Test Pipe? Yes or No

[frsh13]

My cat converter is completly gone....so a few days ago I installed a test pipe that one of my fellow 240 buddies gave me. I thought the results would be better, no cat to block restriction just straight through. Well after driving around for a few days i think it made my car slower. The throttle also doesnt seem as consistent when im flooring it. It seems the only advantage to the test pipe is at high rpms like at around 5.5 k it pulls harder. So what are your views on the test pipe for an NA 240. Is it worth it? Or did i really make my car slower due to the loss in back pressure? Should i just order a high flow cat?

[574-240sx]

I ran a test pipe on my N/A KA for a while and didn't notice a difference in performance. The only reason why I ran it is because it came free with my catback exhaust. I also had turbo in mind in the near future. If you have emmisions or care about the enviroment it would be your best intrest to get a high flow cat. A high flow cat won't add much back pressure.

[frsh13]

bump for more info/help

[themadscientist]

the complete lack of backpressure can do exactly what you describe. what is in your complete system from head to tailpipe? Include pipe sizes.Anything bigger than 65mm sounds too big, you may have to make a restrictor plate.

[frsh13]

im runnin stock headers > testpipe > 5zigen fireball exhaust.....im pretty sure its 60mm.

And what is a restrictor plate?

[AmoebAssassin]

Think of the birds, run a cat!

[Onizuka]

Running a test pipe on NA KA is totally worthless.

[frsh13]

so should i order a high flow cat, or go pull a semi-decent one from a junkyard 240?

[nismojunkie]

i hollowed out my cat and didnt really notice a diff. except where you mentioned around the upper rpms. but i dont feel like it made it any slower.