Postby 93_Clubman » Sun Aug 29, 2010 1:34 pm
Worthwhile increase in engine performance, but also if you use the CAI that breathes throught the cowl area below the winscreen (next to the fresh air intake for cabin), then yes there is a noticeable increase in noise.
CAI or at least opening up breathing along with high flow catalytic convertor & cat-back exhaust is a very well trodden path on these & many vehicles. Next is usually better headers, although hard to improve on NB8, but NA6 from memory can be improved upon, & there's a little room for improvement on the NA8. Next it's usually a piggyback or standalone ECU, depending on which State etc you're in.
In terms of how much of an increase in performance you can expect on an NA6 with CAI & full exhaust from engine to rear bar, from memory no more than 10kw, & that's assuming a full & recent service to ensure already optimal engine performance. I'm sure that NA6 owners that have done this can better advise. Btw, increasing the timing on the NA6 from 10 to 14 degrees is also popular.