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headers vs cutout

733 Views 5 Replies 6 Participants Last post by  Elmer_Fudd
currently my exhaust system is completely stock with the exception that I have a test pipe and cutout avaiable to me. It is already installed, and I can manually unscrew the cap and have my exhaust exiting immediatly after the headers.

I know that using the cutout is extremely loud, i've done it before. Now here is my main question. Which will actually net larger gains? Should I install some ebay headers or should i invest in an electric cutout option where i can change that from inside the car?

headers would gain hp all the time, but i'm not sure. I'll probably stay NA for another year or so, then i'll boost it.

opinions? or should i find a dyno, & dyno it with and without the cutout, look at the gains, then see if headers would gain more. I know headers are good for about 5-10 hp, right?

thank in advance everybody
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a cut out is not where you want to focus, its the exit at the heads.
Running straight open you are likely to loose more HP/TQ across the whole RPM band than you will gain.

In back to back testing running, with Ebay Headers, 2.5" manderel bends, a Magnaflow resonator after the cat, and side exit, the car has MUCH better throttle response and jumps out of corners much more aggressively (more torque) than with a testpipe. The only tangible gains with a TP were above 6krpm increasing with revs, with a severe loss below 5500.

In other words, while the cutout is great for being noisy, it doesn't help you in going fast.

Such is why I still run the stock cat. :)


I have had straight and resonated pipes and stock and high flow cats. I can say that I noticed more power from the high flow cat than either test pipe. The sound is nicer too. This was all on my old motor w/ a cold air intake, hotshot headers, and a borla catback.
cut-outs are best for turbo applications, with N/A a certain amount of backpressure is required so a cut-out might actually underperform a well designed full exhaust
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