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Exhaust and low end power? Dynos?

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Old Feb 19, 2012 | 05:42 PM
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Default Exhaust and low end power? Dynos?

Well I want to start off saying I want a new exhaust. I am currently looking into Tanabe because it is not super loud, and usually axle backs dont hurt power. But I can sacrifice sound for power, but I will not settle with killing my low end. There is a user on here with the Greddy, also Dsport magazine put the Greddy on their 2012 TC project car. Both the users, and Dsports Dyno graphs show no loss in low end power. Can anyone confirm this with other exhausts? Any body else have Dyno graphs?
Old Feb 19, 2012 | 07:20 PM
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I can confirm a loss in low-end power with the Tsudo.

Users of Descendant and GReddy, however, say they experience no loss from the bottom-end.

I sold my Tsudo and now have the TRD exhaust. I experienced no loss. I'd say most axlebacks will not cause loss since there is no change in pipe diameter.
Old Feb 19, 2012 | 08:21 PM
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with descendant I did lose some low end but not as much as tsudo it seems
Old Feb 19, 2012 | 08:31 PM
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with any exhaust you loose some low end...if you think about the whole point is to allow the car to breathe better,so this way when your car gets to the mid to upper power range,thats when you really feel it,depending on your mods...
Old Feb 19, 2012 | 08:46 PM
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I agree and understand that to be true but the last time I argued that, someone threw bogus dyno results in my face. Just going with the flow now lol.
Old Feb 19, 2012 | 10:46 PM
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dynos to me really doesnt prove much,its the way the car responds and acts that make the difference...
Old Feb 20, 2012 | 01:41 AM
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More flow = lost of low end torque but more high end power.
Old Feb 20, 2012 | 01:48 AM
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Well, its not that any aftermarket exhaust decreases low end power, it depends on pipe diameter and quality. The reason you get a decrease in low end power is from a pipe diameter too large for our N/A set up that doesnt give enough back pressure in low RPMs. The perfect exhaust will be at a diameter to promote as much free flow as possible, while still giving adequate back pressure. Also with very few harsh bends, and as straight as possible.
Old Feb 20, 2012 | 01:59 AM
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Originally Posted by biglilsteve
I can confirm a loss in low-end power with the Tsudo.

Users of Descendant and GReddy, however, say they experience no loss from the bottom-end.

I sold my Tsudo and now have the TRD exhaust. I experienced no loss. I'd say most axlebacks will not cause loss since there is no change in pipe diameter.
Biglilsteve is the TRD exhaust a axle back only.
Old Feb 20, 2012 | 02:06 AM
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Originally Posted by ERZperformance
More flow = lost of low end torque but more high end power.
That's pretty much the bottom line when it comes to exhausts. You can try and get all technical with it about bends and quality of materials, but at the end of the day...

2.5" Catback exhaust = Decreased low end, Increased mid and high end
Old Feb 20, 2012 | 02:08 AM
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Originally Posted by ERZperformance
Biglilsteve is the TRD exhaust a axle back only.
Yup that's correct. Its only a bolt on replacement for the rear muffler section.
Old Feb 20, 2012 | 02:13 AM
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Dynos are good from the perspective of change from baseline. Dyno could say the tC has 50 WHP stock or 350. Doesn't matter. All that matters is you use the same Dyno in similar conditions and compare the difference.

Anyway... I didn't notice any power loss at low RPMs, and while accelerating, I stay between 2500 and 3200 rpm generally.

But it's just my perception. Others will have their own
Old Feb 20, 2012 | 03:38 AM
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Originally Posted by biglilsteve
I agree and understand that to be true but the last time I argued that, someone threw bogus dyno results in my face. Just going with the flow now lol.
There is nothing bogus on the dyno results, and if you prefer your understanding versus real facts it's your call Sir.

Originally Posted by my06tc
dynos to me really doesnt prove much,its the way the car responds and acts that make the difference...
My I ask you, why do you think dynos exist, and why people use it for, and how you quantify your gains, and how you tune your performance mods if you do any?

Originally Posted by ERZperformance
More flow = lost of low end torque but more high end power.
Your results may vary.

Originally Posted by noskatehate22
Well, its not that any aftermarket exhaust decreases low end power, it depends on pipe diameter and quality. The reason you get a decrease in low end power is from a pipe diameter too large for our N/A set up that doesnt give enough back pressure in low RPMs. The perfect exhaust will be at a diameter to promote as much free flow as possible, while still giving adequate back pressure. Also with very few harsh bends, and as straight as possible.
Right on!
Having said that my exhaust is ready for Turbo, if it is 2.5 inches diameter the results will be better.

Originally Posted by ProjectTC2
That's pretty much the bottom line when it comes to exhausts. You can try and get all technical with it about bends and quality of materials, but at the end of the day...

2.5" Catback exhaust = Decreased low end, Increased mid and high end
I beg to differ with you Sir!

Originally Posted by MightyP
Dynos are good from the perspective of change from baseline. Dyno could say the tC has 50 WHP stock or 350. Doesn't matter. All that matters is you use the same Dyno in similar conditions and compare the difference.

Anyway... I didn't notice any power loss at low RPMs, and while accelerating, I stay between 2500 and 3200 rpm generally.

But it's just my perception. Others will have their own
Finally somebody that it knows what we are talking about it. I can't say better than that.

Last edited by 1087; Feb 20, 2012 at 04:21 AM.
Old Feb 20, 2012 | 04:15 AM
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also depends on what gear box you got. I have auto and felt low torque come back when I reinstalled stock exhaust
Old Feb 20, 2012 | 04:40 AM
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Does anybody know what size our stock exhaust is? It seems that something between stock and maybe 2.4 inches is a good compromise. It seems if you go 2.5 and beyond, say buh bye to usable power.

Im not saying exhaust dont take low end power, im saying there is a happy medium, and I'm just trying to find it!!
Old Feb 20, 2012 | 12:59 PM
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I think the stock exhaust is 2" or maybe just very slightly over
Old Feb 20, 2012 | 05:10 PM
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My findings thus far:

Stock: 2" (Estimated)
ARK: 2.5", Cat-Back
Borla: 2.25", Axle-Back, 8hp/12tq
Descendant: 2.5", Cat-Back
Greddy: 2.75", Cat-Back, 4.5hp/3.4tq, 39.8lbs
HKS: 2.36"-2.95" (Tapers), Axle-Back
Injen: 2.36", Axle-Back, 6hp/7tq
Magnaflow: 2.25", Axle-Back, 6-7hp
Tanabe: 2.36", Axle-Back
TRD:??
Tsudo: 2.5"

Last edited by noskatehate22; Feb 21, 2012 at 05:09 PM.
Old Feb 20, 2012 | 05:57 PM
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does axle back exhaust really gain hp/tq?
Old Feb 20, 2012 | 06:18 PM
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Guess I need to measure my stock exhaust tonight...
Old Feb 20, 2012 | 07:38 PM
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paul, you have descendant exhaust right?



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