Rear mount turbo
 

I was thinking about doing a rear mounted turbo set up on my H2 for a little more oomph and some better fuel mileage. Just wondering if any on here has ever turbo'd a 6.0 H2.

Re: Rear mount turbo
 

I've been reading a bit about these and the first thing that pops out at me as a 'problem' is the air filter that mounts on the unit.

Unless your truck's going to be a pavement pounder I don't think it's wise to have any kind of air intake that close to the ground. You get in some deep water or do some splashy-splashy and you're screwed...and not the good kinda screwed.

Re: Rear mount turbo
 

I understand where you are coming from and completely agree. You dont have to mount the filter on top of the turbo inlet ... You can remotely mount where the turbo gets it air. I dont plan on burrying my truck in water or mud but here washington trails with down tree's, rocks, and snow would be of interest to me.

Re: Rear mount turbo
 

A turbo will guarantee you will need a tranny rebuild (w/ limited lift again) or a 4L80 conversion. The stock tranny will not hold up to any measurable power adder. For what your going to spend, you will not get a sizable MPG increase to justify it.

Put some gears in your rig if you want some better throttle responce.

Re: Rear mount turbo
 

My tuner and I have been doing some investigating and have found that we may be able to see as much as a 100hp gain to the wheels in as little as 6psi. I fail to see where my tranny would implode from a hp gain of 100 at the wheels when these trucks were designed to tow.... I have no intention of using my rig for towing and or hot rodding. Just a little more power so the engine doesnt has to work as hard going uphill, against headwinds and from dead stops. 11mpg is pure crap and I blame GM for a undertuned engine. We are hoping for 16mpg,s with 6psi. The boost via turbo will help immensely with underpowered highway driving conditions, fuel atomization and is a better option than a blower because there is no parasitic horse power loss. I am new to hummers or should I say GM SUV's but not at all new to forced induction. Being that I have not seen hardly any H2's out there with turbo kits I am willing to take a stab at it and notate any considerable gains (whatever they may be). I wouldnt mount the turbo just simply for "gas mileage" either, but I am a person that likes challenges. I bought the H2 because of the sheer size, presence, and comfort. Now I want to make the engine a little leaner.

Re: Rear mount turbo
 

16! LOL! You better get a diesel and still go light on the right pedal.

Good luck, dude. A quick search on 'superchargers' on this forum will give you an idea of the tranny issues you'll likely run into with turboing the 364.

Don't blame GM for an 'under tuned engine'...blame them for making the damn truck a 3 ton square. I'm with MUD...get some gears.

Re: Rear mount turbo
 

I dont have a problem w/ the "3 ton square" ;)

I would just like a logical reason from who ever was the ******* that decided to put a passenger car tranny in the "3 ton square".

GM has always had a lot of unspoken rules....No car shall ever exceed the power/speed of the corvette. Someone got fired in pontiac in 89 for that...underrating the 3.8L turbo trans am. Smoked the vette...hell it smoked the vett up untill 92 or 93.

The H2 would of been unstoppable if they put the 4l80 series in it. I think it was intentionally done.

Its like throwing a turbo in a camaro, now double the weight of the car, and add a couple thousand pound trailer to it. How long do you think that tranny would last?

Re: Rear mount turbo
 

I do all of my own work on every single vehicle I own... If that tranny ****s out then so be it. Ill put an 80 in the pig. But positive displacement superchargers have a completely different power curve then a rear mount turbo. The turbo will have a more gradual hp increase where as a positive displacement blower is instant impact. It's the sudden jolt of HP that is most detrimental to trannys and everything else follows suit.

Did you guys know the "roots" style blowers that are so popular on the H2's are actually the same stock blower on 03-04 Cobras? The Eaton M112 is what comes on the Terminators from Ford and the Magnum Powers is basically a glorified M112. The Whipples and Kenne Bell's are the same line that the Cobra's run as well. I know ALL of these blowers well and I know how hard they are on a drivetrain. They hit like a 9lb hammer and boost is almost instant. I know this cause I have a built 03 Cobra with a Whipple running 20lbs of boost making 650rwhp. That being said even the "bulletproof" T-56 gets worn out from PD blowers over time.

And I dont think a 33% increase in highway fuel mileage with a CAI, Rear Mount Turbo and custom tune is ridiculous.

Re: Rear mount turbo
 

MUD, can you post up some info/link about a 4l65 to 4l80 upgrade for an H2. I did a quick search on the forum and Google and came up with some, but not much.

You seem like you've got some knowledge...please share.

Re: Rear mount turbo
 

I believe mechanically they bolt up the same but you need to run a different computer for the 80 vs the 60. That would be my only assumption granted I am not GM literate but I have done my fare share of swaps in other vehicles. **** you may even be able to flash the computer for the 80 instead of swapping. assuming that the tranny's in H2's have independent controllers for the transmissions.

Re: Rear mount turbo
 

These guys have everything needed, even the cross member.

http://www.transmissioncenter.net/4l60e.htm#4L60E to 4L80E

You can use your origional computer w/ a custom tune to run the 4l80.

I dont remember any detailed posts on any of the hummer forums, but if you check out performancetrucks.net or ls1tech- They have tons of info there.

Re: Rear mount turbo
 

Thanks