hypforlife32

hey guys i have a 2001 ap1. I currentley have an aem v2 intake and 70mm test pipe with stock exhaust. im in debate of trying to stay with the setup i have or ditch the test pipe and go vafc2 and get tuned. the the vafc2 make a good difference in power with cat? or should i stay without? i know the 01's run real rich stock. i just dont feel the need with a 70mm test pipe for 2-3whp hp. any input is helpful right now. thanks.

H22toF20

You should be running a 63.5mm test-pipe with the OEM exhaust not a 70mm. It's to big and will cause a bottle neck where it mates to the OEM exhaust. The right sized test-pipe is the best bang for the buck mod you can do to the S; it's much more than 2-3whp, especially after tuning. A VAFC is nice if you're on a budget and only plan on mild mods; but I would never personally use one.

hypforlife32

i use to have a 70mm single exhaust, thats why its a 70mm.

dan_uk

hey with the stock intake on a 63mm testpipe mine picked up around 2/3HP and about another 3HP with a VAFC tune.


I doesn't seem like a lot but it felt like it openned it up a lot the throttle response with the cat seems better.
You can definitely lean it out with the smaller exhaust piping but once I put 70mm on it was lean enough to where the VAFC no use

I didn't do any VTEC changing.