so lets say u bolt on some jenveys with omex or gen90 and have it mapped, no other real mods other than exhaust, will you see a genuine 30bhp gain? i think if i was going down this route id get some 421 cams fitted as well for larger gains. or am i talking nonsense.![]()
You should see in the region of 30bhp yes, and with cams as well that will be more like 40.
But bear in mind that the standard internals are a lottery at high rpm, the rod bolts and valves can both potentially fail, and hotter cams means more time spent further up the rev range.
Power wise a turbo conversion offers MUCH better gains of course, but also offers increased maintaince potential with the turbo itself, and some people prefer the way N/A cars drive on track by so much that they are happy to take the power hit.