hp/torque when towing

[J&LRam]

does anyone have hp/ torque numbers at 50%,60%,70%etc. throttle as compared to wide open throttle, or a web site with charts. The numbers i need would be when i'm towing up hills and don't need wot. Got a gas/diesel argument going with some 8. 1 GM guys. I've seen charts showing our Cummins idles at 350+ ft lbs but every thing else is at wot... ... ... ... Thanks... ..... JIM

 

[KevinO]

go on a chip manufacturer website and look at the stock dyno charts. There is no #'s that i have seen for part throttle

 

[JNutter]

Make sure to mention to your gas guzzling buddies that they lose 7% of their power for every 1000 ft gain in altitude, due to the loss of barometric pressure.



Diesels hardly notice the difference in altitude for a couple of reasons. One is that our engines just plain flow better than a gas engine. The second is that we presurize our instake system. I've heard it's around 24 psi on our trucks stock (someone with gauges please correct me if I'm wrong), but I don't have my gauges in yet (next week). 14 psi is one atmostphere and that's the most their gas engines will see even at sea level, without a supercharger. Ours see that 14 plus another 24 or so on top of that at sea level.



Here's an example to show them. A guy on the board with the same engine, transmission and gears as I have dynoed his truck in Ft Collins Co. I looked around the 'net and found that Ft Collins is at about 5000 ft of elevation. Here is his run: https://www.turbodieselregister.com...?s=&threadid=82909&highlight=dyno+AND+results



I dynoed mine in Minneapolis, at about 1000 ft of altitude. Here is my run (follow the link in the post):

https://www.turbodieselregister.com...?s=&threadid=84037&highlight=dyno+AND+results



Note that his UNCORRECTED power was the same as what I got. My oppinion is that you can ignore altitude correction factors for diesel trucks, because the altitude just doesn't make as much of a difference as it does on a gas engine, and these factor were invented for gas engines. My point is that when you're in Denver, you will still have all the power you had at sea level, but they will be down to about 70% of what they had at sea level.



One other data point from my personal experience, I used to have an old F250 with the 7. 3 ID TD. This was a pre-powerstroke engine and it only made 5psi of boost when it was stock. Even with a lowly 5psi of boost, I could not detect any power loss until I was at elevations over 6000 ft and then it fell off a lot slower than the gas engines around me. Mileage didn't drop until I got above that altitude as well. Meanwhile, people I was traveling with that had gas engines could blow past my old truck in Nebraska but couldn't even come close to keeping up through Wyoming - and their mileage went in the toilet at the same time.

 

[Camp]

Well, I can tell you that my Duramax, that is for sale, spanked an 8. 1 Avalanche on our pull to Moab last year. I had a lot more weight, better milage, and less power loss than him running from Denver to Moab.



By the way, my Cummins 600 is on order, hense the Duramax for sale.