George - Prima arent exactly renowned. I think youll find it hard to pin anyone down whos had work done there and been over the moon about it. Or come to think of it anyone whos had work done there at all. Theyre just not a current player in the world of Clios. To get a standard 1764 valver engine to knock out 200bhp is a hell of a job and would require a lot of work and some wacko race cams. Kent themselves certainly wouldnt quote you 200bhp from any of their cams, let alone the fast road ones which are fairly mild.
As far as turbocharging a valver goes, Im not going to get into the same dull old arguments from people who think that by driving a turbo youre suddenly going to go into a ditch every time you put your foot down in a corner, or who moan about wheelspin. Who cares about wheelspin? So what! Its like going flat out on the motorway at 130 then complaining because you only did 10mpg. If you have a fast car, you have to live with wheelspin, and that goes just the same for RWD as well, its just that their easier to get off the line.
Best bet is to drive a BB demonstrator and see what you think, decide for yourself. My personal opinion is that the best bang per buck is with a low-boost valver conversion, which I can assure you will be plenty fast enough to leave them all standing - while theyre all whining about wheelspin, gearboxes and supposed turbo lag, youll have shown them a clean pair of heels. BTW, if wheelspin is such a problem then how come in my 11 year old valver, on low profile 17" road tyres, with no traction control, launch control or anything of that sort, I clocked a 0-60 in 5.57? In that same properly timed session at Donny South my worst run was only 5.8 or so!