6.2L & 6l80 Power Uprades

[ryaleon]

So I have done a fair amount of searching and there just isnt much info on the 08-09 H2 power train.

I am not after a drag truck by any means. I just want to add enough power so that I can spend a little more time in 6th gear and I want to avoid having to down shift so often going up hills.

What are my options? Gears? Supercharger? Any info is much appreciated.

[jsbihn]

ryaleon,
Not sure exactly what you are looking for since you are asking for power but also saying you dont want to down shift much.

To begin with these engine are in basic essence an iron block Corvette engine (LS1/LS2). So if you want some power, you can do all the simple mods that help Corvettes get power (intake, long tube headers, exhaust, cam....).

As for the tranny shifting, you can re-program it to help you out. But remember you have the 6 speed, which is what most want.... so you are already doing better with the shifts then most.

If you want better acceleration, then I would suggest dropping some gears in it, it could help you out also. Just remember to plan out your gears.
- I say that because if you plan to go with some larger diameter wheel/tires setup after you choose your gears you could end up going slower then you want. Like I am planning a mild 2-3 inch lift with some 37's at least then after that I will probably do at least 4.88s

Dont go running around dropping money trying to get what you want. The basics will get you what you want and all of this could be done fairly cheap. I can only see the gears costing you alot if you are unable to install them yourself and arent familiar with setting the backlash

[ryaleon]

I just don't want the Deuce to have to struggle so much going up hills at highway speeds. It always has to downshift to at least 4th and sometimes 3rd. Riding around town it has plenty of power. It's just the highway power that I feel is lacking.

I have 37x13.50s on it right now. So maybe the gearing is the answer.

[LoJac963]

pff try rockin the 4 speed like most of us have. Hell it will downshift from 2nd just going up a slight onramp.......

[ryaleon]

I had the 4 speed for a couple of years....definitely don't miss its highway power haha.

[ryaleon]

Does anyone make a true cold air intake for a deuce? Something that takes actual cool air in.

[jsbihn]

Originally Posted by ryaleon

Does anyone make a true cold air intake for a deuce? Something that takes actual cool air in.

I dont know why people this this is some sort of rocket science or that it has to be a "manufactured" product.

Plan out where you want the air to come from.
Its an off-road vehicle so some people will make a snorkel (yeah I heard some say the snorkel looses power, but if you do that are you doing it for power or for protection?), or you can route it to the front of the rig, or to the side of the engine bay where it collects it now.

All you need is some pipe (metal, stainless, PVC, whatever), some hose couplers, some screw type clamps, and a performance filter as big as you can shut into the area you want to put it in.
You get all that together for about 50 bucks (if that... since the biggest expense is the filter and you can get those fairly cheap from Amazon or eBay).
After that, you can take some plexi, or some metal, or again whatever and fab up a nice box to encase the HUGE air filter and done!
A little paint and it is all pretty
You now have a great CAI for a few hundred less then what you would have paid to buy one that isnt exactly what you want.

Why spend 150-350 bucks (or more) on something that - at best - gives 10-20 hp all because it looks pretty. Sorry but I dont drive around with my hood open all the time for people to see.
Fab up something for a few buck and take the extra money and invest it into another mod that you can fab up



Hope this helps

[ryaleon]

Now this has me thinking...it would be fun to build my own intake.

[H2Much]

Ryaleon, gears is your answer, especially if you are pushing 37's. that will give you the instant return to the stock feel once you get that ratio right. I suggest going 4.88's as that is as big as you can go on the front. Adding intake and exhaust and headers in that order will help too, but you need the gears first. Any time you go up in tire size you should be looking to regear so that your power gets rebalanced correctly. You don't do this, this is why you downshift so much. Your engine has almost 100 more horsepower stock so you have plenty of power. We have to do tons of mods just to get near where you are stock.

In short- regear is your answer.

[guruerror]

Originally Posted by H2Much

Ryaleon, gears is your answer, especially if you are pushing 37's. that will give you the instant return to the stock feel once you get that ratio right. I suggest going 4.88's as that is as big as you can go on the front. Adding intake and exhaust and headers in that order will help too, but you need the gears first. Any time you go up in tire size you should be looking to regear so that your power gets rebalanced correctly. You don't do this, this is why you downshift so much. Your engine has almost 100 more horsepower stock so you have plenty of power. We have to do tons of mods just to get near where you are stock.

In short- regear is your answer.

Agreed...'gears'...when I went to 37s the umph dropped. I moved to 4.56s and it ended up a tad snappier that stock. 4.88 will pump it up another notch, but be mindful of your top end...your RPMs will be higher on the top end the lower you go with your gearing. So if you do a lot of highway travel 4.56s might be more 'fuel efficient' for you than 4.88s.

This tool might be helpful in your decision making process: http://www.4lo.com/calc/geartire.php

If you're dead set on going the CAI route AND if you don't plan on serious off-roading, you could always replace the stock air box with a K&N and cut a section out of the hood directly above and mount a universal scoop to force outside air in. That would be better IMO than a snorkel...snorkels are worthless unless you plan on submerging your vehicle in water that can reach over the air box, and if you're in water that deep you better have a diesel or you'll have more worries than water in your intake.

These Landys, FJs, Jeeps, and whatnot that run around town with snorkels crack me up...99.5% of the snorkels I've seen were installed merely for show.

[LoJac963]

Right but the stock intake system draws air in from the fender which is cool air. Most systems just suck in hot air from the engine compartment.

I think the stock system is perfect which is why I went with a Volant box.

[ryaleon]

This is all great info. I will most likely regear. What do I need to know about this? Is it too much for a home mechanic to do? Where can I get parts?

[MVR 155]

Stock GM tuning leaves quite a bit on the table, I would love to tune my truck but I have a GMPP major guard for another 2.5 years that I don't want to be voided. Check out Nelson performance, highly recommended for GM trucks.

Another thing..... for the guys with the 2003-2007 trucks suggesting 4.88 gears..... The 08/09's stock have 3.73 gears vs. 4.10's that come in the 03-07's. That is a major jump in gearing for a tire that is only about 2 inches taller and will certainly have you turning some high RPM's on the highway. Going from a 3.73 to 4.88 will have you going from about 1700rpm on the highway to over 2200 (assuming approximately 75mph). The 6L80 also has a very steep first gear ratio of 4.027 which could make for some jerky driving at low speeds. Before jumping up that much I would see if you could talk to someone who has done this in a 08+ truck.

[guruerror]

Originally Posted by ryaleon

This is all great info. I will most likely regear. What do I need to know about this? Is it too much for a home mechanic to do? Where can I get parts?

I got mine at Trail Duty: https://www.trailduty.com/index.php?...c27c864fc4998f

You'll need the fronts, rears, and an install kit.

It's hard for me to comment on the install since I had the shop do mine, but I think if I had the 'time' on my hands and knew that I had the appropriate 'tools' that I could have done them; there doesn't seem to be anything obvious that jumps out at me as being super difficult. Surf YouTube for instructional vids on swapping gears in a H2/2500 4WD or similar...that should give you a better idea.

Originally Posted by MVR 155

Stock GM tuning leaves quite a bit on the table, I would love to tune my truck but I have a GMPP major guard for another 2.5 years that I don't want to be voided. Check out Nelson performance, highly recommended for GM trucks.

Another thing..... for the guys with the 2003-2007 trucks suggesting 4.88 gears..... The 08/09's stock have 3.73 gears vs. 4.10's that come in the 03-07's. That is a major jump in gearing for a tire that is only about 2 inches taller and will certainly have you turning some high RPM's on the highway. Going from a 3.73 to 4.88 will have you going from about 1700rpm on the highway to over 2200 (assuming approximately 75mph). The 6L80 also has a very steep first gear ratio of 4.027 which could make for some jerky driving at low speeds. Before jumping up that much I would see if you could talk to someone who has done this in a 08+ truck.

Which is why I recommended the gear calculator (http://www.4lo.com/calc/geartire.php) it'll let him compare various combinations to stay with a stock final ratio and keep the truck in it's powerband.

[ryaleon]

Seems I would be better off with 4.56 vs the 4.88. 4.88 seems like a huge jump from 3.73.

[ryaleon]

seems like it would close to $900 or so for parts if i were to order myself. I'm assuming about the same price for shop labor.

The gear calculator says that my effective ration right now is 3.53. says new gears 3.94, low gears 4.3, and high gears 3.59. Im looking at getting closest to the low gears right?

[guruerror]

Originally Posted by ryaleon

seems like it would close to $900 or so for parts if i were to order myself. I'm assuming about the same price for shop labor.

The gear calculator says that my effective ration right now is 3.53. says new gears 3.94, low gears 4.3, and high gears 3.59. Im looking at getting closest to the low gears right?

Lower gears will give you more take off and umph...but will increase the RPMs on your top end. Seems like 4.10s would put you closest to the stock power band, but that sucker will prolly jump off the line with 4.56s.

[ryaleon]

Then I think 4.56 is the way to go. I'm not concerned with mpg much....it's a Hummer after all the price of gas pays my salary so not an issue for me. I want it to be torquey! I'd like the deuce to be quicker than my dads 6.7 Diesel F250

[KT2T]

Originally Posted by MVR 155

Another thing..... for the guys with the 2003-2007 trucks suggesting 4.88 gears..... The 08/09's stock have 3.73 gears vs. 4.10's that come in the 03-07's.

I went looking for this information before MVR 155 posted the above and found this:

http://www.vibratesoftware.com/html_...MER/Hummer.htm

On that page, it lists 2003-2008 with 4.10 but that the 2008 optionally has 3.73. If this is the case, how would a second-hand owner of a 2008 validate what's already in the truck to determine what gearing to move to? I have also put 37x13.50 Interco SS M16 on my truck and have been thinking about re-gearing (thus my interest in this thread).

[guruerror]

Originally Posted by KT2T

I went looking for this information before MVR 155 posted the above and found this:

http://www.vibratesoftware.com/html_...MER/Hummer.htm

On that page, it lists 2003-2008 with 4.10 but that the 2008 optionally has 3.73. If this is the case, how would a second-hand owner of a 2008 validate what's already in the truck to determine what gearing to move to? I have also put 37x13.50 Interco SS M16 on my truck and have been thinking about re-gearing (thus my interest in this thread).

You need to look up the RPO codes...I think they're listed on the sticker in the glove box or door jam...can't remember.

It'll look like this:



There's a site (http://www.compnine.com/) that supposedly will decode your VIN and lookup your RPO codes automatically. Seems like it used to be free, but now they charge $5+, but I've never seen one of their reports, so I can't speak to how thorough it is. If you Google "compnine" though you'll find that a lot of people talk about using it...

You could also manually look up your RPO codes using this site, http://www.c2e.info/rpocodes/gmrpocodes0through4.html, one of them is bound to reference the gearing option on your rig.

Hope this helps.

EDIT: It looks like it'll be an "G" or "H" code...like "GS3 : AXLE REAR, 3.73 RATIO" or "H05 : AXLE REAR, 3.73 RATIO"