L86 Headers and cat-back vs stock exhaust

[Carl T]

Yesterday I dynoed a 2016 Denali with an L86 6.2 the following mods:

CJTunes Flex fuel conversion and custom tuning

K&N CAI

Kooks 1 3/4" Catted headers

Gibson Cat-back

 

The truck made solid power at 408whp/461 ft/lbs

 

I had a customer contact me asking about what headers would add to his truck. He has a 2015 Denali L86 6.2 with the following:

CJTunes Flex fuel conversion and custom tuning

Airaid CAI

Stock exhaust

 

The truck made 370whp/432 ft/lbs

 

He was curious what headers would be worth on his truck so I overlaid the two graphs. The header/exhaust truck put down an additional 37.5whp and 29 ft/lbs. The header truck had 51% ethanol content and the manifold truck was around 65% if I recall. I don't think it would make more than a 2-4hp difference but is worth noting.

 

**This is not the same truck but I tuned both and the mods are very similar, I am not claiming this to be a true back to back test but it gives you an idea of gains**

 

 

 

[thetruck454]

Solid gains

[Txjose]

Wonder if 1 7/8 catless would make a difference

 

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[krdeal]

The Kook's headers are definite power producers. I don't think all headers are created equal. I do believe that fuel used provided a few ponies. I do not believe that the 1 7/8" headers would make a huge difference except up top. But drivability suffers a little bit down low most definitely.

[Sooperdave]

Good lawd!!!

[Txjose]

 

 

The Kook's headers are definite power producers. I don't think all headers are created equal. I do believe that fuel used provided a few ponies. I do not believe that the 1 7/8" headers would make a huge difference except up top. But drivability suffers a little bit down low most definitely.

Others beg to differ as well as a few dynos that i have seen. I will learn soon enough as my set of 1 7/8s catless are waiting for me along with a volant catback when i get a chance to go home.

 

Kooks or ARH are top notch. I went ARH because the set i saw had amazing workmanship and a close friend and my tuner recommend them. But kooks are the same thing.

 

 

Just dont get pacesetters..... Rustbuckets lol

 

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[krdeal]

From what I see from ARH, I agree, but I do not have personal experience with them. On a street driven 5.3L motor, I would still go with the 1 3/4" headers again. These things are flowing big time. Pre tune, I am not happy at all with the sluggish performance down low and that's with the 1 3/4" headers! But my Black Bear tune will fix that! Good luck my friend.

[Txjose]

From what I see from ARH, I agree, but I do not have personal experience with them. On a street driven 5.3L motor, I would still go with the 1 3/4" headers again. These things are flowing big time. Pre tune, I am not happy at all with the sluggish performance down low and that's with the 1 3/4" headers! But my Black Bear tune will fix that! Good luck my friend.

Future proof for mild cam and blower is why i went 1 7/8 ;)

 

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[BuyAmericanIron]

Carl T, thanks for posting! Great information. Just installed ARH on mine over the weekend. Can't wait to get it tuned. The quality and resale value are excellent.

[Denali62]

I am running kooks 1 7/8 and ory and it pulls hard to about 6300! When I lug along at 55 in 8th( which is hardly ever!), I do feel a loss in response and an easier to induce downshift. I do not regret the setup at all.

[Txjose]

My installer had a ball with my ARH headers. He said they were flat out the easiest set he has ever installed. Tho all he installs are pacesetter and ebay units so a quality product was a nuce change of pace haha

 

Here is a quick cold start comparison of the volant exhaust. The after does not do it justice at all.... The truck is so much louder in person and you can feel it in your chest when you are that close to it haha

 

 

 

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[07Softail]

Shit that's loud! I think i'm gonna stick with the headers and stock exhaust.

 

RT

[Lgetz]

My installer had a ball with my ARH headers. He said they were flat out the easiest set he has ever installed. Tho all he installs are pacesetter and ebay units so a quality product was a nuce change of pace haha

Here is a quick cold start comparison of the volant exhaust. The after does not do it justice at all.... The truck is so much louder in person and you can feel it in your chest when you are that close to it haha

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TXJ who installed your headers was it done here in RGV?

[Txjose]

TXJ who installed your headers was it done here in RGV?

Yup... They were installed by Spikes Performance in Pharr. Also tuned by spike himself.

 

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[Txjose]

Shit that's loud! I think i'm gonna stick with the headers and stock exhaust.

 

RT

Im going in Monday for a 20" magnaflow and a race muffler as a resonator and see what's what with the sound from their.

 

Its crazy and gotten me in trouble twice already. Haha

 

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