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After the IVA test

The IVA regulations meant that there were a number of aspects of the build that were constrained by having to pass the test. Having now completed the IVA process there was an opportunity to modify a number of aspects of the car in a way that could personalise the build whilst still remaining road legal

Performance Camshaft

I used to have a Lotus Exige S1. It had a 190 BHP version of the VHPD Rover K-Series engine. It was a great car and one of the things I most fondly remembered about it was the throbbing, lumpy, race car-like noise it made at idle due to the slightly wilder cam profile the engine had compared to the lower performance derivatives. I wanted my Stratos to have that so that meant thinking about changing the camshaft profiles on my Alfa engine.

There were various options and specs for re profiling the cams but in the end I settled on the Fast Road profile from AH Motorsport with a potential 30-35 BHP increase standard and would guarantee that race car like lumpy idle. Vernier pulleys were also fitted.

Group 4 Exhaust

For the IVA test the car had to pass noise and emissions regulations. For the test it was fitted with a standard exhaust system with catalytic converters and large silencers.

The plan was always for the car to run with a custom full decat stainless steel exhaust system with minimal silencing. The system was fabricated in the manner of the original Group 4 design for the Dino engine and was retrofitted after the IVA test.

From the Zircotec site:

Primary Black™ is a ceramic coating that retains all of the quality and durability for which Zircotecs coatings are renowned and offers a potential 25% reduction in manifold or exhaust system surface temperatures  based on a typical uncoated temperature of 600oC/1,112oF).


In order to manage heat issues in the engine bay a Davies Craig auxiliary electric water pump was fitted  and both manifolds, connector pipes and silencer tips on the GP4 exhaust were sent to Zircotec to be ceramic coated in the Primary Black colour in keeping with the original cars.

Carbon Airbox

A custom high-flow performance airbox was designed for the engine in the style of the original to protect the ITB’s

A decision was then taken to manufacture the airbox in carbon fiber and a CNC process created a mould for the part.




Lower Fog Lights, Quad Pod and Protective Light Covers

Upper Quad Light Pod and Lower ancillary driving lamps were always part of the full WRC GP4 look for the car. The lower driving lights couldn’t be fitted for the IVA test as they fell foul of the regulations for seeing the front indicators. The regulations also limit the number of main driving lights the car can have so rather than replace 2 of the quad lights with fog lights it was decided to leave the pod off for the test.

ListerBell supplied a regulation protective cover for the quad pod lights. After some research to see what was used in period to protect the lower driving lights a custom pair of Carello Megalux covers were made.

Chin Spoiler

Although differing slightly from the 1/18 scale model I had of the car I was always keen on having the chin spoiler attached to the car which would have been in situ for the tarmac rally stages. ListerBell had previously built a car with one in place and that confirmed to me it was the look I wanted for my car.

Group 4 Rally Dashboard and steering wheel

An IVA friendly dash was fitted for the test which complied with all the regulations along with a soft-touch padded steering wheel. This was replaced after the IVA with a Momo Prototipo wheel from the Heritage range.


A bespoke autoclaved carbon fiber dash was commissioned for the full Group 4 instrument panel and steering wheel.

A mock-up dash was prepared to finalise the measurements before cutting and drilling the final dash.



Dash mock-up

Dash Wiring Completed

Rally Trip Computer

In period, the co-driver side of the dash would have been fitted with Halda Tripmaster rally timers for competition.  I decided that it would be reasonable to fit a modern interpretation of this with one of the latest Brantz digital Rallymaster computers with a GPS derived speed and timing information.

Brantz themselves turned out to be stars by agreeing to modify the wiring of the unit to allow the supply cables to exit at the rear of the computer and remain out of view.


Group 4 Fire Extinguisher

Fire extinguisher fitted into the passenger footwell area.