What do standard GTI's normally make on a RR?

[FamilyDub]

^^^ ClioSport/Renaults are quoted in metric PS, not bhp, but even allowing that, it should only account for +/- 5bhp of a difference.

[Saint Steve]

n/a cars commonly make less than normal.  pretty much most turbo cars make the correct figures on a reliable dyno.  Although f you want to get some free Hp i hear superchips dyno gives them away in doggy bags

Yes mine gave 255bhp on my stock Ed30 back in the day  , on their well set up Rolling road .