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Old Mar 11, 2006 | 06:52 PM
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Default Cut-Out?

Alright so I tried doing a little bit of searching but was unable to find any good info about cut-outs. I was mainly wondering if you suffer any loss of HP or torque down low with a cutout on a stock LS1. I decided that a cutout if it is actually performance beneficial would be my best bet as a starting performance mod since Longtubes + Y pipe might cost me a bit too much, especially on the install. So what are average gains for a cut-out on a stock LS1? And where is the best place to put it?
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Old Mar 11, 2006 | 07:00 PM
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Usually about 10 hp sometimes more
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Old Mar 11, 2006 | 07:05 PM
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Best place to put it...on the I pipe just before the rear axle...
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Old Mar 11, 2006 | 07:07 PM
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Wow 10+ HP from a cutout? Not too shabby... Is there any loss of torque due to lost backpressure? Also, isnt there a place that it is "designed" to fit? Like there is a gap somewhere?
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Old Mar 11, 2006 | 07:08 PM
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Originally Posted by Kenafin_02TA
Best place to put it...on the I pipe just before the rear axle...
yes. ..right under the rear passenger seat there is a hollow just made for a cut-out.
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Old Mar 11, 2006 | 07:22 PM
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Originally Posted by then00b
Wow 10+ HP from a cutout? Not too shabby... Is there any loss of torque due to lost backpressure? Also, isnt there a place that it is "designed" to fit? Like there is a gap somewhere?
There might be a little lose down low but it makes up for it up high and it sounds really good on stock manifolds.
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Old Mar 11, 2006 | 09:46 PM
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On my cam only car it was worth 26 hp over the stock exhaust. I put it in the Y pipe just before the axle. It still flows through the high flow cats that came with the Stainless Works headers. Sounds awesome, it's just hard to keep my finger off the button and I'm going to get a ticket someday! Car made 381 at the rear wheels with cutout open, made 355 with it closed. I do not notice any loss of low end torque and the dyno chart would confirm that, it makes more torque from 3500 rpm and up.
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Old Mar 11, 2006 | 10:08 PM
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Stock LS1, ok it sounds nice.

LS1 without cutout= ROAR!

You will notice a loss of torque from a dead stop. I just leave my open all the time, sounds pretty vicious on Longtubes and an offroad Y, cutout just before the muffler.
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Old Mar 12, 2006 | 04:55 PM
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Originally Posted by then00b
Alright so I tried doing a little bit of searching but was unable to find any good info about cut-outs. I was mainly wondering if you suffer any loss of HP or torque down low with a cutout on a stock LS1. I decided that a cutout if it is actually performance beneficial would be my best bet as a starting performance mod since Longtubes + Y pipe might cost me a bit too much, especially on the install. So what are average gains for a cut-out on a stock LS1? And where is the best place to put it?
Got some results for you

https://ls1tech.com/forums/generation-iii-external-engine/468136-track-proven-results-cutout-si-stock-exhaust.html
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