gus, are they doing a sports exhaust and hi flow catalytic converters as well as that will give you a lot more torque and power on top of the power increase you will be getting from the supercharging?
I have ordered the compressor kit (plus the suspension pack). I'm not really sure if the HP numbers they quote (352 Bhp for the 2008 version) are related to a new J5 (with EVERYTHING applied) or the effects of the compressor addition without anything else.
I hope it's the latter because...
The Ragazzon exhaust is already in place (the oval pipes are an acquired taste, but after some days you cant help but wonder how you cound stand the standard rectagular ones!)
I have also changed the catalytic converter. The main difference is that it comes in one piece (a big one!) instead of the factory-installed two smaller ones. Apparently the cells inside have a much bigger surface, and heat dissipation is improved, among other things. The local Autodelta dude said that it took Autodelta some time to develop it, as they wanetd to test its compatibility with the NA model as well as their compressor conversion.
Well, when I went for the exhaust / cat mod I had no intention to do the compressor conversion, but I'm glad I'm covered anyhow.
My impressions so far (remember, I'm still with the NA car!): The exhaust change makes a bigger difference that the cat change (most obviously). Low end pull is improved quite noticeably and the sound is of course half an octave lower (but not intrusive). The converter..well, I am not sure if the (minor) improvements I noticed are due to some perceptible effect or mere autosuggestion - but just knowing it exists makes your pocket itchy - it worked on mine!
More to come soon