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Long Tube Header Questions?

Big2dabank

Well-Known Member
Messages
1,216
Location
Central Florida
I have a pretty anoying vibration that appears to be coming from inside one of the Catalytic converters. I'm not sure if that is even possible, but it is a pretty anoying exhaust rattle. Its definately not muffler related, but I'm still chasing the rattle down and it sure sounds like its inside the cat to me. If it turns out to be a problem with one or both cats or even the exhaust manfolds, I am thinking of replacing both the echaust manifold and cats at the same time and was looking at a set of long tube headers from Stainless Works. They are rather pricey with the high flow cats, but it appears to be a good solution to replacing the headers and cats at the same time. Any opinions would be helpful. Here is the link to the kit i am looking at.

http://speed-eng.com/store/stianless-works-hummer-headers-offroad-p-8647.html.
 

twinmill28

Spilled Milk
Messages
1,545
Location
El Centro, Mehico (Way So Cal)
I don't understand why they are 03-06 and don't cover the 07 model? There should be no difference.
I've thought about putting long tubes on the deuce for awhile as everything I've read says shorties don't really make a difference. The thing I'm not fond of is the leaks that seem to be inherent with headers. I spent alot of years trying to make my last set of header bolts stop backing off and ultimately leaking.
I like the idea of headers because it will make the truck sound like a truck should sound. I did wheel with some of the Canadians who tend to have the cats removed by a company in Calgary that actually does a tune to make it work and the 08 that was just done was really loud. He was going to regroup and have different mufflers put on.
I'm curious to see how this works out for you. As for me, I'm past my teenage years where I thought headers would make power. They didn't, no on their own. But they do help the thing sound cool!
 

tomp

Well-Known Member
Messages
256
Location
Dallas
There is a difference in exhaust, starting in 07. Long Tube headers are a great improvement over stock and shorties! If you are going to spend that much money, spend a little more and get the best. Dynatech have the best quality, warranty and customer service out of all of them. Mine have been problem-free and that is much more that I can say for any other brand. Every other brand I have ever owned, were plagued with gasket leaks and welds that broke. Dynatechs use an OEM type metal gasket that do not leak and have a tight seal. Also their flanges are precise and very thick. Their entire kit is first class! They are well worth the cost and do offer noticable improvement in power throughout entire RPM range and throttle position. This was the best performance mod that I did to my H2. All other perf mods were a waste of time and money.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
Adding them, is a good time to replace spark plugs at the same time:)

Don't forget to use Anti-seize on all bolts and spark plug threads that go into aluminum heads
 

Tractordoll

Well-Known Member
Messages
130
Location
Western massachusetts
Looks like a nice exhaust. Is there any HP or performance increase? Good luck on solving your problem!

I don't have the same exhaust, I have a Borla setup and I have done a side by side comparison, the '05 H2 with headers, cats and exhaust vs the '06 H2 with stock. The 05 also has a cold air intake and a predator motorsports raptorq module so it's not exactly apples to apples. However, the difference is extremely noticeable and I don't mean just sound. The '05 has a lot more acceleration and just general power.It launches much faster and it seems to move along a lot easier especially with the 37" tires and the roof rack on it. The sound though is what differentiates it. If you never heard the '05 and only ever heard a stock H2 setup you would think it sounds okay and it actually does sound pretty nice. But the '05 sounds just awesome like a big truck should. That's been my experience. It was a pretty expensive mod, it added a lot more horsepower and a few years later required another pretty expensive mod when the transmission couldn't keep up with the horsepower anymore. Still it was worth it when compared side by side.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
Hi 3H and H.I:)

......I'm still around lurking - just been focusing on things here at home. I hope you guys are doing well
 

tomp

Well-Known Member
Messages
256
Location
Dallas
I did have a really cool idea for us some custom disconnecting sway bar end links that would limit travel and not fully disconnect. However, I dont think I could explain it well enough to help understand understand their value in aiding in offroad traction, etc. There just didnt seem like enough interest... Tha, plus the fact the Hummer line is no longer in production, it just didn't seem feasbile for me to invest the time/money in their development. There is a huge cost in design and development when I put a lot of thought into something because I want to do things better than we are used to seeing from the rest of the aftermarket offerings. I will stick around and keep reading, but time is limited with so many things going on. Take care...
 

Big2dabank

Well-Known Member
Messages
1,216
Location
Central Florida
Thanks for the feedback, I looked at the Dynatech long tubes also. I'll take your word for it Tom. I know youve been through quite a few more tweaks than me so ill go the Dynatech route. I trust your opinion quite a bit. Good to see you posting again.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
You will very happy with the quality and performance...

Factory plug wires work great with these headers, but not sure where you are with needing to replace the ones you have. I tried the aftermarket plug wires and the OEM wires just are made better.

It will take two guys and about 4 hours to install the kit, including new spark plugs. Just remember to be very careful snugging up the header bolts, as they go into aluminum...
 

tomp

Well-Known Member
Messages
256
Location
Dallas
Twinmill - I have the Corsa Touring exhaust kit. I dont think they make it anymore, as last time I spoke to them they only offered the Sport version of the muffler. Honestly, if I had to do it all over again, I would have kept the factory cat back system. There is just not enough performance gains to be had on a the H2 when replacing the cat back muffler. I tried several kits and I lost low end torque with each of them, thus the reason I went the Corsa route. The Corsa was the best out of the kits I tried. I re-gained the low end torque with the Corsa and gained even more with the Dynatech longtubes.
 

twinmill28

Spilled Milk
Messages
1,545
Location
El Centro, Mehico (Way So Cal)
Hey thanks tomp---I heard your truck a couple years ago in MOAB and it sounded great. Sound is what I'm after--I really like the factory rumble but would like it to be louder.
Did you do the Dynatech headers only, or did you get the kit with the cats? How does it all tie in together, do you have to cut up the exhaust system to make it work or was it built to fit like the factory set-up? Any drone in the cabin? I butchered the exhaust on my 3 and it droned to rattle your teeth out, my wife still doesn't forgive me for that. I need something that sounds good outside, but tolerable inside.
I'd like to do the headers alone based on your input of best mod for power--I want to see how it helps trailer towing.
 
Last edited:

MaxPF

AGNTSA
Messages
1,394
Location
The dark side of the globe
I tend to dislike headers on anything other than race vehicles due to the aforementioned issues and the often overlooked issue of greater engine compartment heat. Stainless helps, since it is only 1/3rd as heat conductive as steel, but wrapping with Thermo-Tec or an equivalent product is the best solution. It may not look as nice as the bare tubes, but it massively reduces the radiant and convective heat given off by the headers.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
Twinmill, the headers would work great with factory exhaust and their kit bolts right up to the OEM specific cat-back systems. This system does not have any of the inherent header problems like all others do. These are first class headers and even better quality and longevity over the OEM exhaust manifolds. I have the high flow cats and would not suggest them without the complete kit. I have had ceramic coated headers before and would not do that again, as it peels/flakes off over time. The Dynatechs are thick walled stainless and expel the heat better than OEM manifolds. This kit does increase low end torque and throttle response which is far better than all the losses that will results in these areas with all other exhaust changes compared to the OEM setup. With this kit, you get what you pay for! I dont endorse any product unless I have used it and can report back with good results - I am not easy to please either;)
 

Big2dabank

Well-Known Member
Messages
1,216
Location
Central Florida
I found a local speed shop that specializes in GM LS series motors. They are a vendor for Dynatech and highly recomend their products. They are putting a quote together for me to order the headers and perform the install. I have the option to install myself if I choose. I'll let you guys know how it turns out.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
I had mine installed as well, but I assisted so I could do the plugs, ensure anti-seize was used, etc. Even though I could have done it myself, it's one of those pain in the butt jobs that I didnt want to deal with...LOL.
 

twinmill28

Spilled Milk
Messages
1,545
Location
El Centro, Mehico (Way So Cal)
Putting the headers on myself is not an issue for me--though I have to constantly remind myself that I'm not the 140 pound teenager I used to be who could flex in and around the engine compartment and slink under the truck nearly like I used to. I think I ate that 140 pound kid!
I like doing header/exhaust work as I've always got to run it without exhaust around the block at least once just to make lots of noise. Open headers are the bomb! And don't give me that "sucking a valve" crap either--I've never seen it or done it!
 

Big2dabank

Well-Known Member
Messages
1,216
Location
Central Florida
Found the problem last night. It was definately the passenger side Cat. The substrate inside the Cat had come loose and was rattling like crazy.

photo 2.JPG

Tomp,

Do the Dynatech Long Tubes increase the exhaust drone in the cab of the truck. How much louder does it get at the exhaust tip. I noticed when I cut out the cat and replaced with just a stright piece of pipe, my exhaust is about twice as loud at the tip. Not very user friendly to drive around.
 

tomp

Well-Known Member
Messages
256
Location
Dallas
It is a different sound, due to the thinner stainless, compared to the thick OEM manifolds. However, the kit is not louder and is a very pleasant performance sound. The final output sound is a nicer performance sound - I really like it. I don't like drone or sound louder than stock and this is why I run the Corsa touring cat-back setup. The overall sound is very nice!!! You will be very pleased with it...
 

Big2dabank

Well-Known Member
Messages
1,216
Location
Central Florida
It is a different sound, due to the thinner stainless, compared to the thick OEM manifolds. However, the kit is not louder and is a very pleasant performance sound. The final output sound is a nicer performance sound - I really like it. I don't like drone or sound louder than stock and this is why I run the Corsa touring cat-back setup. The overall sound is very nice!!! You will be very pleased with it...

Thanks Tom, I placed my order today. Here is what everything is costing for those of you interested in doing this. I decided to go with their performance tune, since it was so cheap after the discount.

$799.99 Dynatech H2 Headers
$599.99 Dynatech H2 Y-pipe with High Flow Cats
$44.95 STG-8900 LSx Stage 8 Locking Header Bolts
$23.92 8 NGK-TR55Spark Plug
$31.16 Exhaust Manifold Gaskets
$495.00 DynoTune Full with A/F readings.
$500.00 Labor and Installation
$-200.00 Good customer discount

Total roughly about $2,295 installed and tuned. Not a cheap mod at all, but I'm sure I'll be pleased with the results, especially since both my cats are failing so I would of needed to spend about $500 of this total regardless.
 
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