what gains?

**jiveass** · 02-21-2011, 04:40 AM

i noticed a little more power on the top end when i installed the headers....anyone know what kinda gains you get from lt's when your car is not tuned? and how much of a gain after its tuned>?

**Knight** · 02-21-2011, 04:45 AM

It's going to depend on if other mods are done - ie. heads, cam, intake, ect.

**jiveass** · 02-21-2011, 04:48 AM

i have no other mods.....not even a lid...just headers...3" ory....flowmaster......egr delete...im just tryin to get an idea of what can be had after a tune...

**Knight** · 02-21-2011, 04:52 AM

I'd guess, if you've never had a tune before, around 10 to 20 give or take. A good tuner will be able to gain more power with just a stock ls1. Add a better flowing exhaust, as you have, and the gains increase.

**Sarge** · 02-21-2011, 05:30 AM

A tune on your setup will net you about 10% more power.

**Sid447** · 02-24-2011, 09:59 AM

They ran a headers test,

in Australia some years ago now (2003-2004) testing 20 different aftermarket headers onto a stock LS1 which baselined at 347hp/349tq on an engine dyno.

The best of them gained 10-12hp/10-12tq over the stock manifolds.

**Spaz** · 02-24-2011, 12:09 PM

you'll gain maybe 3 more HP with a tune after the headers if you have a pre exsisting tune...

**jiveass** · 02-24-2011, 12:12 PM

i have stock tune as of now....

***SMWS6TA*** · 02-24-2011, 12:29 PM

According to my butt dyno, the biggest increase of Hp I felt was when I did LTs. Everything else has not been the same noticeable difference.

**karpetcm** · 02-24-2011, 02:07 PM

My own actuall experience, i pulled 336 rwhp without LT's. After i installed the LT's, Ory, SSRA and got a Tune for the headers i pulled 350 rwhp. Ofcourse it was done on different days with different temps but i thought i would gain atleast 18-20 rwhp but in the end i wasnt suprised either. Torque was a 2 rwtq gain as well.

**Y2KPewterSS** · 02-24-2011, 06:23 PM

Originally Posted by Sarge

A tune on your setup will net you about 10% more power.

Most LS1s with headers dyno around 340-350, so 10% would come to 34 or 35 more HP, which is not happening

More like a 3-4% gain from a tune on an LS1 with headers.

**Smittro** · 02-24-2011, 07:18 PM

Originally Posted by Y2KPewterSS

Most LS1s with headers dyno around 340-350, so 10% would come to 34 or 35 more HP, which is not happening

More like a 3-4% gain from a tune on an LS1 with headers.

Wow, I would've thought much more than 3-4%..

Headers made a big difference in the old days..

**Y2KPewterSS** · 02-24-2011, 07:27 PM

Originally Posted by Smittro

Wow, I would've thought much more than 3-4%..

Headers made a big difference in the old days..

My math was based on the tuning aspect of an LS1 with headers. I would say on average, you are looking at a 20 HP gain by adding long tubes to an LS1, which usually gets them into the 340-350HP range. Unless I read Sarge's comment incorrectly, he was saying you can add an additional 10% to that with tuning. 10% of that would be 34-35HP which we all know an LS1 with headers and tuning is not going to be putting down 380s, you need a cam for that. Maybe Sarge meant 10 additional HP(not percent) with tuning on top of headers.

**Smittro** · 02-24-2011, 07:47 PM

Originally Posted by Y2KPewterSS

My math was based on the tuning aspect of an LS1 with headers. I would say on average, you are looking at a 20 HP gain by adding long tubes to an LS1, which usually gets them into the 340-350HP range. Unless I read Sarge's comment incorrectly, he was saying you can add an additional 10% to that with tuning. 10% of that would be 34-35HP which we all know an LS1 with headers and tuning is not going to be putting down 380s, you need a cam for that. Maybe Sarge meant 10 additional HP(not percent) with tuning on top of headers.

Well you guys know best..

I guess I was more curious and surprised by 3-4%..

**Mike0202** · 02-28-2011, 10:23 PM

Originally Posted by karpetcm

My own actuall experience, i pulled 336 rwhp without LT's. After i installed the LT's, Ory, SSRA and got a Tune for the headers i pulled 350 rwhp. Ofcourse it was done on different days with different temps but i thought i would gain atleast 18-20 rwhp but in the end i wasnt suprised either. Torque was a 2 rwtq gain as well.

I was curious. Did you dyno those numbers with LT's and the stock cat back with a hooker muffler and a cut out? Or do you have a full 3" cat back? Sorry if I missed something, its late

OP- Alot of the gains from headers come from the new 3" Y pipe as well. I would say 20 without the tune is a safe bet and another 5-10 after the tune.

**0rion** · 02-28-2011, 10:28 PM

another thing you have to factor in is power down low and throttle response. Both of which gain a lot with tuning. This is why I hate dyno racing. The dyno doesn't tell the whole story here. Headers and no tune and you could actually run slower 1320's than the stock manifolds. Not saying that's the truth for all cars but it's a possibility.

**importhater81** · 03-01-2011, 02:26 AM

Originally Posted by jiveass

i noticed a little more power on the top end when i installed the headers....anyone know what kinda gains you get from lt's when your car is not tuned? and how much of a gain after its tuned>?

LT's were good for 3 tenths off my e.t untuned,and another 2 tenths once tuned.

I went from 13.3e.t. with stock manifolds to a 12.8 with LT's and a mail order tune from Frost.

**jiveass** · 03-01-2011, 04:49 AM

Originally Posted by importhater81

LT's were good for 3 tenths off my e.t untuned,and another 2 tenths once tuned.

I went from 13.3e.t. with stock manifolds to a 12.8 with LT's and a mail order tune from Frost.

i hope i see the 12s with a tune...

**karpetcm** · 03-02-2011, 10:28 AM

Originally Posted by Mike0202

I was curious. Did you dyno those numbers with LT's and the stock cat back with a hooker muffler and a cut out? Or do you have a full 3" cat back? Sorry if I missed something, its late

OP- Alot of the gains from headers come from the new 3" Y pipe as well. I would say 20 without the tune is a safe bet and another 5-10 after the tune.

The only difference between the first dyno and second was on the second dyno i had installed LT, ORY, Re Tune and SSRA(which wont help much on the dyno anyway,ssra). I dont have a catback exhuast just the hooker muffler with the exhaust cut out right before it goes over the axle.

**Firebirdjones** · 03-02-2011, 02:19 PM

Originally Posted by importhater81

LT's were good for 3 tenths off my e.t untuned,and another 2 tenths once tuned.

I went from 13.3e.t. with stock manifolds to a 12.8 with LT's and a mail order tune from Frost.

I'd say that's huge and probably out of the ordinary, especially for an 02 that has the better manifolds to start with. The problem with the track time comparison,,,,you have to keep track of DA numbers to be accurate.

On my 02 SS, installing long tube headers and an off road Y pipe, while still running the factory 3" optional SLP dual/dual CME,,,,,I only picked up about a tenth and roughly 1.5 mph. The DA was only 200 ft. difference.
That was after I tuned it and dialed in the WOT AFR.
Just not really that much of a gain at the track for me. Honestly the gains I saw at the track run just about in line with the HP increases that everyone else is posting they've seen on the dyno.

Just shows that the stock manifolds aren't that bad (actually pretty good pieces) if the rest of the engine is stock. The truck manifolds I'm messing with on a 6.0 swap right now look pretty damn good for a manifold, so they are staying.