hi, i know there are people who know far more than me here, so im going to pick brains.

Basically, ive done everything on my car myself, and i want to carry on the same vain.

spec so far:

Racing puma fiesta -

1.7 vct zetec-se
2L rebuilt and resprung throttle body
racing puma inlet
2L zetec injectors
port and polished head
racing puma fast road cams
4-2-1 racing puma exhaust with sports cat
and racing puma catback

Run using standard loom and dreamscience to remap my own ecu, which ive done all myself and got it to 174bhp at 8000rpm.

Now ive had fabricated ready a supercharger from a mercedes slk230 which is brand new and with teflon coated blades. Its a roots type supercharger with the electromagnetic clutch system.

Simply put, i was going to ask whether its advisable to lower the compression or not, as the current compression n/a is 10,3:1.

And whether i should do that with pistons or a spacer plate. And if i get pistons, is it a good idea to get to get rods as well. Reason i ask is that the focus st170 powerworks roots type supercharger kit doesnt change compression at all?

hope someone can help