Homologation paper no 649

Permitted modifications supported by documented evidence.


4 In line. 2279cc.  97.59mm Bore 76.2mm Stroke

The use of a 2609cc engine is permitted.
This uses the same bore size of 97.59mm with an increased cankshaft stroke of 87.20mm.

16V Twin overhead belt driven camshaft’s running in a housing on the head.

The single cam 2300 cylinder head and ancillaries as an alternative to the 16v cylinder head.may be used providing the vehicle otherwise complies with FIA homologation form number 649.

Dry sump lubrication system is permitted.


Lumenition Optical trigger electronic ignition is permitted.

Carburation/Fuel system

Twin 45/48 Weber or Delorto DCOE carburetors.


5speed ZF or 5 speed Getrag

Triple plate clutch assembly

The fitting of a concentric clutch slave cylinder assembly is not permitted.

Back Axle.

Plated LSD.  An axle strengthening bracket is permitted.

Ratio’s. 3.09, 3.45, 3.70, 3.77, 3.90, 4.11, 4.27, 4.55, 4.62, 4.89, 5.13, 5.28, 5.38, 5.8.



Strengthened suspension arms, alloy hub assembly.


Strengthened suspension lower arms and links.


The fitting of a dual master cylinder or any other type of device providing a simultaneous action on all four wheels and divided action on two wheels is permitted providing the original brake pedal and pivot point are used.

The remote brake bias adjuster must be positioned so that it cannot be adjusted by either the driver or co-driver when normally seated in the car.

The fiiting of a hydraulic handbrake is permitted.

Front Brakes.

AP 4 Piston Alloy calipers

Vented front brake discs fitted on alloy hubs.
265 x 21 or 25.4 mm Brake Disc Thickness

Rear Brakes. 

AP 2 Piston brake callipers.
Solid or Vented Rear brake discs
265mm Diameter x 11 or 21 mmBrake Disc thickness

Wheels and Tyres.

Wheel rims, tyre size and aspect ratio as per MSA Blue book.


Fibre glass bonnet and boot lid.
Composite side windows.
GRP front and rear bumpers.
Alloy centrally mounted replacement petrol tank.
Digital display dashes and instruments are not permitted.