Should I remove the test pipes so I don't lose too much back pressure and lose low end torque???

What are your feelings on this subject??

ANY ADVICE is appreciated!!!

 

keep the test pipes with the headers.

 

wont I lose to much back pressure, causing a decrease in torque???

 

No. You would be negating a big part of the gains if you 86 the test pipes.

 

This depends on how important the whole LOUDNESS issue is to you and what particular combination of components you use. Headers and catback with test pipes can be very loud. Even headers/exhaust with hi-flow cats can be very loud. The COMBINATION of parts can have much a more pleasing results in terms of performance and sound, or it can make your car an unbearable monster to live with....weird vibrations, resonating boominess and drone, or just plain loud.

I have Nismo headers with Jet-hot sterling and Nismo catback with the stock cats still in place. For me sound was a BIG issue, so I really didn't want to change the cats. This particular set-up definitely improves my mid/upper rpm performance with no noticeable change in the lower rpm's. As is, it sounds fantastic. I know I am sacrificing power by not changing the cats, but for me it's not worth the change in sound. You will get a million different opinions on what sounds good/bad etc. and whether or not it is/isn't worth the gains in power.

From what I have heard from others, you may want to consider using at least a good set of hi flow cats. Crawford and UR probably have the "best" sound. Performance gains are similar for all units.

 

Leaving the test pipes on would give you the best gains, but it'll probly be very loud. Unless you don't care about how loud your car is, being legal, and passing emissions then get some hi flow cats.

 

The loudness thing is eniterly a factor of what exhaust you run. I have headers resonated tests and the greddy evo2 exhaust and the exhaust is louder than stock, but not even close to being too loud. Even at WOT, you can still hear the person next to you speaking in the cabin of the car. If I ran the tp and headers with an injen exhaust, I think the consensus is it would be too loud. Heck, I even ran the evo without the mufflers one time and it wasn't too loud (just moving the car into the mddle of the garage while we were working on it)

 

dang, It is pretty dang loud right now (stock headers and exhaust) and I also hate the rasp of the test pipes, so I am leaning towards taking them off and installing the stock CATS. Maybe a high flow CAT would be the best option, I kind of thought this would be my last mod But now I am thinking that Pulleys, Technosquare and high flow cats are all on the list????? WHEN DOES It END??

 

Keep them if you are going to go FI. Maybe look at hi-flow cats or resonated test pipes instead if staying N/A.....will remove the rasp for you and maintain the power