+1 for what Mark says.
Having been there, done that I would doubt very much that a simple chip would get you that gain unless you were on a mega-optimistic RR. I suspect that their base care was a good one out of the box & was probably running low 160's anyway, so the chip only gave an extra 10 bhp.
That's what happened with my old 8v - it was running 124bhp before I started (i.e. 9 over book) and that went to 136bhp with the rechip. That was 1998 when AmD was still two blokes in a shed. I ran that just with the rechip for 13 years no
problem until it got scrapped last year.
Moving onto my Cordy, I have Schrick 268 Cams in mine and the garage who fitted them tried to chip it but TBH I don't really think they knew what they were doing. They were more used to dealing with completely standalone engine management systems.
In the end, took it to see Vince @ Stealth Racing on the basis that they seem to be one of the few (or possibly the only) garages who can still be bothered tuning N/A engines. Was about £250 from memory in late 2010.
With a TSR 4-1 manifold, polished & ported head and decat it produced:
Peak power = 182.2bhp @6350rpm
Peak torque = 158.5lb/ft @5775rpm
It currently has a Pipercross Vector induction kit but I'll be putting the original airbox back on in due course. That might improve things slightly as induction kits aren't good ideas unless you're just looking for noise.
