A 350z with bolt ons. Which will provide the most hp/torque increase? A set of test pipes? or high flow cats? I will have borla headers and true dual exhaust. I dont want to end up having not enough back pressure and loose power/and backfire like crazy.....If I go with the test pipes/ will it make that cheasy popping sound when I let off the gas? If I go with the cats, which are the best for my header/exhaust situation? I was looking at crawford. The have the best price ive seen, but will they produce the gains that others will?

Thanks for your input.

Chris.

 

High Flow cats definitely.

I am an opponent of test pipes due to the annoying buzzing noise they make @ 4K RPMS and when you release the throttle.

The power gains are definitely there with a nice sound increase and it's cheap too, but the raspy sound is not worth it. It makes the car sound cheap IMHO.

Go with high flow cats. IMO they flow just as good as test pipes and do not have the raspy noise.

Victor

 

I second the cats. With your setup I think that is the next logical step. Test pipes will be too loud on your car, IMO. If you dont mind the loudness and the possibility of failing emissions then you can save some money with the test pipes. I dont think there is that much difference in prices of the different replacement cat offerings so the choice is up to you. You will be satisfied either way.

 

I have test pipes. Love the performance. Hate the way they smell and sound. It's a trade-off, I guess.

 

I have Borla headers and true dual.

I think the cat pipes is the final link to complete the awesome exhaust for the reasons stated above. Driving away from the install shop the TQ was immediately noticable and I am very in tune with my car so it wasn't psychological. Cat pipes is what you want (or just cats.) Not dissing the test pipes, I live in California so I would fail emmsions, my cats pass the sniffer and the visual.

 

hehe ... i think i will be going with test pipes myself .... i ve had a car with a test pipe before so im used to the smell and sometimes i actualy think i like the raspy popiness it gives the car,... makes people kinda wonder what the **** is going on under the hood.... ive always been one to sacrifise sound or luxary for that extra 1 or 2 hp.... plus they are cheaper, and ill use the extra cash to make power somewhere else

 

the test pipes are attractive b/c of the price and the gains, but my main concern is failing emissions...i think in the long run its better to go w/the hi-flo cats instead of changing the test pipes for emissions test