if your on a tight budget, do this, buy an Evo 6 intercooler a bargain at £200, loads of evo guy are getting rid of the std unit in favout of the larger pace developed one...its one of the best production intercoolers out there......and then use a 1.6 or 1.9 mm head gasket £65, which is safer that machining off the tops of your pistonswhich will weaken them.....or buy proper low comp ones a bit price though....
Originally posted by James Watson Thing about engine mods, do I need to lower compression ratio before any are done or will I be stuck with 98 octane fuel??
It depends if you are willing to forego the manufacturer's safety margins.
If you'd like to keep them, then you could run a couple of psi extra by using fresh optimax or thereabouts
If you fit a FMIC, then you can run a couple psi more.
From that point onwards, you either need to lower the comp ratio, or fit Water injection - or else the safety margins shrink.
You'd also need to ensure that the fuelling is behaving itself at the increased boosts.
Of course the turbo itself will be spinning beyond it's intented range, so it's life will be shortened anyway.