Im stuck with the spi and Ive got a short air intake and full cat back exhaust, but of course I want more.. I was wondering if anyone has the FC 4-2-1 race header on their spi? if so, does it make the spi much much louder and does it really gain enough for the cash? I know it deletes the cat and emissions isnt checked where I live, Im lucky I guess.. but also would just getting the shorty header be better? yeah..

it will be much louder...and the power is certainly worth the cash. you spent what...300+ on a cat-back for 3whp...why not spend a little more for tripple the gain. specially if emissions are not checked.

Or if you have access to a welder and a decent shop, you can take an Escort GT header and with a little work you have a nice 4-2-1, no cat, and a really sweet sound.

I did mine in a matter of hours. You will have to sacrifice your cat bend to connect to the flexpipe, unless you're in good with a muffler shop. You can get a stock header for less than $50.