering wheel
is turned from lock to lock. Finally check the
fluid level in the system when the system is cold
and the engine not running. The level should
then reach the `MIN' mark. At normal operating
temperature the level should not be above the
' MAX' mark. If the fluid level drops particularly
low, check the system for leaks. Under no
circumstances allow the pump to be driven with
insufficient or no fluid in the system.
NOTE: Do not use the vehicle with the power
assistance disconnected, this could lead to
damage within the valve assembly.
The standard rear axle beam is retained for the
Group A specification, and does not require
additional strengthening. Special competition
bushes are supplied in the kit, and should be
fitted to the body mounting pivot point of the
rear axle. De-carbon gas filled shockabsorbers
have been developed in conjunction with
superprogressive `minibloc' rear springs for
gravel and tarmac events. These must be used in
conjunction with the corresponding front springs
and shockabsorbers, as they are part of a fully
integrated package. The 18mm. diameter antiroll bar, standard fitment on the GTE/GSi
models, must be fitted for tarmac surface
applications. However, certain drivers may also
prefer the loose surface handling characteristics
resulting from running with a rear anti-roll bar
Wheels have been specially produced for this car
by O.Z. These are available in 15 inch diameter,
with a 6 inch rim width. Experience has shown
that this gives the best possible wheel/tyre
configurations from a performance point of view
for both tarmac and loose surface use. They also
give compatibility with a wide range of tyres and
sizes permitted within this engine capacity class
from most major tyre manufacturers.
Fifth gear @ 7600 RPM
Final Drive
Racing Tyres
Gravel Tyres
Gravel and Off-Road Events.
Reference Number: 5XS04A0004
All Tarmac Events.
Reference Number: 5XS04A0005
NOTE: An additional spacer may be required
under the springs to achieve the correct rear ride
height and appearance when using the European
tarmac front spring.
All conditions of use.
CAMBER: From 0 degrees 40 mins. negative
to 1 degree 35 mins negative.
( Maximum deviation Left to Right, 30 mins.)
TRACKING: From 0.5mm. (5mins.) Toe Out
to 4.Omm. (40 mins.) Toe In.
These parameters cannot be adjusted, and if they
fall outside of the above limits it would suggest
that the rear beam has become distorted.
Racing tyres
Gravel Tyres
2.0 Bar
1.8 Bar
1.6 Bar
1.6 Bar
A dual circuit hydraulic system, with in-car
brake balance control, actuates Automotive
Products four-pot calipers at the front, fitted to
267mm diameter by 25.4mm thick ventilated
discs. Solid rear discs, 251mm diameter by
9.6mm thick are supplied complete with
appropriate caliper mounting brackets and alloy
hubs. An hydraulic handbrake conversion kit is
supplied, and includes the modified bracket,
spacer and hydraulic cylinder. Aircraft
specification, stainless steel `Aeroquip' type brake
pipes have been developed and come as a
package, complete with all the necessary elbows
and bulkhead fittings. The designated brake pipe
layout is shown in the accompanying diagram,
and the individual pipe lengths have been
optimised for installation in accordance with that
Care must be taken whilst handling ALL brake
system components, and before connecting
i ndividual pipes and fittings together it is
suggested that they are `blown out' with an
airline to ensure they are free from dirt, etc.
Lay the flexible pipes roughly in place inside
the shell to get the general idea as to where they
will be finally sited. Reference to the general
schematic diagram will indicate the position in
more detail. Because the pipe lengths are fixed, it
is advisable to partially secure the pipe-run to the
bodyshell before marking out the positions
where the pipes pass through bulkhead panels.
Holes can then be made for the appropriate
bulkhead fittings, and once the pipes are
connected up in their correct positions, they can
be finally secured neatly, to the panels using
proprietary clips.
The twin master cylinder pedal-box assembly
attaches to the original brake servo mounting
studs. The 0.7" cylinder is for the FRONT
brake system, the 0.75" cylinder is for the REAR
brake system. A flexible drive cable, fitted with a
hand control that can be mounted on an
auxiliary bracket or on the centre console,
connects to one end of the brake balance
adjustment beam. This operates the brake
balance adjustment beam from within the car.
Special brackets are supplied to convert the
handbrake to hydraulic actuation. The master
cylinder support bracket should be welded to the
centre tunnel, behind the handbrake lever. Refer
to the photograph for exact position. The 5/8"
master cylinder attaches to this bracket complete
with the spacer block. The pushrod is then
attached to the handbrake lever using the
adaptor brackets supplied, and they should be
welded to the handbrake lever. They should be
positioned such that when the handbrake lever is
in the `OFF' position the pushrod is `FULLY'
extended from the master cylinder. Remember,
this handbrake is NOT fly-off action, and should
this be required is left to the discretion of the
vehicle builder.
The front brake disc, is first attached to an
alloy adaptor plate which is then placed over the
drive flange. The brake caliper can then be fitted
over the disc assembly and attached to the
knuckle using the high-tensile cap headed set
screws. The front discs are handed, and to
maximise the brake cooling advantages must be
fitted such that air is drawn through the disc
from the inside of the disc, by the webs in the
casting during forward motion of the vehicle.
The front brake pipes must be connected as
shown in the diagrams and photographs.
However, check the installation to ensure that
they have sufficient articulation throughout the
available suspension travel and wheel lock
A special alloy bracket is provided to attach
the rear brake calipers to the rear suspension
beam. These brackets fit between the stub axle
and the rear axle beam. Fit the wheel bearings
and the grease seal into the alloy rear wheel hub
supplied, and fit the wheel studs.
Assemble on to the stub axles, securing the
outer taper roller bearing with its locking
washer, castle nut and split pin, following the
normal service procedure at all times for this
operation. The brake discs and calipers can now
be fitted. Connect up brake pipes and secure
neatly to rear axle beam where required.
NOTE: The brake master cylinder combination
supplied will give adequate brake balance
compensation for almost every surface condition.
However, should the balance become a problem
on events that include a large percentage of
extremely tortuous downhill sections on dry
tarmac, the rear braking can be reduced even
further by fitting a 7/8" master cylinder to the
REAR brake system.
From our experience we would suggest fitting
Ferodo 2459 material for both front and rear
brake pads. This will give good all round
braking performance and satisfactory brake
balance control for both tarmac and loose
surface conditions. There are of course,
alternatives - Ferodo 3466 is a softer material
and DS 11 a much harder material.
Under some operating conditions a harder
material on the front pads may be a
consideration. However, since there is the
possibility that the DS11 material may not
always be running within its optimum
temperature range, the brake balance could
become inconsistent, and very REAR biased,
even to the extent of continuous rear wheel
locking. Should these circumstances prevail, the
choice of DS 11 has not been the correct decision.
Revert to the recommended Ferodo 2459.
The Group A engine specification has been fully
developed in the International rallying arena
during 1989 and has shown to be powerful and
very reliable. The special components required
to build a replica power unit form the basis of
the Group A engine parts kit. Heavy duty engine
mounting rubbers are included and fit as a direct
replacement for the standard components.
Competition engine preparation is really a
very specialised operation and requires
equipment and skills beyond the scope of a
skilled vehicle mechanic. In spite of this, to
assemble the Nova/Corsa 1600 engine and
Group A parts kit, would be a relatively easy
task for most competent vehicle mechanics. The
basic engine design, the machined, cast and die
cast finishes are to such a high standard on the
production unit that the need for excessive
i ndividual component preparation is minimal.
By following the guidelines of this chapter, using
the special components supplied, correctly
assembled would produce a fairly powerful and
reliable power unit. The basic cylinder head is
very efficient in it's standard form, and the
procedures outlined in this chapter do not extend
t o further modification of the standard
Obviously there is scope for optimisation of
power output by subtle modifications to both the
cylinder head, manifolds, and valve installation,
although ALL dimensions must conform to those
homologated. The nature of the possible
modifications is such that they should ONLY be
carried out by a competition engine preparation
specialist. Cylinder head and manifold
modification, to realise a worthwhile gain in
power, requires knowhow combined with careful
and laborious attention to detail. Yet to throw
power away by an incorrect approach to the
modifications is all too easy.
Please remember, that a good competition
engine can only be developed from a good
standard production unit. If at all possible
always use a new or very lightly used engine unit
as the basis for conversion to Group A
specification. Cleanliness and careful assembly is
the keynote to successful engine assembly.
A correctly prepared and assembled unit should
produce between 140 and 150 BHP, with
maximum power developed at between 6800
and 7000 RPM.
Before commencing the stripdown of the
standard engine unit and whilst the engine is in
running order, ensure that the ignition timing is
correctly adjusted. This should be 10 degrees
BTDC at idling speed. Then mark the
distributor-to-cylinder head position so that this
correctly timed position is not lost when the
distributor is removed. Failure to do this will
prevent correct repositioning of the distributor
after the rebuild, and it would then require access
to special electronic instrumentation to establish
the position.
The big-end caps, whilst they are each
matched to their conrod during machining, are
NOT marked when fitted to the standard
production engine. Before removal, mark the
big-end cap to conrod position to ensure rebuild
is in correctly matched order.
The standard sump pan is retained but requires
an additional baffle plate and pick-up pipe
protector to prevent oil surge during braking and
hard cornering manoeuvres. This specially
profiled baffle plate and the protector should be
attached by `brazing' to the sump pan in the
positions shown in the diagram. It is important
not to exceed the maximum oil level marks on
the dipstick prior to subsequent competition use.
The oil surface could easily be picked-up by the
rotating crankshaft, significantly increasing the
drag with a subsequent detrimental effect on
power output.
If there is any doubt as to the type of use that the
engine may have already had, measure the
crankshaft for wear and crack detect as a
precaution. Production balance levels are
already very good and no further balancing is
required. If the crankshaft is not as new, lightly
polish the journals with a suitable grade of
crankshaft finishing tape. Thoroughly clean the
component with petrol or other suitable solvent.
Blow out the oil passages with compressed air
prior to reassemble. The main bearing shells and
bolts are as production.
To give the correct increase in the compression
ratio and increased durability, Cosworth, full
skirt, forged pistons are supplied. These have a
lighter gudgeon pin which is a pressed fit into the
small end bearing, as in the normal production
condition. The Cosworth pistons are sized to be
compatible ONLY with the standard production
bore dimensions. These are in fact graded, but
the increased operating clearances with the
Cosworth piston easily accommodates any slight
variance in bore size.
The Cosworth piston is a direct replacement
for the standard unit, which can be discarded.
Circlip grooves are evident around the gudgeon
pin housing on the Cosworth piston, these must
be completely disregarded as circlips are not
required for this application. As a precaution the
conrods should be crack detected after the
standard pistons have been removed and prior to
assembly with the replacement pistons.
However, both the removal and fitting of the
pistons to the conrods is a specialised operation
and must be carried out by appropriately
qualified and equipped personnel. Heavy duty
conrod bearing cap retaining bolts are supplied
which also give more positive bearing cap
The pistons have a designed `deck height' to
give a compression ratio of approximately
11.4:1, and when installed should protrude
above the block face at top dead centre by
0.4mm. plus or minus 0.10mm. (0.016ins, plus
or minus 0.004ins.) This dimension should be
checked in case of block discrepancies.
The bore size must be standard to remain within
the 1600cc maximum capacity limits and should
therefore conform to the following dimensions.
78.995mm. to 79.025mm
3.11ins. to 3.1112ins.
An oversize, competition piston has not been
developed. Prior to assembly, deglaze bores to a
micro finish and 45 degree hatch pattern. The
take-off hole for the standard engine breather
tower assembly, situated on the inlet side of
the block, must be blanked off with the plate
supplied. See photograph for the detail. Assemble
i n accordance with normal build procedures.
Carefully dismantle the cylinder head, placing
each component in numbered removal order so
that the parts required can be reassembled in
their original positions.
Prior to further cylinder head preparations,
a modification to give increased oil supply to
the hydraulic lifters, thus ensuring adequate
oil pressure under high oil temperature and
sustained high engine speed operating conditions
MUST be carried out. The oil pressure feed hole
i n the cylinder head casting, situated at the
exhaust side of the cylinder head face should
be increased in diameter. This operation requires
extra care, and entails drilling out the existing
, angled' 2mm. hole to 3mm. The hole must be
enlarged throughout its depth (approximately
40mm.), until it joins with the larger diameter
part of the `gallery' section, taking extra care
to follow the path of the existing `angled'
hole. Make sure that the oil passages do not
contain any residual swarf after completion of
the modification. Follow standard procedures
for cylinder head refurbishing.
The production Nova/Corsa 1600 engine
features exhaust gas recirculation. This is part
of the emission control system, where regulated
quantities of the exhaust gasses are recycled
through the inlet tracts under certain throttle
opening conditions. The take-off position for
this system can be found on the inlet face of the
cylinder head below the inlet ports for cylinders
No.2 and 3. This hole must be blanked off, using
the alloy blanking plug provided. The hole in
the angled abutment on the camshaft housing
(camshaft case), for the standard breather system
should also be blanked off. Apply `studlock' or
si milar product to give additional retention. The
photographs show the two finished conditions.
The standard valves must be retained. They
can be slightly modified behind the valve head to
i mprove gas flow, and the stem heights above the
cylinder head face can be adjusted for optimum
performance, but these operations should only
be carried out by suitably qualified personnel,
AND with close reference to the homologated
Heavy duty valve springs, large diameter
l ower spring platforms (valve washers), modified top retainers (valve spring cups) and thrust
pads are provided and must be assembled in the
following sequence.
Place large diameter lower spring platform over
valve guide boss. Fit appropriate valve through
guide and press valve stem oil seal into place.
Fit valve spring, followed by the modified top
retainer and secure with split collets (valve stem
Place standard rotator platform over valve guide
boss. Finish off assembly as for inlet valve.
The design data for the camshaft supplied is as
a direct result of extensive dynamometer testing
and competition experience with this power unit.
Camshaft lubricant is provided and must be
applied liberally to the lobes prior to assembly.
During the fitting of this camshaft to the housing
(camshaft case), take care not to damage the
oil seal with the lobes of the camshaft. The
standard timing marks should be used for final
assembly, and experience has shown that in the
majority of cases they represent almost optimum
ti ming for this cam. Again there is scope for
optimising the valve timing, as tolerances in the
engine block dimensions do have an effect on
the actual timing. The correct timing for this
camshaft is confirmed by measurement of the
INLET valve lift at top dead centre, and this
should be 4.4mm. (0.1732ins.) when measured
with zero valve clearance.
The cylinder head is attached by heavy duty
cylinder head bolts and must be fitted along with
the heavy duty, competition gasket supplied.
Make sure that the head face is thoroughly clean
and dry, fit with dry gasket. No grease or sealants
to be used. Make sure that the head is properly
l ocated on the locating dowels before any attempt
is made to secure. Ensure that the mating faces of
the camshaft housing and cylinder head are also
thoroughly clean, then apply recognised sealant
to both faces prior to final assembly. Lightly
lubricate the thread area of the bolts to minimise
thread friction during the tightening procedure.
The bolts should be tightened in three stages,
adopting a spiral pattern sequence from the
centre of the cylinder head.
1st. stage: 3.5 kg/m. (25 Ib/ft.)
2nd. stage: 6.0 kg/m. (45 Ib/ft.)
Final stage: 9.0 kg/m. (65 Ib/ft.)
The three tightening stages should be carried
out operating the torque wrench in a CONTINUOUS angular movement until the required
torque figure has been reached. This will almost
eliminate the errors introduced by the friction
i n the threads and under the bolt head. The
gasket thickness when fully clamped is 1.2mm.
( 0.047in.) which is equivalent to a volume of
6.1 cc.
As the standard engine breather system has
been deleted, an external breather must be provided. Connected to the camshaft top cover this
pipe should then lead into an auxiliary catch
tank with a minimum capacity of 2 litres. This
container could be made out of plastic but if
made from a non-translucent material must
i nclude a transparent window for compliance
with Appendix `J' Group A. See photograph
showing additional elbow in place.
The standard oil pump is retained and is capable
of giving adequate flow and pressure for this
engine specification. However, in view of the
modifications to the oil feed in the cylinder
head casting, the oil pressure relief valve must
be adjusted to compensate. This entails the fitting
of a 3mm. shim behind the pressure relief valve
spring to increase its pre-load. The oil cooler
connects to the engine by a sandwich plate that
attaches to the block, between the oil filter unit.
The high pressure pipes are made to the correct
length for connection to the oil cooler radiator
when fitted to the left hand side of the front
panel, viewed from the front of the car. A
special attachment bracket is supplied. Before
assembly, fill oil radiator and pipes with chosen
engine oil.
Difficulty can be experienced in generating oil
pressure on initial start-up, after a major engine
rebuild. This is due to problems in getting the
oil pump and system primed. To overcome this,
it is suggested that the oil pump rotor be packed
with `light' assembly grease before the oil pump
is fitted. To do this, the backplate will have to
be removed from the pump casing to expose the
rotor assembly. Refit backplate correctly after
packing with grease.
The standard single-vee belt pulley must be
replaced by the poly-vee belt pulley provided.
This belt specification is essential as it drives both
the alternator and the power steering pump. The
power steering pump is attached by bolting to the
block face below the camshaft driven gear.
The standard item is retained. However, it is
advisable to check the weight of the unit prior to
assembly as there is a minimum homologated
weight requirement for the flywheel and starter
ring gear assembly.
Discard the E.G.R. valve assembly, situated
between the injectors for cylinders 2 and 3. Fit
blanking plate to the exposed hole, making sure
that the blanking plate is completely sealed to the
face of the manifold.
The standard injectors are inadequate for this
degree of engine performance. Injectors with a
much higher discharge capacity are supplied in
the engine build kit. These are taken from the
GSi 2000 16 valve engine unit.
The standard cast exhaust manifold must be
retained under Group A regulations, but a
modified system from the manifold is permitted
and has been developed for this engine
The Nova/Corsa' 16001engine was introduced in
early 1988 and featured the Bosch L3.1 Jetronic
fuel injection system. Since then certain
evolutionary changes have been made to the
engine management system during the
production process, as alternative suppliers have
been introduced to supply similarly functioning
components. The advent of the exhaust catalyst
to meet certain market legislation has also lead to
a completely different management system just
for the catalysed engine specification.
The Group A parts kit was initially fully
developed around the original Bosch L3.1
Jetronic system. This incorporates a Bosch
ignition ECU, Bosch ignition distributor and
Bosch air flow sensor/ECU.
Donor vehicles fitted with the Siemens
ignition ECU and Lucas ignition distributor must
be converted to the Bosch specification, as the
other units cannot be modified to match the
Group A engine requirements.
Donor vehicles running with a catalyst are fitted
with the Bosch Motronic system. While this is
far superior to the Bosch L3.1 Jetronic system, it
has not been further developed as a part of the
Clubman Group A engine parts kit. In this case
the whole system would have to be replaced by
the Bosch L3.1 Jetronic components.
There is an alternative solution for donor
vehicles that do not comply and for those
requiring a better management system than the
Bosch L3.1 Jetronic anyway. Since the
introduction of the Group A engine parts kit,
several engine preparation specialists associated
with Nova/Corsa engine building have been
developing their own alternative engine
management systems. These are all Group A
legal and in most cases the ultimate power is
slightly increased, but with significantly
i mproved mid-range performance and
drivability. Whilst there is a cost penalty for the
i mproved system it is worthwhile consideration
even if your donor car already has Bosch L3.1
Jetronic set up, simply because of the increased
performance readily available. This becoming a
more obvious decision should your donor car be
to one of the completely non-compatible
If the engine is equipped with the full Bosch
L3.1 Jetronic system, both ignition and fuel
requirements are controlled individually. The
major changes to the camshaft characteristics
and compression ratio in full Group A tune,
dictate different fuel and ignition requirements.
The ignition system is electronically programmed
by a unit mounted to the underbonnet bulkhead.
This is replaced in the kit by a similar component
matched to the requirements of this engine
specification, and is plugged in as a direct
The electronic control unit, ECU, for the
i njection system is integrated with the air flow
sensor and mounted in a cast alloy housing on
top of the air flow sensor. A reprogrammed unit
is supplied and can be fitted as a direct
replacement. Remove the standard ECU by
slackening the four attachment screws around
the housing.
NOTE: This engine has been developed to run
Before setting the idle speed and C.O. levels,
check the dynamic ignition timing. This should
be set with the engine running without load on
part throttle at 2000 RPM, and should be 32
degrees BTDC. The idle speed adjusting screw is
l ocated on the inlet manifold throttle butterfly
housing. To increase idle speed, turn screw
outwards. The C.O. levels are controlled by a
potentiometer in the ECU housing, and adjusted
by a screw concealed by a tamperproof plug.
Idle on this engine may be slightly erratic, but
should be set to between 1300 to 1500 RPM and
with 1 1/2 to 2% C.O. level.
If the engine can be run on a dynamometer,
or the complete vehicle on a rolling road, the
ignition can be further adjusted on full load at
5000 RPM and should be set to 20 degrees
Cylinder Head 1st stage: 3.5 Kg/m. (2516/ft.)
2nd stage: 6.0 Kg/m. (45 lb/ft.)
3rd stage: 9.0 Kg/m. (65 lb/ft.)
Main Bearing Cap:
8.0 Kg/m. (58 lb/ft.)
Con. Rod. Cap:
4.0 Kg/m. (30 lb/ft.)
Camshaft Pulley:
5.5 Kg/m. (40 lb/ft.)
Crankshaft Pulley:
6.0 Kg/m. (45 lb/ft.)
6.0 Kg/m. (43 16/ft.)
The standard 42 litre (9.2 gallons) steel petrol
tank is retained. The standard high pressure
delivery pump is also retained, but must be
repositioned to the area between the fuel tank
and spare wheel well. The existing mounting
bracket can be modified for use in this revised
l ocation. The fuel filter supplied should be
mounted on the special bracket and attached to
the bulkhead as shown in the photograph.
Armoured fuel lines (Aeroquip type) are supplied
to the correct length for running through the
i nside of the vehicle and for connection to the
i njection system. These can be fitted by
following the guidelines in the chapter for the
i nstallation of brakepipes.
NOTE: Under certain extreme conditions of
vehicle use, for example tortuous `Alpine' ascents
on dry tarmac, intermittent fuel surge may occur
particularly when running with a low fuel
content. Keeping the fuel level ABOVE half full
will prevent this condition.
A revised front downpipe, centre pipe and tail
silencer have been developed in conjunction with
the engine development programme. The
dimensions selected for the front downpipe and
centre pipe enhance the torque characteristics of
the Group A engine, and the engine management
system has been optimised for this system.
Whilst the total system is considered effective as
a silencing device and meets current U.K. Traffic
Regulations, it is the responsibility of the
competitor to ensure conformity with the traffic
regulations of the countries through which the
event is run.
invaluable for on event servicing or replacement
if damaged. The system can then be attached
using the standard exhaust mounting rubbers.
Mounting brackets for this exhaust system have
not been attached. Experience has shown that it
is easier to mark the exact position for the
mounting brackets with the system in place.
This allows for some variation between vehicles
and exhaust systems to be catered for.
The chassis mounted rear bracket should first
be removed from the car. Replace with and weld
into place, the modified bracket supplied. The
front bracket should be welded on to the rear
gearbox mounting centre bracket. The position
can be determined by attaching the front
downpipe to the exhaust manifold. The other
part of this bracket can then be tack welded to
the front pipe to line up with it. Now remove
the front pipe and complete the welding
operation on the bracket. Refit front pipe and
fully secure to gearbox mounting point. The
centre pipe section and rear silencer box should
now be offered into place. By twisting each
section relative to each other, the optimum
position can be determined giving satisfactory
clearance over the rear axle beam, spare wheel
well etc. Mark position for the rear mounting
bracket and tack weld in place if possible.
Remove from car for final welding operation. It
is suggested that short lengths of small diameter
tubing are welded to the pipes on either side of
the sleeve joints to create a facility for lockwiring
the pipes together rather than using exhaust
clamps. This gives a quick release attachment,
A sachs 190mm diameter, solid disc centreplate
competition clutch with heavy duty diaphragm
cover has been developed. This unit is supplied
in the Clubmans Kit and fits the standard
flywheel without any modifications. However, it
does require a special release bearing which is
supplied complete with a special bearing carrier.
This carrier requires detailed modification for it
to fit the existing gearbox casing, as follows.
One of the three locating flanges must be
reduced in thickness to give clearance against the
gearbox casing at one point. This can be
achieved by carefully grinding away the excess
material thus `thinning' the selected flange
around its outside diameter. The three
attachment holes around the carrier must then be
slotted and elongated to adapt to the smaller
pitch circle radius of the threaded holes in the
casing. Assemble by first fitting the `O' ring seal
followed by the thin spacer ring. Secure in
position by attaching the bearing carrier to the
gearbox casing with the three bolts. Clutch cable
adjustment procedure follows that for the
standard car.
A close ratio 'dog type' gearbox kit has been
specially developed for this model. This gearbox
utilises the casing and intermediate housing or
' sandwich plate' from the standard car's F13
speed gearbox but the component parts of the
close ratio kit must be assembled along with a
revised end cover and gearshift cover assembly.
As this is a heavy-duty gearbox unit, many of
the component parts are larger that the corresponding standard item. To accommodate these
some detailed internal modifications must be
carried out on the casing BEFORE commencing
assembly operations.
The following operations are required within the
area normally containing the DIFFERENTIAL
Remove the speedometer drive gear assembly
and blank off the hole with the blanking plug
supplied. The speedometer drive gear support
l ug can now be removed by grinding away
the excess material. Also 'chamfer' the region
adjacent to this blanking plug and remove
excess material by creating a 'flattened' profile
to the area immediately above the centreline
of the differential bearing housings. This will
give the additional clearance required for easy
i nstallation of the differential assembly. Clean
off all internal rough edges due to variances in
castings to give clearance for the crown wheel.
The following operations are required within
the area normally containing the GEARBOX
The reverse gear shaft support housing is
already machined to 'convex' profile, this must
be further modified by grinding to a 'rounded'
profile. To ensure COMPLETE engagement of
the dog teeth in 4th gear, the 1st/2nd and
3rd/4th gear selector shaft support housing must
be spot-faced, removing 1.5mm from the entire
face of the casting at this point. The casting must
also be relieved by further radiuses in the corner
of this area, to give additional clearance between
the casing and the selector fork enabling it to butt
against this machined face. The amount to be
removed can easily be determined by inserting
the selector fork and shaft into position in the
casing as a guide. Since the 4th gear wheel is larger
than the standard item, a considerable amount
of material must be removed from the casing at
the point where the gear cluster encroaches into
the differential housing. Approximately 2mm
clearance is called for when assembled, and this
clearance can be viewed through the aperture in
differential case when the gearbox cluster is fitted
i nto the casing.
The mainshaft bearing housing will foul on
the 1st gear wheel unless the casting marks
are removed by rounding off the affected area
before assembly. The amount of material to be
removed can easily be confirmed by offering up
the mainshaft complete with the gear. All the
above mentioned points are highlighted in the
illustrations for this chapter.
It is very important that all the parts required
are thoroughly cleaned prior to commencing
reassembly of the gearbox and a clean, swarf-free
area is reserved for the build.
Carefully remove all gears from the mainshaft,
since they have only been fitted loosely to the shaft
for packaging purposes. It may be prudent to note
the sequence of this assembly and confirm with
the diagrams provided.
The final drivegear pinion is integral with
the mainshaft, but prior to further assembly
carefully fit the spacing washer behind the
gear, making sure that the small locating ball
i s correctly located in the small hole provided in
the shaft and spacer, thus preventing the spacer
from revolving.
Now lightly lubricate the roller bearings and
slide over the mainshaft, along with the gear
wheels and selector hubs in the order and
position shown by the exploded diagrams and
NOTE: If the donor gearbox has already covered a significant distance, renew the mainshaft
and 1st motion shaft bearings as a precaution.
Now at this stage the mainshaft bearing can
be fitted into its housing in the sandwich plate
and secured with the correct circlip. For ease
of assembly, press the other bearing on to the
1st motion shaft and loosely position its large
retaining circlip behind the bearing in readiness
for final assembly. This circlip CANNOT be
fitted AFTER this shaft and bearing have been
pressed into the sandwich plate. The sandwich
plate must now be supported in a vice with
the gearbox side facing towards you. Take
hold of the two assemblies, (mainshaft and
1st motion shaft) and whilst holding the two
`in mesh', simultaneously introduce the shafts to
their respective positions `through' the sandwich
plate. That is the mainshaft into its bearing, the
1st motion shaft and bearing into its housing,
securing the 1st motion shaft with the large circlip
behind the bearing.
Now reposition this assembly in the vice,
turning it through 180 degrees such that the
gear clusters are behind the sandwich plate and
facing away from you.
Place the 1st/2nd gear selector fork around
its hub and press the selector shaft through this
fork and into the sandwich plate. Ensure that the
detent grooves are uppermost and then carefully
secure the fork to the shaft with two roll-pins.
The 5th gear selector rod assembly can now
be inserted through the sandwich plate and
the 3rd/4th gear selector fork placed around
its hub.
Engage 2ND GEAR and push the mainshaft
away from you to the full extent of the available
free movement. This will give better access to
i nstall and secure the interlock pin assembly
to the sandwich plate with two cap headed
bolts. Once this is fitted, the mainshaft can
be returned to its correct position up against
the bearing, and the 1st/2nd gear selector rod
returned to the NEUTRAL position. The 3rd/4th
gear selector rod can now be inserted through the
axis of the 5th gear selector assembly, into the
3rd/4th gear selector fork and secured with care
by roll-pins. The 5th gear pawl assembly should
now be attached to the sandwich plate using two
cap-headed bolts, making sure that the slot in
the 3rd/4th gear selector rod located the end of
the pawl.
The 5th gear complete with its hub and
selector fork can now be fitted to the end of
the mainshaft. The selector fork locates on the
end of the 5th gear selector rod assembly. Secure
the gear to the shaft with the 33mm nut, NOTE
LEFT HAND THREAD, and tighten to a torque
of 14kg/m.(100lb/ft.), THEN indent the locking
collar. Insert the small blanking plug into the
hole in the end of the 5th gear selector shaft
assembly, Please ensure that the small holes in
the shaft, blanking plug and selector fork ALL
align with each other BEFORE securing with two
The other 5th gear can be fitted with the
spacer ring to the end of the 1st motion shaft
and secured by a circlip. Fit the reverse gear
to its shaft with the thick spacer positioned
between the gear and the sandwich plate. The
reverse gear thrust washer must not be fitted, as
it would prevent full engagement of the gear in
this gearbox. Carefully insert this shaft assembly
i nto the hole in the sandwich plate making sure
that the small LOCATING BALL is aligned with
the machined groove in the sandwich plate. Using
a copper faced hammer, drift the shaft fully into
the hole.
The long interlocking pin can now be inserted
i nto position through the reverse gear detent
hole. Fit reverse gear selector fork to shaft, fit
i nto sandwich plate and secure fork to shaft with
The FOUR detent pins and springs can now
be inserted. and retained using the force-fit
The gearbox cluster assembly is now complete and can be checked for correct operation
before final installation into the gearbox casing.
NOTE: This unit must be fitted to the
gearbox casing BEFORE the special end cover
is attached. To re-check clearance of 4th gear to
casing, refer to previous instructions regarding
casing modifications.
In conjunction with this gearbox a revised
gearshift mechanism has been developed
ensuring precision gearchange characteristics and
better durability.
The standard gearshift cover assembly is
replaced by a modified assembly supplied as a
complete unit. This is a heavy duty construction,
and is compatible with the redesigned
gearchange linkage.
Alternative final drive ratios in heavy duty form
and a six-pack limited slip differential assembly
have been fully developed for use in conjunction
with this gearbox unit.
The increased size of this crown wheel does
not allow sufficient space to retain the
speedometer drive gear. The limited slip
differential is supplied fully assembled and is preset to give approximately 75% lock-up. This
figure has been determined by extensive rallying
experience with the model and gives good
traction characteristics, yet remaining easy to
drive. There is scope within the limited slip unit
for this figure to be altered, by alternative shim
configuration, but would suggest that the 75%
figure will more that satisfy the needs of the
majority of drivers.
Assembly of this differential unit to the
crown wheel follows the normal service
procedure for the Nova/Corsa model.
Don't forget the general rule that if the donor
transmission has already covered a considerable
distance, rebuild with new bearings. If in doubt,
fit new.
duty differential assembly CANNOT be FITTED
to, or REMOVED from the differential housing
until the gearbox assembly is withdrawn from its
casing by a minimum of 5mm.
To transmit the extra power developed by the
engine in Group A trim, it has been necessary to
design and develop special heavy duty
driveshafts. These are fitted with much larger
constant velocity joints and special drive flanges
running in larger diameter wheel bearings. These
shafts are capable of handling the torque from
the 2-litre engine, so the competition life in this
application is considerably improved.
The driveshafts must be fitted in accordance
with workshop procedures for the standard car.
Three `Apex' joints, shaped connecting rod, long
straight shaft, short hollow shaft, shaft support
bearing and housing, gearchange lever assembly
and joining block are supplied. This is a
complete assembly and can only be used as such.
This can only be fitted in the first instance,
AFTER the engine and gearbox have been
installed. Attach the shaft support bearing and
housing to the forward mounted bracket
previously welded into place during the
bodyshell preparations. Fit one `Apex' joint
between the short shaft from gearshift cover and
one end of shaped connecting rod. The long
straight shaft should be lightly lubricated and
positioned through the hole in the centre tunnel,
through the forward positioned spherical bearing
and finally connected to the shaped connecting
rod using another `Apex' joint. The gearchange
lever assembly can now be joined to this straight
shaft using the remaining `Apex' joint and the
short hollow shaft which slides over the end of it.
This forms a sliding joint for gearchange
adjustment purposes, and can be firmly fixed in
the desired position using the clamping block.
gearchange assembly is to be attached to the
centre tunnel, the gearbox should be placed in
NEUTRAL gear position, the gearchange in
NEUTRAL position and the sliding joint
provisionally clamped in mid position. With the
gearchange assembly firmly attached, check the
availability of the six gears. Any final
adjustments to the linkage can be made by first
slackening the four bolts on the sliding joint
clamping block, this will then allow the lever to
be repositioned.
The Homologated ratios for the heavy duty
gearbox are as follows. It is important to
remember that these are internal and not the
overall ratios.
1st . . . . 2.54:1
2nd .... 1.76:1
3rd .... 1.42:1
4th .... 1.19:1
5th .... 1.04:1
Rev .... 3.31:1
29:13 x 43:29
Several optional final drive ratios have been
homologated but the crown-wheel and pinion
sets that equate to the ratios are not necessarily
readily available.
The following ratios are currently being used
Gravel. 4.64:1
Tarmac. 4.36:1
Cq• 7500 RPM
Final Drive
Racing Tyres
Gravel Tyres
4.36:1 Final Drive
18/56 - 14 Michelin Racing Tyres
The standard wiring loom and 55 ampere
alternator are completely satisfactory and need
only be modified when several extra electrical
components are to be fitted. Under certain event
conditions, four additional driving lamps, a short
wave radio and additional navigational
i nstruments may be required. Under these
circumstances we would advocate the fitment of
a 90 ampere alternator and additional individual
wiring harnesses appropriately relayed and fused.
The 1600 model is fitted with a 44 ampere hour
capacity, maintenance-free battery. This is
completely satisfactory for all competition
When refitting the wiring loom following a
major vehicle rebuild such as this, certain
precautions must be taken to ensure satisfactory
performance of all electrical components.
Wherever possible secure the wiring to the
bodyshell using proprietary clips and always use
grommets where the wiring passes through metal
panels. Additional care when making cable runs
will pay dividends... neat, tidy and secure means
safe and reliable! Ensure all plug-in connectors
are clean and completely engaged when
assembled. Special attention must be given to all
the earthing points around the vehicle, as some
of these may have become insulated during the
painting process. Thoroughly scrape away
excess paint from these positions to ensure a
good connection.
Certain additional electrical items are
obligatory under FIA Appendix J regulations
concerning safety. A general circuit breaker must
be fitted to cut out all electrical circuits and must
now be wired in such a way that it also stops a
running engine.
A foot switch to operate the horn from the
co-driver's side of the car must also be fitted. To
fit these and other important items, the following
procedures should be adopted.
An ideal position for mounting this is the centre
console, just above the gearlever linkage (see
Using the existing wiring loom, take the thickest
battery +ve lead (16mm) and re-run it through
the bulkhead to the switch terminal.
Connect the other switch terminal directly to the
starter motor using similar 16mm cable. Replace
the link lead from the starter motor to the
alternator with 16mm cable. This will now be
suitable for use with a larger output alternator if
Now take the remaining smaller diameter
(10mm) battery +ve lead, re-route and attach it
directly to the alternator.
To ensure that the engine is also cut when the
master switch is moved to the off position, the
coil -ve terminal must be connected to one of the
two small `W' contacts on the master switch.
The second `W' contact must be connected to
chassis ground.
A coil -ve terminal can easily be found on the
rear face of the instrument cluster as this lead is
also the tachometer pulse supply lead (light
green). Run an additional wire from this
connection point to the appropriate `W' terminal
on the master switch, following the path of and
taped to the existing harness where possible for
NOTE: Certain event regulations require that
this switch can also be actuated from outside the
vehicle. In this case a choke or bonnet release
cable assembly can be adapted to operate the
switch from a cable pull mounted on the
This switch requires a lead from the -ve side of
the horn (brown/white), and a return to chassis
ground. We would suggest making the
connection with the -ve side of the horn in the
region of the horn push, where the lead emerges
at the top of the steering column and connects to
a contact ring, rather than breaking into the
harness at the lower end of the steering column.
Again follow the path of and tape to the existing
harness for support.
Take two feeds, one from each main terminal on
the master switch and connect into a fuse box.
This then gives the option of a permanent live
feed (for radio) or switched feed (for
The main supply should be taken directly from
the master switch and connected to the power
i nput supply of the relay/s. To comply with
technical vehicle regulations, additional driving
lights should be switched off when the headlights
are on dipped beam. Control switching of the
relay/s must therefore be taken from the main
beam circuit, and we would suggest taking this
supply from the input side of fuse number three.
The wire will require soldering to this terminal.
By using double throw switches with on-offon sequence, they can be fitted such that in the
UP position the additional lights are switched on
and off by the main beam (i.e. legal) and in the
DOWN position they would be on at all times
regardless. Refer to the line diagram showing a
typical auxiliary lights wiring circuit for a `works
team' car.
The introduction of the face-lifted Nova/Corsa
GSi model range for the 1991 model year also
gave the car a completely revised interior trim
package including a redesigned dashboard
assembly. In Group A, the standard dashboard
must be retained, although different instruments
may be fitted to it, and in a different layout.
However the trimmings below the dashboard
and which are not a part of it may be removed.
The standard centre console can therefore be
removed and replaced by a panel for the
mounting of auxiliary components, such as the
battery master switch, fire extinguisher controls
and fuses etc.
As the speedometer is inoperative, reference
to the tyre section will give the miles/kilometres
per hour per 1000 RPM in 5th gear so that the
rev counter can also be used as a speed indicator.
A Group N car is fundamentally a standard
production car fitted with obligatory additional
safety items such as a roll cage, safety harnesses
and plumbed-in fire extinguishers, to comply
with specific FIA Regulations for Touring Cars Group N. In addition you will have to carry out
some further permitted modifications to make
the car more competitive.
Starting with the engine, not a great deal can
be done to a normally aspirated engine under
Group N regulations apart from blueprinting,
which is not cost effective. The basic engine
design and component finish is to such a high
standard that the need for excessive individual
component preparation is minimal. However,
there is some scope for a power increase as a
result of re-programming the ignition and fuel
electronic control units, and these modified
components are now generally available on the
Suspension modifications are permitted, in
that the springs and shock absorbers may be
replaced with uprated units, but their working
principle and attachment points must remain
unchanged. The ride height of the vehicle must
conform to the homologated dimensions.
Flexible bushes at the suspension pivot points
may be changed for mechanically similar bushes,
but made from a harder compound.
The dimensions of the brakes must remain as
normal production specification for the model
but the pad/lining material can be changed. The
handbrake may be converted to 'fly-off' action
and aviation type brake lines are permitted, but
no form of brake balance adjustment is allowed.
The exhaust system can be modified from the
first silencer box to the exit, provided that the
pipe size does not exceed that forward of the first
silencer box.
The reinforcement procedures and the body
strengthening components featured in the Group
A Kit, outlined earlier in this manual for the
Group A car can be followed, as seam welding
and strengthening of the suspended part is
allowed under Group N regulations. Please note
that the carpet and gearlever gaiter supports
referred to in that section CANNOT be
removed. The seat mounting system can be
modified to accept seats from a different source,
but the alternative seats must have at least the
same MINIMUM weight as the original seats.
This can be achieved by ballasting if necessary.
Ballast must be securely attached to the
replacement seats for both safety and eligibility
reasons. All the interior trim must be fitted to the
car, including the rear seats, although they may
not necessarily function as a seat once the roll
cage is installed!
The Group A Clubman Kit safety roll cage can
be fitted, and holes through the trim panels can
be made if necessary to enable this component to
be attached. The section in this manual
specifically outline the fitting procedure for the
Group A car, but applies equally for a Group N
A front suspension brace is permitted
between the suspension mounting points on
condition that it is fixed exclusively by bolts on
to the suspension mounting points.
This section of the manual applies equally to
Group N preparation. Brakes, transmission,
exhaust, suspension and engine preparation
chapters are exclusively for the Group A car and
have no compatibility with the requirements of
Group N.
GM Eurosport do not have any specific
components for the Group N car, although
certain components from the Group A Clubmans
Kit can be used. These are restricted to the
following parts:
Body Strengthening Kit
Fuel tank Guard
Strut brace (tube), Strutbrace brackets LH/RH
Roll cage assembly
Rear beam bushes
Rear road springs
Rear shock absorbers
Engine mounting rubbers (set of 3)
Download PDF