What is the effect on a Barth with a 190 hp upgraded to a 230, 250, or 265 hp with a 4 speed Allison.
Will I lose fuel mileage or be limited on speed? I will always be towing a light 4x4. Would I need to change the differential to even out the transmission gear ratio? Any opinions are welcome.

quote:

Originally posted by patrick mogan:
What is the effect on a Barth with a 190 hp upgraded to a 230, 250, or 265 hp with a 4 speed Allison.
Will I lose fuel mileage or be limited on speed? I will always be towing a light 4x4. Would I need to change the differential to even out the transmission gear ratio? Any opinions are welcome.

more hp might get you to cruising speed faster, but won't raise it.
5.9 w 190hp has ample torque to pull a toad without reducing cruising speed. I doubt the 0-60 even goes down much.
Dr. Yale pulled a Jeep tens of thousands of miles with a 5.9 190hp Cummins in 30' Breakaway (the one I had). The causes of two blown engines had nothing to do with towing or lack of power.
Changing the final drive ratio is going to screw up the balance of engine, trans and final drive.
ps
Expect 10mpg toad or no toad

Ditto what Mogan David said. The limiting factor on your Breakaway is the transmission, not the engine. These Cummins 5.9s do not like high RPMs ergo why there is a governor on them. In talking to Cummins engineers, I have learned that at 3100RPM, the engines will most likely begin to come apart which is why they also tell you to watch the RPM going down steep hills. If you want to cruise at higher MPH, you need a 6-speed transmission. But you would still need to watch the tach on downhill runs.

My question is what do you want to accomplish?

With the 542 you can go to 230HP. Speed will not be effeiticted. You will just get there slightly faster.

If your goal is to go faster you need to change transmissions. I upgraded to an Allison 2000 and if you check the archive you will find some write ups on this change over. Best thing I did to the Barth.

I also had it set up for 400HP for about 30 minutes and then backed it off to about 300HP. Might have upped the mpg a bit by no down grade. I now cruise about 70mph at 1800rpm.

Good luck.

Have the 190 and 4 speed, have to watch trans. temperature on long grades even with cleaning the radiators regular, IMHO increasing the HP (easy to do) would be pointless with out changing out the 4 speed. Buy the old song "don't worry be happy" and play it while traveling. were I wanting more power- I would sell this one and buy one with the upgrades, much easier and cheaper.