Have been searching through old posts and to summarise it would appear that power gains can be had from Head & Cam work although from what I read Cam swaps arent recommended.
EFJIE a french company at some point did a 198bhp tuning pack for the 172 (Clio RS in France) which involved the following modifications:
Fast race cams (it now revs to 8000!), Gas flowed head, engine management reprogrammed (NOT CHIPPED THIS IS THE CORRECT WAY TO DO IT - ON A ROLLING ROAD, EFJIE HAVE PERMISSION FROM RENAULT TO RE-MAP YOUR ECU -LIKE PRODRIVE).
It also came with a Full Devil exhaust system. No induction kit is used, just a replacement green air filter.
As for handling, its new Blistein all round.
Apparently a review of the conversion describe the car as even more frantic to drive. It does lose some low end torque though which can be expected. Here are the figures-
0-100kmh 6.7sec, Max 215kmh, 0-1000m 27.5sec, 0-400m 15sec, 80-120kmh in 5th 14.1sec (2.2sec slower than normal), 50-150kmh in 5th 27.8 sec (2.8sec slower than normal).
It would appear that TechnoMap another french company provide modified heads and cams also. They take original 172 cams and modify them.
Apparently 5 BHP extra for the head work and 7 BHP extra for the cams.
Apparently the 172 cams are very particular , they are hollow , made in a VERY VERY hard metal , and they are already very radical to start with. Changing them is supposed to make the car very undriveable.
