h3 engine swap thoughts!

[Expendable]

Here's a H3 with a 6.0, 4L80e and Atlas T-Case
http://www.pirate4x4.com/forum/vehicles-trailers-sale/1437593-h3-hummer-6-0l-4l80e-atlas-2-a.html

But I did some digging, it used to be supercharged and was pushed a bit:

[video]http://s33.photobucket.com/user/mx_racer_36/media/B58BABB6-6B4A-4AA5-8840-E8C7881730B1-15778-000013749B8B369F_zps85801638.mp4.html[/video]

 

[Kyle]

see with that much power id have way to much fun with it and go through tanks of gas in hours

 

[2010H3TAlpha]

Wow, that '09 is tempting to replace my Grand Cherokee with it. I bet that thing FLIES! Too bad that motor is probably a little tired after being blown.

 

[skeptic]

http://shop.predatorinc.com/raptorqperformancecomputer.aspx

claimed is not the same as actual. and it's most likely at the flywheel not at the wheels.

Also peak power is not what you want. you want a nice strong low end torque curve. that's where an engine swap would really count.

This. Even if 40HP is accurate, I want low end torque not just mid/high rpm HP. Plus, the V8 starts higher, you can chip the v8 or otherwise mod it for even more hp/torque if needed.

 

[chaos254]

has anyone provided feedback with a pcm tune? predator makes a pcm tune and it adds 40hp. lets say you had an 06 that comes with 220hp+the 40hp+airdocs with cold air intake 5-10hp= about 265hp if we play it low. thats not that far from the 300hp of an alpha. And say you had the 3.7 at 240hp now your a 285. thats even closer. i want someone with a pcm tune or predator tune to chime in and see if they say they can really "feel" the extra gain.

You can definitely feel the difference with the PCM tune. I dont know how much of that is an actual horsepower increase or just a better shift strategy. Im sure its both. Maybe I can find a 4 wheel dyno close by and see where im at compared to stock

Sent from my SCH-I545 using Tapatalk 2

 

[Kyle]

You can definitely feel the difference with the PCM tune. I dont know how much of that is an actual horsepower increase or just a better shift strategy. Im sure its both. Maybe I can find a 4 wheel dyno close by and see where im at compared to stock

Sent from my SCH-I545 using Tapatalk 2

When you say feel what do you feel? faster off the line acceleration? faster pick up times when passing? not having to push the pedal to the floor to get on the freeway? the other day for fun my friend and i wanted to compare his old toyota corolla acceleration to my h3 and that thing walked all over it and it only has 130hp probably at the crank, and account for the high milage its probably lost 20hp since 04.

 

[Expendable]

You can definitely feel the difference with the PCM tune. I dont know how much of that is an actual horsepower increase or just a better shift strategy. Im sure its both. Maybe I can find a 4 wheel dyno close by and see where im at compared to stock

Sent from my SCH-I545 using Tapatalk 2

If the PCM tuning for GM vehicles is anything like it is for Ford vehicles then there are tens if not hundreds of variables that can be used in tuning of the PCM. With my Crown Vic there are about 200 different settings that can possibly be adjusted from factory. Spark, timing, gearing, sensors can be deactivated, speed limits can be deactivated, and then if you have any other differences in the drivetrain (ie: bigger MAF, intake tube, exhaust, etc) those will be compensated for. Big difference will be timing of the shifts, sometimes line pressure for the shifts are adjusted.

Most vehicles with PCMs are tuned for longevity of the vehicle. especially those vehicles with electronically controlled throttle bodies, the factory can limit how fast the throttle body opens lessening shock to the drivetrain extending the life of the drivetrain without need for beefing it up. ex: the Hummer H1 Alpha is tuned so that take offs from standing still or slow rolls that there is throttle lag on purpose to lessen the shock on the transfer case.

 

[chaos254]

When you say feel what do you feel? faster off the line acceleration? faster pick up times when passing? not having to push the pedal to the floor to get on the freeway? the other day for fun my friend and i wanted to compare his old toyota corolla acceleration to my h3 and that thing walked all over it and it only has 130hp probably at the crank, and account for the high milage its probably lost 20hp since 04.

All of above. The overall driveability is so much better with the tune. With the tune my gas mileage is pretty much back to where it was before the 35s. Last fill up was 16.87mpg. Majority of that is city driving(work is only 10miles each way). When I switched to 35s, I loved the look but regretted it because the noticeable loss of power.

Sent from my SCH-I545 using Tapatalk 2

 

[Kyle]

All of above. The overall driveability is so much better with the tune. With the tune my gas mileage is pretty much back to where it was before the 35s. Last fill up was 16.87mpg. Majority of that is city driving(work is only 10miles each way). When I switched to 35s, I loved the look but regretted it because the noticeable loss of power.

Sent from my SCH-I545 using Tapatalk 2

okay, and you did a pcmforless tune right or the predator one?

 

[chaos254]

okay, and you did a pcmforless tune right or the predator one?

PCM of NC

Sent from my SCH-I545 using Tapatalk 2

 

[5gn-h3t]

I'll add my .02.

This has been visited many times in the past. I was going to do it myself. The easiest way to have the ultimate H3 is to buy an Alpha, swap in 4.56's, upgrade the 4L60E, and swap out the 5.3 for a 6.2. The 6.2 needs some mods to work but everything is relatively easy and off the shelf.

Swapping an I5 to a V8:
The Base and Alpha frames are different. The engine mounts are different. Early trucks have less firewall clearance. Later trucks ('08+, I think) use the same PCM regardless of engine. I 'think' you could do a segment swap in the late I5 PCM and use it to run the V8. Then you need to build a wiring harness, some fuel lines, move the AC compressor, etc. To make all of this work without any warning lights on is a lot of work.

I plan on doing a swap in the future. I know what it's going to involve. It won't be quick, cheap, or easy, but it could be the sweetest thing ever when I'm done.

To anyone planning on doing this to an I5 - go take your truck apart. Look at things. Compare them to pics of a 5.3. Look up GM parts diagrams. Read everything you can on GENIV V8 engine swaps. Look at component locations.

And good luck.

 

[SuperBuickGuy]

I'm going to try the PCM for less tune, and I was leaning towards a diesel swap.... but I'm really starting to lean towards a 6.2 swap from a pickup (with cylinder deactivation) to get better mpg. Honestly, I don't know which is more risky - diesel, which will be a PITA to smog; or 6.2, which won't throw codes so will pass easily, but could actually get me worse mpg.
my theory is based on experience. I've had a bunch of FJ40s (these are the best example, but certainly not the only), and the very first thing I'd do is swap out the 6 for a 350 chev. MPG was 11 -13 with the 6, to 15-18 with the 8... of course, there wasn't a point on the torque curve where the 350 wasn't better by a factor of 2.....
of course, that leads me to this. old FJs came with 5.38 gears, then in the 60s went to 4.56, then in the mid-70s went to 4.10 - I got my best mpg with 4.56s and 35s (all my FJs had 35s at some point of their career). I know it doesn't seem the same, but actually, the FJs weight almost exactly the same as an H3.

 

[Mr_Rich]

I seem to remember reading somewhere that GM didn't equip Hummers with cylinder deactivation simply because it would never activate the percentage of the time it would help due to the poor aerodynamics of Hummers. I think you want to balance your mods with your desire for economy on a swap.

 

[LagunaH1]

I just need some more time and money...

Famous last words...?

 

[Kyle]

maybe just modding the i-5 would be an easier and more achievable goal than swapping an engine, im getting a tune for my hummer that should add as much as predators raptorq tune, i already have exhaust, and intake done too, theres not much more i can do to gain more power other than a turbo or supercharger.

 

[Zach]

Why do you actually need more power?? You realize this is not a race car or sports car, right? This is an off road vehicle. These mods will not help you on the trail. It will only make it go boom! Just sayin

 

[06 H3]

Lol famous last words....we all need more time and money.

I agree with Zach, I only need more power not for the trail but for on road. I can barely hold 65 going up hill on the freeway. It's not that I need more power I really just need to regear but we can't do that without ditching the front axle so I need to some more power just for freeway driving which I do daily for work and school.

Even then Im not looking to have this thing be a race car. I just want to keep up with traffic and pass when I need to.

Your H3 is much lighter then 95% of the H3s on here. Just wait till you add skids, sliders and a winch. It's just gonna get slower. Same thing with jeeps...only way you can get ultimate power is highly modified offroad vehicles or go with an alpha or a raptor and even then you will want more. Mostly everyone on this forum always wants more...that's why they are never ending projects.

 

[Chook]

For those just looking for Highway/Economy improvements you could do a lot just by doing a 2wd mod (& make it selectable 4wd when you want to offroad/snow/ice etc.)

 

[skeptic]

Why do you actually need more power?? You realize this is not a race car or sports car, right? This is an off road vehicle. These mods will not help you on the trail. It will only make it go boom! Just sayin

I can't speak for everyone, but in my case I have an I5 in an H3T on 35s and I live in UT where I'm always going up or down hills, unless I'm going up or down mountain roads. Off road I'm usually just fine, although I have done a couple long really steep hill climbs where I was in 4-low with the pedal to the floor and really wanted more power. As much as my wife wants to buy a couple 4-wheelers or a side by side, until I get an Alpha or some other V8 powered truck my stance is we don't have anything to tow a heavy trailer with.

 

[Kyle]

yea the power isnt for the trail, its for on road help, passing and just keeping up with the flow of traffic on the freeway is tough with the 5 banger, in the city its not as bad, but i still would like to have more power.

 

[Zach]

****ers keep complaining try driving a 92 H1 with a three speed trans 6.5 back from Moab up the hills. Talk about a dog. Semis were passing me and yet you complain?

 

[LagunaH1]

92 H1 with a three speed trans 6.5

6.2

 

[06 H3]

Yea...I could complain I drove behind you! Lol

I won't complain though...I had logged some great mpg on the way out to Moab.

 

[Zach]

6.2

My mistake less power

 

[Zach]

Yea...I could complain I drove behind you! Lol

I won't complain though...I had logged some great mpg on the way out to Moab.

You weren't behind us when it died no power nada 33 miles outside of Baker. AAA thank you