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H1 Hummer Cummins Swapped

Scholioso said:
Ok awesome. How do you determine the correct size pulley you need? I'm guessing I wouldn't be able to just bolt the cummins 8 rib pulley onto the 6.5 alternator?

I was running a cs144 on my 6.5. Should I stick with that or change to something else?
Click to expand...
Did you ever get the pulley diameters figured out or?
 
@LowRam Hey, saw your shop became vendor on hummer forum- makes sense with all the hummers you guys do already.

Any new toys you been playing with to share?


@Sand not being able to work on mine, I am living vicariously through your build, and superlady’s adventures right now. Haha. Did you do anything different with your radiator or just run same one for now with the fan change and see?
 
Maiden drive. 12 am. No dash.
Megasquirt trans controller is not working yet. Emailed their tech dept. Limp mode. 2nd and reverse.
Had it in low range by accident and it seemed odd that limp mode was 1st grear.
Cant get the megasquirt to be seen by the laptop. Hope to hear back shortly. 56081
 
Project has moved along! A few leaks, blew off a turbo clamp at 30 psi (scares the Dickens out of you! Lol) and alternator plug the didnt click in which sacked the batteries twice.
After 2 days of light road testing I hitched up a 5k trailer and drove 900kms. Through the mountains... not recommended as a routine but I got away with it. Temps never crossed 195. Boost hits a little over 30psi at times. My pyro is post turbo and peaked at 1k briefly but lives in the 600 - 800 deg zone.
Its clattery and noisy but so are hummers.
 
The transmission was an easy fix. In the tunerstudio software setup I had selected the wrong hardware version.
The support from megasquirt was awesome. I was initially questioning their routine of email support only - no phone calls....but they are really quick to respond and know exactly what they're talking about. Plus with an email you can follow the diagnostics they suggest carefully at leisure - instead of a phone in one ear a tester in both hands and a diesel idling 18" away. The standalone controller works right out of the box after you do the setup but now the fine tuning begins....
 
I have new respect for transmission tuners...
It's not as straightforward as it seems. A Hummer is about 7500 lbs, the final drive reduction is almost 5:1, tires are 37" stock. It makes for a weird setup.
The H1 spends most of it's time in 4th gear.
Torque converter Lockup seems to make the best boost and allow the truck to climb past 60mph. Otherwise 4th gear just reves the engine, with low boost and no gain in speed. But the converter locks up and then the whole machine just drones endlessly at 50mph like its lugging (but its not really at 1800 -2000 rpm)the engine and building egt's. If I pound the throttle it leaves lockup, but reves without making power or gaining speed...,,
I'm playing with speed parameters on when lockup engages and dissengages and at what throttle position (% of tps swing) it engages and dissengages as well.
I'm missing something...It's never right.
I'll post screen shots of what I've set up to see if anyone notices a glaring error. Or it may be pressure curves on the gear setups I have off. I've not been brave enough to touch those yet...
 
Sand said:
I have new respect for transmission tuners...
It's not as straightforward as it seems. A Hummer is about 7500 lbs, the final drive reduction is almost 5:1, tires are 37" stock. It makes for a weird setup.
The H1 spends most of it's time in 4th gear.
Torque converter Lockup seems to make the best boost and allow the truck to climb past 60mph. Otherwise 4th gear just reves the engine, with low boost and no gain in speed. But the converter locks up and then the whole machine just drones endlessly at 50mph like its lugging (but its not really at 1800 -2000 rpm)the engine and building egt's. If I pound the throttle it leaves lockup, but reves without making power or gaining speed...,,
I'm playing with speed parameters on when lockup engages and dissengages and at what throttle position (% of tps swing) it engages and dissengages as well.
I'm missing something...It's never right.
I'll post screen shots of what I've set up to see if anyone notices a glaring error. Or it may be pressure curves on the gear setups I have off. I've not been brave enough to touch those yet...
Click to expand...
Sounds to me like you need a better torque converter. My torque converter (that had maybe 15,000 miles) was fine with my 6.5 with as much fuel as the DS4 could give it. Then I put the hot DB2 on it and I hate the converter unless the converter clutch is locked. I’ll be getting a new converter in it before it gets back on the road. I think you are experiencing the same thing now that you have more torque available.
 
Sand said:
I have new respect for transmission tuners...
It's not as straightforward as it seems. A Hummer is about 7500 lbs, the final drive reduction is almost 5:1, tires are 37" stock. It makes for a weird setup.
The H1 spends most of it's time in 4th gear.
Torque converter Lockup seems to make the best boost and allow the truck to climb past 60mph. Otherwise 4th gear just reves the engine, with low boost and no gain in speed. But the converter locks up and then the whole machine just drones endlessly at 50mph like its lugging (but its not really at 1800 -2000 rpm)the engine and building egt's. If I pound the throttle it leaves lockup, but reves without making power or gaining speed...,,
I'm playing with speed parameters on when lockup engages and dissengages and at what throttle position (% of tps swing) it engages and dissengages as well.
I'm missing something...It's never right.
I'll post screen shots of what I've set up to see if anyone notices a glaring error. Or it may be pressure curves on the gear setups I have off. I've not been brave enough to touch those yet...
Click to expand...
 
I'd bet the torque converter has to high of stall, on a Cummins as you modify for power for a DD the stall speed should be lowered ans yes there are arguments to the contrary however; the torque curve of any cummins is much different than the 6.5td v-8.

I run a 1.2k converter and when its locked I stomp on the throttle and it stays in lockup and the Burb just halls a_s, then again it's a highly modified 47RH transmission.
 
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