Exhaust cutouts?
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Drifting
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From: Wisconsin
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Exhaust cutouts?
Since my thread on stock big block exhaust manifolds has gotten pretty good I thought I'd like to start even more confrontation.... exhaust cutouts do they...will they effect horsepower?
Le Mans Master
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Le Mans Master
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The cut-outs really increase the horsepower when you are driving under a large interstate bridge- just sayin!!!
My other favorite thing to do- is sitting at a stoplight next to a "newer" corvette- and they don't even acknowledge you when you wave- another appropriate time to open them up!!!
My other favorite thing to do- is sitting at a stoplight next to a "newer" corvette- and they don't even acknowledge you when you wave- another appropriate time to open them up!!!
Instructor
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From: Blue springs mo.
Placement.
On a 79 350 auto long tube headers 2.5” duels no cats. Where would be the optimal placement ???
Thread Starter
Drifting
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From: Wisconsin
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Le Mans Master
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From: Cool Northern Michigan
Absolutely "open" dumps will add horsepower. Any time your remove resistance or restrictions to the exhaust system is a plus.
I have dumps on my '77. And I un-cap on special occasions. I also have a picture of installed placement in my photo album.
Click on my avatar then look for show all albums > untitled album. It's in there somewhere.
A tip on dumps or header collectors is to tack weld the six bolts onto the collector flange. Then when you want to open the headers, you only need one wrench for the nuts.
( bolt can't turn )
I have dumps on my '77. And I un-cap on special occasions. I also have a picture of installed placement in my photo album.
Click on my avatar then look for show all albums > untitled album. It's in there somewhere.
A tip on dumps or header collectors is to tack weld the six bolts onto the collector flange. Then when you want to open the headers, you only need one wrench for the nuts.
( bolt can't turn )
Last edited by HeadsU.P.; Mar 16, 2023 at 08:37 AM.
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Burning Brakes
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I actually tried mine on the dyno and they did improve horsepower.I have headers to cutouts to dyno max single chamber mufflers. Cutouts shut, I have mufflers, cutouts open, it’s just open headers.
I did three dyno pulls, the first two with cutouts shut, the third with cutouts open. Not too surprisingly the third pull had the highest peak hp, a gain of 8hp.
I did three dyno pulls, the first two with cutouts shut, the third with cutouts open. Not too surprisingly the third pull had the highest peak hp, a gain of 8hp.
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Drifting
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