I currently have a 60mm greddy catback exhuast on my 99 GSR. I'm looking into getting a header and cat for the car. I'm really not gonna do much past i/h/e/c in teh go fast department for a while. I was the best bang right now. Would I be better off getting the jdm itr 4-1 w/ 2.5 carsound and then downstep to the 60mm catback, or buying a comptech 4-2-1 w/ 2.25 carsound? It seems like if I went the comptech route I would have more usuable, daily, low rpm power. While, the jdm might have a little more power on the top end. Would it really screw things up downstepping from the 2.5 to 2.36?

I really like the jdm itr 4-1 because ive heard great things about it, it's cheaper than comptech(with skidplate), and it's jdm y0. Let me know what ya'll would go for.

 

either set up is fine... comptech will probably have better numbers because i heard there whole setup runs well together ... I would do the comptech but its up 2 you either way

 

The cheapest I have seen the comptech go for is like $420. Can anyyone get it for 400 or cheaper? Otherwise I will prob just go jdm 4-1.