Will a cut out hender a LT1?
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Joined: Mar 2005
Posts: 60
From: Noble, OK
Re: Will a cut out hender a LT1?
Originally Posted by madwolf
wow... thanks alot! I'll have to print this list off...
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Joined: Feb 2003
Posts: 1,109
From: Statesville NC
Re: Will a cut out hender a LT1?
Take backpressure completly out of the formula. The most power will be found with the most free flowing, least restrictive setup. No backpressure is what you want. The cut out will do this.. However placment is key. If you do not have the cutout set in the correct spot for the tuned RPM you CAN and WILL hurt your HP. When the exhaust hits the atmosphere there is a reversion wave. The timing that the wave hit's the exhaust valve event is important. If it is highpressure during the event it will hurt the flow. If it is low pressure during the event it will helpp to "pull" the exhaust out of the motor and increese flow.
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Joined: Jul 2001
Posts: 603
From: I-L-L-I-N-O-I-S
Re: Will a cut out hender a LT1?
Originally Posted by HBHRacing
Take backpressure completly out of the formula. The most power will be found with the most free flowing, least restrictive setup. No backpressure is what you want. The cut out will do this.. However placment is key. If you do not have the cutout set in the correct spot for the tuned RPM you CAN and WILL hurt your HP. When the exhaust hits the atmosphere there is a reversion wave. The timing that the wave hit's the exhaust valve event is important. If it is highpressure during the event it will hurt the flow. If it is low pressure during the event it will helpp to "pull" the exhaust out of the motor and increese flow.
And I'd recommend putting the cutout on the section of the I-pipe just before it goes over the axle (you should be OK with it anywhere after the cat/offroad pipe you're running). It is true that some false knock can be picked up if the cutout is too close to the motor...
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Joined: Jul 2001
Posts: 4,577
From: DeKalb, IL
Re: Will a cut out hender a LT1?
From what I've seen specifically with LT1s, it depends a lot on the cam and heads (besides the exhaust system). I am positive my car will not make more power no matter where you installed the cutout. If you would like to prove me wrong, I'd be happy to weld the cutout anywhere you say it will make more power.
The car has Jet-Hot LTs, Hooker Y-pipe, no cats and magnaflow exhaust.
The car has Jet-Hot LTs, Hooker Y-pipe, no cats and magnaflow exhaust.
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Joined: Jul 2005
Posts: 473
From: Munfordville, KY
Re: Will a cut out hender a LT1?
When my car was stock, I gained .1 and 1 MPH. I have mine right in front of the passanger rear tire. I haven't ran my car with the cutout closed dince the cam swap.
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Joined: Feb 2003
Posts: 1,109
From: Statesville NC
Re: Will a cut out hender a LT1?
Originally Posted by madwolf
That's where mine is located.
Thats probably the "best" location to be at. A lot depends on the system that your running. What headers, manifolds, Y pipe, ORP, cats, duals etc etc etc. The "basic best guess" for a cutout is about 30 Inches past the Y pipe. After that you would be looking at several hours of trial and error on a dyno moving inch by inch to find the best power for the correctly RPM tuned placement. If you don't have a cat, put it right at the end of the Y pipe and you should see less power. You also have to remember that if your Y pipe is different size from one side to the other it can really change things.
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