Just wondering if any of you have bombed a medium duty? I run a freightliner fl60 with a 215hp cummins that I would like to upgrade a little. Any suggestions on a heavy truck pulling about 25,000 total weight all the time.

Thanks,
Jeff

 

First thing I would do is get gauges. I was going to try to get my work truck uprated (330 hp is available) until I saw the EGT under load. I don't have room for more power pulling a hill in the summer with a full load, so I'm stuck at 300 hp. Make sure you have some elbow room on the EGT gauge before you make any plans for more HP. I'd put a freer flowing muffler (racing muffler would do) and a resonator to keep it unrestricted but not too loud. It's not too hard to control the noise of a straight pipe cruising around in an empty pickup, but in a heavily loaded medium duty it's going to be loud all the time if you straight pipe it. (When the flex pipe on mine failed, it was ear-splitting under load. Sounded great to me, but that's just looking for a ticket.) Summit has the muffler, Berube's is a source for the resonator. If the EGT's aren't bad with a good load on the truck,get bigger injectors. An HX-40 would help keep the EGT under control, too. Is this thing a 12 valve or a 24 valve?

 

The ISB in these trucks is a medium duty engine and lots of these people here pull around that much weight often so I dont see the difference of application.