Making the H3 more efficient!

[n8rfastback]

Well, I'm on a quest to make the H3 as efficient as I can. I only utilize it to haul my family, and dog, and as a daily driver to work and back when the weather doesnt allow me to ride my bike.

I get around 14 city, and 19 hwy right now. I just did an oil change (mobil 1), and made sure it has fresh plugs in it. It has a drop in K&N filter.

This week I replaced the stock vortec box with a PVC 3" pipe, definitely a noticeable difference. We'll see if the MPG goes up. I also just put in the super sparkz coil spring replacements. It does seem to idle a little smoother since doing that, time will tell if it helps efficiency at all.

I'm not going too far above and beyond, just simple bolt ons to get a little better mileage out of her, why not?

I am thinking next will be an electric fan kit, possibly a tune from PCMforless, and eventually a header and exhaust upgrade.

Oh and if you couldnt already tell, I'm a cheap SOB.

Whats the most effective way to get tuned? I've only ever had fords and just went with SCT tuners and can tunes... but I know GM's dont work that way.

Anyone have an HP tuners file they would like to share? lol I may have a friend or two with HPtuners that would be willing to help me set it up and tune the H3.

Anyway I'll be updating here as I progress and see what works best for easy and inexpensive gains.

-Nate

 

[davidh3]

Less weight = more mpg.
If you don't take your H3 off road, you can take off some accessories like brush guard, roof racks etc. Use manufacturer approved tires, either 32 or 33 inches.

Weird enough, I took the spare wheel off when I had my H3, that reduced a lot of weight.

 

[ABNTROOP]

Or you could sell the H3 and buy a damn Prius if your frugal and concerned with gas mileage! :giggle::roll:

 

[Kyle]

i took the spare tire off mine just for a day to see what the car was like with it gone and i could tell a major difference in acceleration and breaking etc! try pulling the spare off!

 

[Bigunit]

Get a KIA!

Sent from my DROID RAZR using Tapataint

 

[Ed's06h3]

Get a KIA!

Sent from my DROID RAZR using Tapataint

:funny

 

[ABNTROOP]

STFU! LMAO! :giggle:

 

[n8rfastback]

I never thought about the spare... But I kind of like having it on. Maybe I'll pull it this summer and see what difference it makes.

I'm frugal, but not to a laughable amount, and kias and prius's are for chicks....

Please don't get on here and suggest I get rid of the hummer cause the mileage will always suck, I realize that, and it really ain't bad at all for what you get to drive. I'm just trying to maximize what I can for my daily driver and mall crawler without getting ridiculous. I wanna see if I can reach 20 in town and 25 hwy with bolt ons and sensible driving...

Sent from Nates phone...

 

[n8rfastback]

I plan to stick with stock sized tires, and I have no external accessories, so that helps. I have considered getting a set of hwy all season tires too when the time comes, instead of a really meaty looking off road tire...

Sent from Nates phone...

 

[ABNTROOP]

:thumbs: Good luck with that whole thing

 

[davidh3]

I plan to stick with stock sized tires, and I have no external accessories, so that helps. I have considered getting a set of hwy all season tires too when the time comes, instead of a really meaty looking off road tire...

Sent from Nates phone...

:hmm:Ok, I can only think of reducing the weight and keeping everything bone stock...

Sorry, I can't come up with more ideas.

Ron46 might have some ideas, you can ask him.

 

[Kyle]

hey now, we have a 2012 kia optima hybrid and its a great car, theres no reason to bag on kia!

 

[Sethmark]

You need to increase the power and decrease weight and rolling resistance.

Find a lighter wheel and tire combo. If you're running an 18 go down to a 16. Smaller tire with a narrower footprint will help.

Pull out the carpet, back seats, ac compressor and exterior cosmetic accessories. I bet I could pull 500# out of it easy.

Find a tuner and advance the timing as far as you can without getting any knock. I'm sure there's a header available, get that and free flow the entire exhaust. Electric fan....proper cold air intake below the front bumper.

 

[n8rfastback]

I was thinking about lighter wheels and tires... I know most people want to lift and put 35's on the h3, well actually so do I, but it's just not how I intend to use it. I need to get real about it cause I know mine will most likely never go wheeling... Sadly.

Sent from Nates phone...

 

[SolidusJ]

I think I've done just about everything I could have for more power and MPG. Only thing left is SuperSparkz ported throttle body and that would pretty much be it and also a high flow hearder. I'm ditching the Jet's High Flow Mass Air Flow Sensor and adding K&N Apollo with the K&N intake and I'm sitting at 15 MPG street and almost 22 on the highway with 285 tires (about 90lbs each) and a 40" light-bar on the roof. If you want I would say get a Bullydog Watchdog System to plug into your OBD2 to get real-time MPG, air flow, temp and anything else you want to keep an eye on. One more thing I may have gone over borad but I warped about 100' by 2" of heat warp on the heard to keep the temp in the engine bay lower, not fun with the header still on I can tell you that.

-PCM E-fan Kit
-PCM Tune
-K&N Intake System
-K&N Apollo (When I get back home)
-Jet High Flow Mass Air Flow Sensor
-Flowmaster 40 Series
-Ac Delco Iridium Spark Plugs
-SuperSparkz Ignition Coil Spark Plug Spring Delete

 

[n8rfastback]

Man those tires gotta be killing it for you.

Sent from Nates phone...

 

[4speedfunk]

I'm cutting the top off my next H3. I got it all figured out...works like this:

1. Chop the roof and all five rear windows.
2. Remove the interior completely, aft of the front seats.
3. Remove rear window mechanisms and door handles...weld & fill.
4. Remove upper (glass) half of rear hatch door.
5. Relocate third brake light to spare tire.
6. Remove useless rear wiper system.
7. Remove rear sub-woofer.
8. Fab new sheetmetal interior bed walls, weld in place.
9. Fab new sheetmetal tops for the side-walls.
10. Rhino-line the entire interior.

The forward half of the cabin will remain hard-top and front doors will remain stock. I'm leaving the rear of the cab open to the bed....aka "Bronco" style, and I'm also keeping the sideways hinging tailgate. I'll be running custom aluminum bumpers and a canvas top. SAS and SOA of course...35" tires & 4.88 gearing. Possibly a stick? Possibly an Alpha? Definitely an Adv. Pak. So far I've only ever seen (2) Adv. Pak H3's without sunroofs...something I require to make this work. I'm not sure but I would love to crack 4200 lbs. with this 2-door, short-wheelbase pick-up.

 

[alrock]

Do you think you'll need to add a roll cage to stiffen it up a bit after removing all of that sheet metal?

 

[4speedfunk]

Great question. I don't know. A cage would be a good idea, not only for stiffness and protection, but...it also makes a great structure to stretch a bikini top over. I'm sure it would add back some additional weight, and it would also take some of the "trucky-ness" away from it. The biggest challenge will be (gulp)...the first cut. After that I think I can roll with whatever issues I find and solve them one at a time. Even though I'm cutting away 30% of the vehicle...its mostly superficial. It is a full-frame truck, and I'm hoping its rigid enough for this chop. I get the feeling that the original H3T concept vehicle came from this same basic idea. If you study the numerous GM photos...you can see its all a single body (not a separate cab/bed), and it even has small side-doors on the bed....clues as to where it came from.

I anticipate stiffness issues with the front half of the cab. After all I will have cut away everything behind the front doors! Even if I plan to keep the cabin open to the bed...it will surely need some sort of additional framing around the perimeter or partial knee-wall to help keep its shape. The H3 is made from very thin metal, and I might even consider grafting the rear cab wall of a Tacoma or Colorado onto it...sliding window and all. This is my plan "B" just in case I start having weather intrusion issues with the open cab. Jeeps seem to get away with it....not sure how well a topless Hummer will hold up to the occasional seat soaking.

This will be a TRUCK and I do intend to use this vehicle as such...firewood, mulch, dirt, junkyard parts, etc. It will not be a polished SEMA style poser-rig, or a half-baked concept. Also it will not be a backyard creation like some of the $900 XJs I've seen cut in half. I want it to look just like it would if GM would've made it...along with a few THORtweeks.

 

[ABNTROOP]

Well that's quite the task you've set for yourself, I look forward to seeing its fruition.

 

[4speedfunk]

Not sure it will be any more "efficient"...but, I like the idea of a light-weight 2-door T.

 

[MaxPF]

Getting rid of the full-time 4WD would likely make a big difference. Sadly, there is no easy way of doing it on a Hummer...

 

[4speedfunk]

I agree. I have considered buying a salvage H3 that has drivetrain issues, and just gutting the stock t-case. If this ends up being the case (no pun)...I would swap in a standard 2H/4H/4L driver-side drop (NP205?) and then instead of using a GM SA for the front, I'de grab a JK or Ford axle and move the entrie front driveline to the drivers-side. This would no doubt get into some electronic work, and I'm sure I would have to loose my TCS and Stabilitrac as well. I think this is the configuration that the BullyDog H3 has.

Right now to get 2wd I have to manually pull the front driveshaft. I've not driven around enough to compare any mileage results with the front axle shut-off. I sort of figured its mute point, considering the other mods on my truck. I guess I'm just not that concerned. I'm actually more interested in reducing front-drive wear & tear...and any sort of mileage gain would just be a side-benefit. However, on a stock H3, I think 2wd might show better MPG results.

 

[RamRod]

I have always wanted the ability to put it in 2wd!!!

 

[MaxPF]

205's are brute strong, but a part time chain drive case like a 241 or 261 will be more efficient. Pulling the front driveshaft on an H3 doesn't gain much - you'd still be turning the half shafts, and thus the carrier assembly, as well as the internals of the transfer case. You gotta get rid of all that drag to see an improvement.