h2 feeling a bit sluggish when towing, what are my options to increase torque?

[kalantar]

I am coming upon 9 years of ownership of my H2 and with almost 90k miles on it, it has been rock solid. But lately after towing my toy hauler around it seems the H2 is getting a bit sluggish (only when towing). Any thoughts on what it could be? I haven't had the 100k service, which I plan on doing soon and there are no error codes.

I am also limited on where I can tow my toy hauler, steep grades are out of the question. This forces me not to travel as often as I like or to places I would like to go with H2. Ofcourse buying a diesel truck is an option but I really do not want to buy another vehicle. Any thoughts on increasing the torque/power? I was considering doing the diesel upgrade but I didn't want to drop that much coin and the reliability factor is huge for me.

Is the turbo option a good long term/reliable option? Any other options out there?

Any input would be appreciated.

[HummerMann]

I've looked at supercharging mine several times. Mark can tell you a lot of the costs and performance differences in supercharging vs diesel. I've also read on the brand X board that the Z06 LS7 505 hp engine is a straight forward bolt in on the H2 except for the electrical harness and need for a custom oil pan. The dealers are quoting 15k for the LS7 crate engine, but I've seen them on EBay for 12k. My next concern would be if the transmission could handle that extra hp and torque. For less than half that though you can put on a supercharger.

[[__--MUD--__]]

Multiply the existing power you have by putting in some decent gears. If you multiply the engine power better have room in your budget for a real transmission (4l80).

[kalantar]

I have 37's with 4:56 gears on it. The gearing has helped but at times I need that extra push to go up the steep grades. A new engine @ 12k plus is more than I would like to spend now, that is good gas truck money there. I was hoping something around a few thousand dollars.

It seems the turbos aren't a good long term solution as well, what about other engine mods? Headers, bigger pistons, anything?

[tomp]

Dynatech long tube headers & high flow cats, volant intake, diablo predator programmer! If towing regularly with 37s, you really need 4.88 gearing, imho

I'd also strongly consider electric fan conversion

[[__--MUD--__]]

I had 4.56 and I thought it was a turd....I'm at 5.13 now.

[kalantar]

Originally Posted by tomp

Dynatech long tube headers & high flow cats, volant intake, diablo predator programmer! If towing regularly with 37s, you really need 4.88 gearing, imho

I'd also strongly consider electric fan conversion

How much power increase will the header, cats , intake and programmer make? How much would it cost?
I tow 2x a year about 200 miles each way currently, the most I would tow would be 6 or 7 times a year if my h2 could pull it up the steep grades.

What is an electric fan conversion?

[kalantar]

Originally Posted by [__--MUD--__]

I had 4.56 and I thought it was a turd....I'm at 5.13 now.

I asked the shop several times if I should go with 4:88 and they insisted, it would be gutless. Will look into the gear upgrade.

[kalantar]

I found this off the net which answers most of my questions but how much of an improvement can I gt from the following?




Air Filter Upgrade

Upgrade to a free-flow aftermarket air filter (K&N or Fram Air Hog)
Go High-Tech

Install a power module to enhance the vehicle computer.
Add an ECU

An Electronic Control Unit (ECU) can change fuel and timing to make your engine more efficient and powerful.
Cool the Engine

Add a new aftermarket cold air intake. The complete cold air intake will make more horsepower because it draws cooler air away from the engine.
Improve the Exhaust

Install an aftermarket exhaust, remembering that you will want a larger diameter than your stock exhaust system. Also the less bends the exhaust system has the better.
Go with High Flow

A high flow catalytic converter can also add horsepower.
Forced Induction Systems

Look into forced induction ? adding a turbo charger or super charger. You will need to make modifications to the fuel system, with the extra pressure in the engine you will need more fuel and at a faster rate then before.

[tomp]

Don't do what the Internet tells you, use the EXACT brand items I suggested or all bets are off! The brands I suggested are proven on an H2! The electric fan conversion can be searched on this forum, but basically adds both HP and torque by eliminating the manual radiator fan.

[[__--MUD--__]]

Originally Posted by tomp

Don't do what the Internet tells you, use the EXACT brand items I suggested or all bets are off! The brands I suggested are proven on an H2! The electric fan conversion can be searched on this forum, but basically adds both HP and torque by eliminating the manual radiator fan.

I'm still up in the air about the electric fan conversion... Yea, your motors not physically spinning the propellor. I have not seen any actual numbers for the amp load on the dual electric fans. The alternator is whats going to be turning harder now while the fans are on...its not just free electricity. It takes the same x amount of energy to cool the motor down direct mechanically or electrically. We are not talking about gaining extra cooling capacity here, just freeing up extra power...Guess its going to come down to how often the fans are actually running. Every little bit helps, but were driving pigs 4x the weight of some of these jap cars. That why I have a hard time seeing some of these mods are justifiable.

I'd really love to see some dyno numbers on alot of this ****.

[[__--MUD--__]]

Originally Posted by kalantar

I asked the shop several times if I should go with 4:88 and they insisted, it would be gutless. Will look into the gear upgrade.

Someone had their gear knowledge reversed. The higher ratio you go, the more torque you get. There are a few sponsors off performancetrucks.net that have hard to beat pricing on good quality gears.

this is an excellent calc. I've posted all the values needed a number of times if you do a search. Compare multiple valuse side by side, rpm @ speed, etc.

http://www.grimmjeeper.com/gears.html

For starters just look at how small the difference is between stock and 4.56.

[twinmill28]

Originally Posted by [__--MUD--__]

The alternator is whats going to be turning harder now while the fans are on...its not just free electricity. It takes the same x amount of energy to cool the motor down direct mechanically or electrically. We are not talking about gaining extra cooling capacity here, just freeing up extra power...Guess its going to come down to how often the fans are actually running.
I'd really love to see some dyno numbers on alot of this ****.

What? The alternator is turning harder?
The alternator load on the engine will be the same regardless of adding accessories that draw more power, just in bigger power draw cases like stereo amplifiers or winches it may not be able to provide all the power that is needed. An alternator does not have a clutch on it like an a/c compressor, which can load up the engine a little more when it engages. So, no, not extra cooling capacity--but slightly less load on the engine=more power, possibly cooler engine. Gain may be negligible, but it will be a gain no less.
Removing the fan/clutch will free up some load on the engine for less drag, plain and simple. I'm not sure of the gains of doing this, but it does make a lot of sense.

[tomp]

There have been many posted results of electric fan conversion dyno results. It typically nets about 10-25 horsepower. It's a no-brainer upgrade! These hp gains are at the wheels! Use Google

[[__--MUD--__]]

Originally Posted by twinmill28

What? The alternator is turning harder?
The alternator load on the engine will be the same regardless of adding accessories that draw more power,.

Ok...Dont get pissed off at me, but in my opinion your wrong. I wish you were correct as this completely violates multiple laws of energy. You would be rich man...if we could sell this

Your alternator will basically free spin when there is no load on it (it still will want to stop at a point). As your amp load increases, the power required to turn the alternator also increases. An alternator is just an electromagnet. The faster you spin it, the more power it puts out (disreguard the regulator and other bs for now). An electric motor is almost the same exact thing, but the process is reversed. The magnetic fields inside this amazing device are what creates this power, or movement if were talking about an electric motor. As the amp load increases the magnetic fields buld up and collapse. These magnetic forces inside the alt are trying to oppose this rotational movement. My AC/DC instructor liked to describe this like a magnetic compass needle always returning to North/South. The magnetic opposition strength increases as the amp load of the alternator increases (this is the load I'm talking about).

These guys w/ monster stereos that put multiple alts on their rigs 1) for more power, but 2) the friction force on the pulley only allows so much torque. At the super high draws they will lock up or severly slip on the belt. Solution- stay under the slip rating by adding an additional alt. You will strill drag the motor down, but not slip on the belt.

We had an ambulanse in autoshop the same week we were covering principles of electricity. This was one of the best examples as there is no free electricity. W/ the engine running, when all lights and accessories were turned on. The load was so high, it dragged the motor down to almost dying at idle, and any throttle above that just completely smoked the drive belt. They ended up putting two alternators on it, and bumping the idle up a tad.

If you took the pulley off a good sized alt and put a power drill on it, then engage a high load. The drill will either come to a stop, or the drills torque will snap your wrist off.

[guruerror]

Now I'm thinking about an electric fan...

I was reading through this thread from 05: http://www.elcovaforums.com/forums/s...=Electric+fans

Looks like the 2500 fans and Flex-a-Lite fans are the fans of choice...
http://automotive.flex-a-lite.com/ca...%3AHUMMER%3AH2

...or maybe I'll just leave well enough alone...LOL!

[[__--MUD--__]]

Originally Posted by tomp

There have been many posted results of electric fan conversion dyno results. It typically nets about 10-25 horsepower. It's a no-brainer upgrade! These hp gains are at the wheels! Use Google

I can see 10-15HP at the rear wheels on a 2wd setup. But now I'm talking about an H2 on an all wheen drive dyno. What do you think a realistic percentage is as far as what the transmission and entire drivetrain consumes? Thats what I'm really interested in.

Take that same 10-15HP, I'd be really impressed if we saw 3-5HP off that. What ever that comes out to, if you look at the $ per HP gain, I dont think it would be in a reasonable/justifiable. Take the cost of all these small net gain mods, and apply that money twards a supercharger or other large power adder, you'd be much better off.

Again i'm not disputing you wont get something out of it, but your not going to feel that by the seat of your pants in our rigs.

It good to see you back active across most of the forums. You were a little distant for a while there.

[guruerror]

Originally Posted by [__--MUD--__]

I can see 10-15HP at the rear wheels on a 2wd setup. But now I'm talking about an H2 on an all wheen drive dyno. What do you think a realistic percentage is as far as what the transmission and entire drivetrain consumes? Thats what I'm really interested in.

Take that same 10-15HP, I'd be really impressed if we saw 3-5HP off that. What ever that comes out to, if you look at the $ per HP gain, I dont think it would be in a reasonable/justifiable. Take the cost of all these small net gain mods, and apply that money twards a supercharger or other large power adder, you'd be much better off.

Again i'm not disputing you wont get something out of it, but your not going to feel that by the seat of your pants in our rigs.

It good to see you back active across most of the forums. You were a little distant for a while there.

...I hear you on that one. A little research on the fans has tempered my enthusiasm. LOL! $600+...even if you do get 25HP. That's like $24 per HP...at best. If you factor in labor to raise the cost and you actually end up netting less power it becomes even less attractive. At $800 with a 5HP gain you're paying $160 per HP...

Good logic MUD...