Towing 7000 lbs

[Allen]

I just bought a new boat! I just put 37's on and going from L.A. To Vegas...my H2 could only pull 37 MPH up the Cajon Pass The gas milage was 4.8 MPG at 58 MPH average

HELP - I am having the Voliant Air Induction systemw/ MFAS, Crane throttle body, Edelbrock ceramic headers, flow-master 3.5" exhaust installed next week. Will these mods really help? Should I go back to the 35" tires?

[Allen]

I just bought a new boat! I just put 37's on and going from L.A. To Vegas...my H2 could only pull 37 MPH up the Cajon Pass The gas milage was 4.8 MPG at 58 MPH average

HELP - I am having the Voliant Air Induction systemw/ MFAS, Crane throttle body, Edelbrock ceramic headers, flow-master 3.5" exhaust installed next week. Will these mods really help? Should I go back to the 35" tires?

[ROX]

Unfortunately, the tires aren't going to make a significant difference. The mods will help, but 7000 lbs is just a lot of weight for the H2. You were probably stuck in first gear at 37mph. I just pulled 3500lbs from Portland to Yuma , and averaged 54Mph over 1280 miles; avg 7.4 mpg. Ouch! I run the flowmaster and 35 inch tires. (these numbers are confidential and should not be shared with any trolls from fuh2.)

Take the radiator cap off and drive a new Duramax under it and put the cap back on. That will fix the problem.

[drmiles]

Super Charger. Also if you have not recalibrated you speedodometer your probably doing better than you think

[Allen]

Got the shorty headers on, Flowmaster exhaust, Volant Air Induction system, throttle body spacer put on and went ahead and put the 35'sback on. Hope it helps towing and mileage. Anybody got a guess as to the additional horsepower gained through the mods I made?

[drmiles]

They all claim 10 - 15 hp. It'll help but not enough to pull 7,000lbs up hill. Good luck keep us informed as to the results. I recently ordered but have not installed a supercharger, for the same reason, 7,000lb trailer. However the only hills around here are overpasses. but still struggling to stay above 60mph and stay in 3rd gear. It wants to run in 2nd above 70 mph.

[Allen]

I drove my H2 on the freeway today with the mods on. I do feel a nice difference in acceleration after 20 MPH. More midrange pull. I tow the boat back to Vegas tomorrow. I will report back.

BTW - I saw an H3 today at the Magig Mountain Exit. Going onto the Old Road. It was White and had Black plastic all over it to disguise it. Small Rig!

[ROX]

Why don't you try one of those aftermarket programmers? You can always change the program back to stock when you take your rig in for repairs at the dealer. I think that's what I'll do, and add a bigger tranny cooler for pulling in hot weather.

[PARAGON]

While I haven't pulled a significant amount of weight since I changed over to 37s I don't it's going to be as noticeable as you think. The H2 is just not designed to be a good hauler. If you don't expect much out of it, have some experience pulling trailers and are not worried about keeping up with traffic all of the time, it's fine.

I do have the programmer and that is the single best improvement short of turbo or supercharger one can do. You can really dial in the shifts relative to speed or RPM. The oddball shifts the stock tune had even in tow/haul mode makes you lose momentum too easily.

In deference to H2Rocks, (with stock tires) I have pulled around 10K lbs total weight about 145 miles with the H2 and 8K lbs over a 4 hour trip and never experienced a tranny overheating issue. And that was in the summer here where it's in the 90s during the day.

After everything I have found out over the last few weeks, if I wanted a mod just to make towing better on the H2, I would probably go the turbo route and that Squires System would be a consideration if I didn't take it on the trails.

Allen, anything that helps it breathe will be a good thing. My biggest issue between 35s and 37s would be stopping more so than anything else. That would be less of an issue if the trailer had electric brakes though.

[ROX]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PARAGON:
In deference to H2Rocks, (with stock tires) I have pulled around 10K lbs total weight about 145 miles with the H2 and 8K lbs over a 4 hour trip and never experienced a tranny overheating issue. And that was in the summer here where it's in the 90s during the day. </div></BLOCKQUOTE>
It's been my experience, that in hot weather over long trips,(yeah, it gets hot for a couple of weeks out of the year up here), going up and down all the hills and passes, that the tranny gets hot enough to make it start shifting funny. I mean, it's always in second pulling hills and shifting to 3rd on the top, but when it gets hot, it takes longer to shift back to 3rd. Is this making any sense? The temperature is running hot, but not at the orange mark. I changed the fluid after that at 30k miles and was told it didn't look burned. I thought installing a bigger cooler would help these issues.
P.S. WERE YOU PULLING 10K LBS WITHOUT TRAILER BRAKES? SHAME! SHAME!!

[PARAGON]

Well, I can't say that we have much more than small hills around here. No long extended grades to pull up.

And no way did I pull 10K lbs or even 8K lbs w/o electric brakes for any extended miles. I don't have a controller dedicated to My H2 because I always think I won't pull that much because we have 2 3/4 ton pickups and my Denali XL that pulls much better. Each time I know I am going to pull that much weight I pull the controller from the Denali and temporarily install in the H2. That's not to say that I haven't pulled the tractor (10k lbs including trailer and equip.) 10-15 miles without the controller installed because it was a spur of the moment thing.

I haven't permanently installed a controller because there is no good place that doesn't hit a knee or something. I'll end up mounting one some day when I decide where I want to put it. I have been thinking of dremeling a hole in some portion of the dash if I could figure a way out to finish the edge of the hole.

[Allen]

Ok, 568 miles pulling 7000 lbs. My mods worked GREAT. Gas mileage up to 7.0 froim 4.7! Average speed 56 MPH. LA to Vegas on I-15. By going to 37's in inadvertantly (in effect) changed my gear ratio from the 4.10 to 3.73...i did the math. Going back to 35's helped. Befor Mods, My H2 would hunt between 1st & 2nd. Now it stays in drive & 3rd and 2x's into 2nd. Never 1st!!!

Big improvement.

NOW - the Tranny cooler. Any ideas???

[ROX]

Really? That much of an improvement?
I know how the exhaust helps performance, but could you please explain how new headers and throttle body help? please. Be specific.

[Allen]

I havent a clue. I just work here. Seriously, I am methodical about numbers and figures. I reset the trip computer before and after the mods

[Allen]

BTW - don't forget the Volant Cool Air Induction system & MAFS

[ROX]

MAFS? Is that Modified Airflow System? I had an Airaid intake system that was so lousy I'm leary of anything else. I have seen the Volant on a showroom vehicle and it looked like it was sealed against the elements better than the AirAid. I know on a diesel truck the next best thing for hp is a larger exhaust w/out the muffler. In some places the cat can be straight piped as well. I'll reset my trip meter again when I leave Yuma and see how good the mpg is going up the map back to oregon.
I'm thinking I'll put a different filter in the stock box and see how that goes before I buy another intake system.

Send pics of the boat! And the H2.