[Redline_2ss]

can you guys do me a favor? Post your dyno sheets for gains from installing LT headers. Just ordered some and started looking through here and see lots of confusion. Some people claiming 35whp which sounds like too much and others saying only 10whp which is not worth it.

Thanks ahead of time

[Jaxcam02]

don't have dyno numbers but I don't think headers by themselves are going to do much of anything, especially without a tune.

[Redline_2ss]

I have some bolt ons and e85.
Asking for dyno sheets or just gains in general


side note: running headers without a tune is kinda wild to me. would run rough

[BigGuy81]

The way I see it, there are few numbers to look at vs. stock.

1. Headers-only (though you'll need to disable rear O2's if catless)
2. Tune only
3. Headers+tune

Most of the time people post dynos following a LTH install with a tune included, so it's not a really good indicator of the performance gains.

I'd also like to see a comparison with primary cat deletes.

[s346k]

Originally Posted by Redline_2ss

side note: running headers without a tune is kinda wild to me. would run rough

this is not an accurate statement. i drove my car several hundred miles on the stock tune with headers and no cats. it did not run rough or suffer otherwise. i know of a car with kooks headers (and cats) & cai on the stock tune. runs perfectly fine and has for 15k? miles. the car is no faster than stock, but also no slower and no ill effects.

i highly suggest ethanol and a tune with headers, otherwise one is simply throwing money away.

i did full exhaust, no cats and ethanol. stock tb and airbox. no baseline dyno but the car noticeably picked up. educated guess - around 6 mph. whatever that translates to on a dyno. ill hit a track up soon to verify. it’s an 18 1LE, still full weight.

[asthmamax11]

Jannety posted a bunch of before and after dynos for almost all the bolt on mods about 3 years ago

[wnta1ss]

Originally Posted by asthmamax11

Jannety posted a bunch of before and after dynos for almost all the bolt on mods about 3 years ago

As I recall, one of his cars picked up about 20hp with ARH headers and high flow cats. Another car got about 15hp with ARH long tubes and high flow cats.

Think some members have posted their Kooks headers with high flow cats before and had reported about 21 to 25 hp gains.

Have not seen any data on the race car setup (completely catless).

As for just cat deletes, one test showed nothing without tuning, but after he tuned, he had gained about 10 or 11 hp, those were primary cat deletes, so he still had the secondary cats in place.

Also I agree with Redline_2ss that installing headers but not tuning for them does not make a lot of sense. Seems to me that, if you just want noise, you could just do a muffler delete or something to make it loud.

[Umbriel]

No dyno sheet but my baseline was 388 rwhp and after headers, E85, Rotofab and tune it was 432 rwhp.

[7speed]

Guy on youtube just got kooks headers and green cats and dynoed his otherwise stock C8 Vette and only gained like 5hp and 8tq. They claimed 20, he is disappointed but he likes the sound at least.

As far as Camaro I wouldn't get headers as my only mod since your not trying to tune. If you are trying to keep warranty you probably get at least same amount of gains for less money by ported tb or 95 tb, ported stock intake mani and rotofab.

[RyanR623]

Originally Posted by 7speed

Guy on youtube just got kooks headers and green cats and dynoed his otherwise stock C8 Vette and only gained like 5hp and 8tq. They claimed 20, he is disappointed but he likes the sound at least.

As far as Camaro I wouldn't get headers as my only mod since your not trying to tune. If you are trying to keep warranty you probably get at least same amount of gains for less money by ported tb or 95 tb, ported stock intake mani and rotofab.

Agreed. The tri-Y design is very good on these cars. Would be cheaper getting primary cat delete pipes and having it tuned. If you don't mind it on the loud side.

[Redline_2ss]

headers isnt the only mod I have. Currently have other bolt ons and e85. Just want the car a little louder and gain more powah baby. Was just curious as to what people were really gaining since some people were saying 10 which didnt sound like enough to me and others were saying 50 which is too much. I'll be happy with like 25-30 RWHP gain.

[7speed]

Originally Posted by Redline_2ss

headers isnt the only mod I have. Currently have other bolt ons and e85. Just want the car a little louder and gain more powah baby. Was just curious as to what people were really gaining since some people were saying 10 which didnt sound like enough to me and others were saying 50 which is too much. I'll be happy with like 25-30 RWHP gain.

Well damn, I might have you mixed up with another post I saw.

Shiiiiiet, go ahead then, probably 10-15 gain with retune would be my guess.

[Jhunsberger]

Here is my dyno sheet, mind you I have a Whipple setup. There are a couple variables here, but considering the changes, to me it wasn't worth the investment in parts, good thing I installed myself.

Before:
Cat delete pipes
Boral ATAK full exhaust
Stock TB
Standard Roto-FAB DRY

After:
Kooks 2" catless
Borla ATAK full exhaust
NW 103 TB
Big Gulp Dry

Gain = 33.71/23.51 by adding Kooks 2", NW 103 TB & Big Gulp

[BlackKnight2SS18]

Originally Posted by Jhunsberger

Here is my dyno sheet, mind you I have a Whipple setup. There are a couple variables here, but considering the changes, to me it wasn't worth the investment in parts, good thing I installed myself.

Before:
Cat delete pipes
Boral ATAK full exhaust
Stock TB
Standard Roto-FAB DRY

After:
Kooks 2" catless
Borla ATAK full exhaust
NW 103 TB
Big Gulp Dry

Gain = 33.71/23.51 by adding Kooks 2", NW 103 TB & Big Gulp

That's a chunk of $$$ for 33 HP. And you've got a blower.

I'd be surprised at anything more than 10-15 HP on a NA setup.