Headers in stock
Purveyor of Common Sense
Joined: Apr 2017
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From: Chicago Suburbs IL
St. Jude Donor '19
Thread Starter
Emerging Vendor
Joined: Feb 2022
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From: Louisiana
Thread Starter
Emerging Vendor
Joined: Feb 2022
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From: Louisiana
Race Director
Joined: Jan 2014
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From: Fulshear, TX
Beware the Kooks & Corsas with their ridiculous neck-down at the outlet flange. You'll be happy with the aFe, I have been, and am at the 2-year mark already!
Le Mans Master
Joined: Oct 2005
Posts: 5,052
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From: Tampa Florida
I myself narrowed the headers down to AFE and ARH. Kooks and Corsa decline to reveal hp performance.....probably because there is none. For Kooks you have to install the cats to see any gains. And that was recommended by Kooks.
Purveyor of Common Sense
Joined: Apr 2017
Posts: 1,166
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From: Chicago Suburbs IL
St. Jude Donor '19
What about Paragons equal length headers? Looks like they give the most increases of about 25rwhp across the entire rev range. ARH’s is mostly just midrange.
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Le Mans Master
Joined: Oct 2005
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From: Tampa Florida
Race Director
Joined: Jan 2014
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From: Fulshear, TX
For comparison, aFe matches the stock cats perfectly at 2.75" ID while ARH is slightly enlarged at 2.875" ID.
Purveyor of Common Sense
Joined: Apr 2017
Posts: 1,166
Likes: 628
From: Chicago Suburbs IL
St. Jude Donor '19
Paragon advertises a 2.5" ID outlet flange, while the stock cats have a 2.75" ID inlet flange. Just something to keep in mine... Zero clue why Paragon/Kooks/Corsa are doing this when its proven to restrict flow.
For comparison, aFe matches the stock cats perfectly at 2.75" ID while ARH is slightly enlarged at 2.875" ID.
For comparison, aFe matches the stock cats perfectly at 2.75" ID while ARH is slightly enlarged at 2.875" ID.
Burning Brakes
Joined: May 2014
Posts: 1,035
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From: Cape Coral, FL
I am somewhat puzzled by the guys that continue to talk about adding headers when Cordess says "don't waste your money as headers adds nothing". He sells them at his shop. Are you saying he doesn't know what he is talking about?
Race Director
Joined: Jan 2014
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From: Fulshear, TX
Results will vary as there are a ton of variables, but I've done all my bolt-ons strategically one-by-one (with the exception of the ported TB/IM combo), and headers resulted in the largest impact. There are plenty of shops showing strong gains with with headers alone, or headers + cats. Results definitely vary by brand though, specifically with the Kooks/Corsa/Lingenfelter headers and their neckdown to only 2.25" ID at the outlet flange!
Burning Brakes
Joined: May 2014
Posts: 1,035
Likes: 580
From: Cape Coral, FL
Not trying to be argumentative, but was the "largest impact" on a C8 or prior generations? I have seen great gains on C5, C6 and C7 but the manifold on a C8 looks pretty much like a header already. I honestly don't l know one way or the other.
Race Director
Joined: Jan 2014
Posts: 10,709
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From: Fulshear, TX
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
On my C7... Tune clearly #1. After that, probably the ported & coated exhaust manifolds, aFe downpipes, and Borla catless X-pipe. I didn't do full headers on my C7 due to heat concerns with how tight that packaging was.