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      06-30-2009, 06:11 PM   #23
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Originally Posted by DevJ View Post
How much torque/hp are you gonna gain from running catless rather than with cats?
With a tune I think its around 40/40 at the wheels for most systems.

I have RPis full exhaust, and although the smell never really bothered me, my litmus test to an exhaust are how my female friends felt about it (no offense to the high horsepower and performance loving ladies on here - you all know the type though). The first few hundred miles it was very strong, even with the top down windows up (ok, at times maybe it did bother me as I wondered if I was giving myself CO poisoning). Lets just say I got an earful. But by the thousand mile mark, especially with a tune to refine the fuel/air mix and burning characteristics, even with the top down you can barely catch a whiff of it - and even then its extremely mild and bearable. On a related note the drone also went from car shaking to a mild rumble under load around 1200-1700 RPMs and that was something I didn't like myself and was relieved it went away.

What I am just saying is that most people will find it imperfect but bearable for the performance gains they get. And the yellowish tint you get from the rich exhaust does cause some visible discoloration on both the body, and the exhaust tips themselves. It does come off the body with a mild solvent and on cars with a good layer of wax back there it can be cleaned off with cleaning polish. As far as the tips a good metal polisher gets it right off with a bit of elbow grease.
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      06-30-2009, 06:23 PM   #24

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I have experience running catless exhausts with my old STi and my current Evo and it makes a world of difference as far as power gains.

You just basically have to decide if you are willing to deal with the occasional smell in trade for the extra power, but I can say that I rarely smelled anything inside the cabin even with the windows down.
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      07-01-2009, 12:06 AM   #25
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How harmful would it be for the motor to run catless without a tune over the long term? Aside from check engine lights.

I am installing a pipe with secondary cat delete and, while im leased so I don't care that much, is it a big concern?

I'm just looking for a little sound, I hope I get that.
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      07-04-2009, 01:41 PM   #26
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Smells like a lawn mower in the garage, stains the back of the car and license plate yellow, but gotta love the power!!!

Wife gives me sh_t about it, but what are you gonna do?
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