Help I bought a 1994 dolphin motor home it has a Cummings engine with a 4 speed Allison automatic. It needs more power, it has 12k original miles yes that is correct 12k had 9k when I got it a year ago. I have ground the plate disconnect waste gate, 4" exhaust with no muffler and upgraded air filter. it is better but not good I pull a 20 enclosed trailer with a 4 seat sandcar 1 quad tools and all the dessert stuff I need. When I hit the hills wide open its running 62mph 2300-2400 rpm 30 psi of boost and 1060 degrees on the pryometer. On the hills it just falls away end up in 3rd gear down as low as 29mph. Looking for suggestions considering a propane kit at this point I carry 42gal propane on board anyway looking for help..
Thanx Eric

 

That RPM doesn't seem right for the speed unless that thing has monster gears in it. Which it might, I don't know much about motor homes. I do know they go through the air like a giant brick, and between that and the trailer it's going to take a lot more than tweaking to get it to maintain a respectable speed on the highway without running EGTs in the red all the way there. A propane kit would keep the heat down but you aren't really making any, and if you were you'd blow through it in no time. You can probably run it in it's current trim for the rest of your natural life without any real engine issues. Or you can put twins on it and have it pull like a boss, watch your instruments like a hawk constantly and wait for things to start breaking. The job you're asking this engine to do, there's really no satisfying middle ground here.