I have a customer with a S2k. He has a kn filter and a mugen test pipe on it rest is stock. He had it dynoed and it made 195 at the wheels. He also went to another dyno day for S2ks and there was another guy there that had a header and catback as well and he only made 196.

My question is what are the worth while mods for the car? IS a VAFC worth it for the car?