More On The Engine

To give some background detail on the decision on the choices behind the engine spec I'll do a quick overview on it.

The bulk of modifications will be to the inlet manifold and cylinder head. The inlet manifold will be CNC machined to ensure as good as possible a match between the two cast halves of the manifold and the cylinder head. The lower section of the manifold will also be machined with o-ring grooves in order to improve sealing and minimise any steps between cast components as well as to allow quick disassembly for access to the plugs and leads without having to bother about gaskets.

The cylinder head will retain standard valve sizes and ports but have a custom valve seat profile cut to aid flow.

The cams will be off the shelf Cat Cams items, I've used Cat previously with good results and have been very happy with the quality of their kit. They are also the cam supplier for the BPM Super Endurance 197's. At the moment the profile may change - 281's are considered the most you can run on standard management/induction setup due to any greater overlap causing the map sensor signal to degrade to the point where the ECU has issues running the engine - however a sneaky secondary map sensor plenum with a restrictor in it may solve this. On to finalise!

Induction/Filtration will be via an ITG AB 80 WTCC spec airbox/filter fed from the front bumpeer and mounted in place of the battery with the ECU moved to sit flat on the battery tray. A Varley Red Top will go in the boot in place of the standard tool kit.

Exhaust will be off the shelf K-Tec stealth as there is realisticaly no benefit from having one exiting through the bumper. The Cat will find a new home in the workshop racking for MOT use only ;-)

Engine Calibration will be a job for Paul at RS Tuning, Paul has mapped a huge amount of Clio's and rather usefully has an emulator which will allow us to live map the ECU on his DD Rolling Road.

Plugs, leads, head gasket and misc bits will all be standard Renault spec. Bottom end bearings will be refreshed as a matter of course and new timing and aux belts/tensioners/rollers will be fitted to ensure the valves and pistons keep out of each others way. A set of ARP big end cap bolts will make sure it all stays in place at 7800RPM - I've used these in F4R 830 race engines and they are now standard fit in the Oreca built 830 Clio Cup engines.

That lot should give over 200bhp at the fly based on previous experience with F4R 730 and 830 engine packages in the race cars.