Do LT headers really make that much of difference on a 6.2 torque build?

[73TA]

Do LT headers really make that much of difference on a 6.2? I realize that these trucks, that should be built with torque in mind, not the quarter mile time. I need to replace a lifter in my 6.2 Esky. I was considering installing LT's along with a truck cam during the build.

Will I really gain that much, if it only 10-15 HP or torque in the mid range, not sure if it really worth the hassle, expense and the "maintenance" (exhaust leaks, possible cracking, poor fitment, etc.) of having long tubes.

You may have seen my other post in the general engine section for these EBay headers.

https://www.ebay.com/itm/Chevy-GMC-...Stainless-Steel-Headers-w-Y-Pipe/232936388772


Mike

 

[avalonandl]

No these motors like shorty headers or just use the OE manifolds and put the money into Blackbear tune.

 

[ls1frc]

Of course you'll have gains, it's no different than any other LS engine. Longtube headers will pick up a lot of low to mid range torque. If you look at a dyno graph between long tubes and shorties, the peak power may be close but the mid range is significantly fattened up with longtubes.


Since you're installing a cam, the gain will be even higher. But definitely go with a catted system, you will regret the catless one with a camshaft trust me on that. Also, I'd go with a quality set or stick to stock.

The downsides are:

1) More pronounced engine noise in the cabin
2) Cats won't filter as well
3) Catless with a cam is horrible, don't do it. It not only smells, but if that smell gets near you it will stick to your clothes all day.


If I were you (and didn't want to drop 1600 on catted headers), I'd go with a VVT cam that has a wide int/exh split (at least 12 degrees) and stick with stock exhaust. You'll make another 40-50 hp and the car will drive the same.

 

[73TA]

LS1FRC, that is also one of the questions, to run a VVT cam or not, Don't have DOD so that is not an issue. Don't mind doing the longtubes, going to have the motor out anyway. Definitely not going to spend $1600 on exhaust or for that matter, probably not even $800. Maybe if I wrap the headers it might help keep the cabin quieter.

Still looking for a cam, I will tune from HP Tuners.

Thanks for your input.

Mike

 

[gat0r]

No these motors like shorty headers or just use the OE manifolds and put the money into Blackbear tune.

shorty headers are worthless. (unless you may run turbos)

id either stick w/ stock manifolds or go LT's. if you go LT's, dont mess w/ fleabay ones. at least get speed engineering or texas speed ones.... if not kooks or stainless works.



there are multiple posts here & on other forums, where peeps w/ LTs, CAI, catback & tune on a 6.2 were getting in the 40's range for HP/TQ at peak.

should be in the 20's HP range w/ just LTs. then more w/ tune & more w/ cam

 

[91RS]

Do LT headers really make that much of difference on a 6.2? I realize that these trucks, that should be built with torque in mind, not the quarter mile time. I need to replace a lifter in my 6.2 Esky. I was considering installing LT's along with a truck cam during the build.

Will I really gain that much, if it only 10-15 HP or torque in the mid range, not sure if it really worth the hassle, expense and the "maintenance" (exhaust leaks, possible cracking, poor fitment, etc.) of having long tubes.

You may have seen my other post in the general engine section for these EBay headers.

https://www.ebay.com/itm/Chevy-GMC-...Stainless-Steel-Headers-w-Y-Pipe/232936388772


Mike

Absolutely they do, especially with a cam. The only time you have issues like that is with cheapos. Spend the money and buy ARH headers and you can install them and forget about them. Those headers you linked will likely give you all those problems and might only last a a couple years. You will really limit your power potential with the stock manifolds and cats.

As they say, the bitterness of poor quality remains long after the sweetness of low price is forgotten. Buy once, cry once.

 

[91RS]

No these motors like shorty headers or just use the OE manifolds and put the money into Blackbear tune.

That is not true at all. Shorty headers are a total waste of money. The main restriction in a stock exhaust is not the manifolds.

 

[avalonandl]

Everybody has their opinions. I should have been more clear. LT headers are a waste of money on a 5500 lb SUV. The OE manifolds work well. On a 3400 lb Camaro LT are great....

The OE muffler does constrict especially if you SC the engine which I want to do.

 

[ls1frc]

LS1FRC, that is also one of the questions, to run a VVT cam or not, Don't have DOD so that is not an issue. Don't mind doing the longtubes, going to have the motor out anyway. Definitely not going to spend $1600 on exhaust or for that matter, probably not even $800. Maybe if I wrap the headers it might help keep the cabin quieter.

Still looking for a cam, I will tune from HP Tuners.

Thanks for your input.

Mike

I am doing my first VVT cam, have another thread in this section about my 6.2 swap. If you want, you can wait to see my results. I have HPTuners as well and have tuned for years, but all 3 bolt cam stuff never the VVT stuff. I don't want to make a recommendation before having firsthand experience with it.

From what I read, you'll gain an extra 20-30 ft/lbs of torque downlow with the heavy advance. I specced myself a custom cam, 215/215 115+7 then you retard the timing as the rpms approach redline.

When I added even a baby static 3 bolt cam (206/212) and deleted vvt in my 5.3, the lowend got sluggish, so for the 6.2 I made sure to keep VVT.

Also agree on not buying the ebay headers, at minimum go with the better chinese stuff that TSP sells.

 

[91RS]

Everybody has their opinions. I should have been more clear. LT headers are a waste of money on a 5500 lb SUV. The OE manifolds work well. On a 3400 lb Camaro LT are great....

The OE muffler does constrict especially if you SC the engine which I want to do.

It isn’t opinion. I’ve seen the dyno graphs. What evidence do you have?

 

[ls1frc]

Headers have always gained power everywhere. They are the best bolton you can do. The gains in a truck 6.2 are the same as the car. Of course the acceleration gains are half because the weight is doubled. Whether that's worth the $1600 is subjective.

This dyno below gains 53 ft/lbs.

 

[avalonandl]

None

It isn’t opinion. I’ve seen the dyno graphs. What evidence do you have?

None except common sense. Why put LT on a SUV? I don't want to race it....LT are great for tuning to a higher rpm power curve. Just ike I won't put a 4000 rpm stall converter in my Denali...If you want to drag race then that's great.

 

[FrankU]

Nice big gains everywhere ! Was that before or after the heads/cam install ?

Headers have always gained power everywhere. They are the best bolton you can do. The gains in a truck 6.2 are the same as the car. Of course the acceleration gains are half because the weight is doubled. Whether that's worth the $1600 is subjective.

This dyno below gains 53 ft/lbs.

 

[91RS]

None


None except common sense. Why put LT on a SUV? I don't want to race it....LT are great for tuning to a higher rpm power curve. Just ike I won't put a 4000 rpm stall converter in my Denali...If you want to drag race then that's great.

No, sir. That is not true at all. Now if you put 2” primaries on a N/A engine that will hurt low end a little but 1 3/4” headers absolutely do not hurt low end at all. Literally just watch the video in the post above yours. Does that look like it only made power on the top end? That sucker made power for the entire run and that’s on a stock truck! It actually gained more torque on the low end than the high end. Stall is dependent on the cam choice, not headers.

Mild VVT cam, long tubes, and a good tune will result in a very drivable and usable truck with power gains everywhere.

 

[ls1frc]

Nice big gains everywhere ! Was that before or after the heads/cam install ?

No idea, this was just a youtube video I found. But I have tuned and done headers on tons of 5.7-6.0 LS engines and they always pick up massive low end torque. It's the exhaust scavenging that does this, there is a science to longtubes. I wouldn't bother with shorties ever. Will not outflow factory manifolds + you get the annoying ticking sound from the thinner walls.

 

[ls1frc]

No, sir. That is not true at all. Now if you put 2” primaries on a N/A engine that will hurt low end a little but 1 3/4” headers absolutely do not hurt low end at all. Literally just watch the video in the post above yours. Does that look like it only made power on the top end? That sucker made power for the entire run and that’s on a stock truck! It actually gained more torque on the low end than the high end. Stall is dependent on the cam choice, not headers.

Mild VVT cam, long tubes, and a good tune will result in a very drivable and usable truck with power gains everywhere.

Correct

I will post the results in my 6.2 thread once this exhaust thing is done.

 

[73TA]

Well, that dyno sheet sure told a story that is hard to argue with. Not sure how much a tune helped over stock exhaust 6.2. Looks like I will definitely get a set of long tubes. Just need to find that "perfect" cam.

91RS, looking forward to your results.

I probably won't start my build for another month or so. Bought the Esky with the bad lifter, so I guess I do have a little money to do invest into without being really upside down on it. I paid $3200 for it, maybe that was to much, going to find out when I tear it down and see if there is any other damage. Haven't actually heard it run yet, need to pick it up (7 hours away from where I live) The woman who owned said that her mechanic said that it needs a new motor, because it has 200K miles on it.

Mike

 

[91RS]

My truck is already done but I didn't have any dyno graphs to post since I don't bother with dynos because the results aren't that accurate unless you can run on the same dyno before and after in the same weather conditions. I used a Comp Cams 156-401-13 that my tuner recommended with the phaser limiter, new phaser, HD LS2 timing chain and dampener, new lifters, PSI 1511 springs, BTR hardened pushrods, CHE trunnion upgrade, Melling 10355, ARP head bolts, and L96 injectors. I already had ARH catted 1 3/4" long tubes with a Corsa Touring on the truck. It feels fantastic, it actually turned out better than I expected. Keeping the VVT was the right choice because it has power everywhere.

 

[ls1frc]

Well, that dyno sheet sure told a story that is hard to argue with. Not sure how much a tune helped over stock exhaust 6.2. Looks like I will definitely get a set of long tubes. Just need to find that "perfect" cam.

91RS, looking forward to your results.

I probably won't start my build for another month or so. Bought the Esky with the bad lifter, so I guess I do have a little money to do invest into without being really upside down on it. I paid $3200 for it, maybe that was to much, going to find out when I tear it down and see if there is any other damage. Haven't actually heard it run yet, need to pick it up (7 hours away from where I live) The woman who owned said that her mechanic said that it needs a new motor, because it has 200K miles on it.

Mike

If you paid $3200 for the Escalade, that is an absolute bargain. I wish I could find a decent GMT900 with a blown motor, what a bargain.

 

[09_4WD_YUKON]

Check these out. Price isn't bad and they're coated too. These will be going on my Yukon before too long.

https://www.summitracing.com/parts/psm-72c2267