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Hummer H2For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.
I went down that rabbit hole with my 05 and ended up just building a new engine for it instead.
Your best bet with the weight is a PD blower. Whipple has a kit for the cathedral port heads on your truck but they are hard to find.
Having sold my H2 and since purchased a Yukon with a 6.2 and 10 speed, if I had it to do all over again I would get a junkyard pull out with harness and go that route. The 6.2 has more than enough power. There might be other alternatives too but I can not say enough about this combo. My truck weight less but even with a mild canned tune I can leave most Mustang GT's wonder what the heck just happened when I leave them at a light.
Your 6.0 depending on mileage may or may not need some work (think cam bearings) it's a whole lot of work to tune with just about any power adder and if you get past that then the 4l60e transmission is bound to grenade on you. You'll need to address the intake, throttle body, fuel system, injectors and cooling systems for anything accept a Whipple with its stock tune.
Just my opinion but I wish you the best of luck.
TH
I have an 07 H2 with a Vortech Supercharger on it , I changed the gears to 4:88 and replaced the transmission with a stage 3 built to handle 650 HP, 6 " lift with 37's . Has more than enough power.
Payload has a huge effect on thrust! 2008 Hummer H2->0-60:7.10 sec 2003-07 Hummer H2->0-60:10.7 sec
It'll get up and go!!! Everyone said they were slow! If I do 55 mph on the highway, I can get 16 or 17 mpg. I'm not sure if it was tuned or what, but putting a diesel in it is seeming less of a necessity. I know it'd get better fuel mileage, but the pricetag...
A buddy of mine has an 6.0L H2 on 37s with a tuned MagnaCharger package, it is impressive, and eats Transmissions sprinkled with dirt as a snack.
Went through three in three years, the original OEM build in a couple months post SC. Then a HD re-build 6-8 months later, then had it rebuilt like crazy to "handle the power" and toasted that one about 12 months later.
Thanks for the advice. Will a supercharger damage my transmission? I am using my hummer for work and it's doing a great job for its designated function. I am not a mechanic so I would hate to do something to my truck that I couldn't fix.
I have played with both in my earlier years and as others have mentioned a supercharger will provide immediate boost and give you a great deal more power out of the hole which is where you want it, turbo's provide more free hp at high rpm's. My preference are superchargers over turbos.
The next question is much easier to answer , now will they damage my transmission? Yes. The max torque rating of the 4l60e/5 trans used in the H2 is 360ft lbs which just happens to be the max torque that a stock LQ4 engines puts out.
Unless you plan on sending off the trans to an aftermarket performance rebuilder or replacing it with a 4l80 your stock tranny will be on borrowed time (especially if its got some high mileage on it now). The average H2 trans lasts about 130k mile with good care bolting on power
mods, not following service intervals or just romping on the throttle will quickly reduce that number.
Considering the weight of the H2 GM should have put the 4l80 as they did in the 2500 and 3500 trucks weighing about the same. The 08 and 09 got the 6l80 which is rated about 100lbs better then the 4l60e/5 but still not as good as the 4l80 and the choice of those hot rodding or building a superduty H2.
I have played with both in my earlier years and as others have mentioned a supercharger will provide immediate boost and give you a great deal more power out of the hole which is where you want it, turbo's provide more free hp at high rpm's. My preference are superchargers over turbos.
The next question is much easier to answer , now will they damage my transmission? Yes. The max torque rating of the 4l60e/5 trans used in the H2 is 360ft lbs which just happens to be the max torque that a stock LQ4 engines puts out.
Unless you plan on sending off the trans to an aftermarket performance rebuilder or replacing it with a 4l80 your stock tranny will be on borrowed time (especially if its got some high mileage on it now). The average H2 trans lasts about 130k mile with good care bolting on power
mods, not following service intervals or just romping on the throttle will quickly reduce that number.
Considering the weight of the H2 GM should have put the 4l80 as they did in the 2500 and 3500 trucks weighing about the same. The 08 and 09 got the 6l80 which is rated about 100lbs better then the 4l60e/5 but still not as good as the 4l80 and the choice of those hot rodding or building a superduty H2.
I’ve got the 08 with the 6l80. The family has had two of them. Both the transmission went out really early. The first one at less than 30k miles, the first one on the second h2 went out at 70k. Though the replacements have held up pretty well. I’ve heard gm has made many improvements since the first generation that the h2 got from the factory.
Right now I’ve got a magnacharger kit that makes about 6psi of boost. It improves the drivability a lot and really gets up and goes. The new trans seems to be holding up ok for the past 20k miles. The only thing that concerns me is how hot they can get during the summer. Over 200 degrees with normal driving is pretty unacceptable though gm says that’s ok. I’d like to invest in a cooler at some point.
I think on these trucks a supercharger is the way to go since the power is instant and the power curve is flat and consistent throughout the rev range. It feels like it has a bigger motor and there’s no lag anything to deal with. It’s just easy.
I’ve got the 08 with the 6l80. The family has had two of them. Both the transmission went out really early. The first one at less than 30k miles, the first one on the second h2 went out at 70k. Though the replacements have held up pretty well. I’ve heard gm has made many improvements since the first generation that the h2 got from the factory.
Right now I’ve got a magnacharger kit that makes about 6psi of boost. It improves the drivability a lot and really gets up and goes. The new trans seems to be holding up ok for the past 20k miles. The only thing that concerns me is how hot they can get during the summer. Over 200 degrees with normal driving is pretty unacceptable though gm says that’s ok. I’d like to invest in a cooler at some point.
I think on these trucks a supercharger is the way to go since the power is instant and the power curve is flat and consistent throughout the rev range. It feels like it has a bigger motor and there’s no lag anything to deal with. It’s just easy.
The 6L80 was a major improvement for the H2. The biggest problems with the early 6l80's were 1-2-3-4 piston cracking as well as drums failing. GM corrected these problems early. Any rebuilt trans you get from GM will have these upgrades already included and any rebuilder worth half their salt replaces these parts on rebuilds.
As you mentioned heat is a real killer on transmission and you must keep that at bay.
12-26-2022, 11:17 AM
