Need advice for more power and lower EGT

[TLowery]

I have a non-intercooled Cummins 6BT out of a 91 Dodge in my M-715. The engine is stock early 91 hooked to an 96 NV-4500 trans. I have 4. 56 gears and 42" tall 11R22. 5 "big rig" tires on it. I will be swapping in a Dodge 205 in the future. I plan to twin stick the 205 so I can occasionally use rear-low like a gear reduction brownie.



I am looking to get more Ooomph for towing. My EGT climbs awfully bad on grades and I have to back out of the throttle to keep the temp down. This is where I need the advice.



At the moment I am running a K&N filter attached directly to the turbo which I am getting rid of and replacing with a hood mounted, canister style air cleaner.



I used the stock down-pipe, but it bumps to 4" right after it makes the 90. I run 4" all the way out the back with a Dynomax 4" "cherry bomb" type drag racing muffler. I think my exhaust is good, so I shouldn't have any problems there. But, you guys are more familiar with this stuff than I am.



I would like to add an intercooler, but to fit my grill I will either have to have one custom made or really modify the radiator support to accept a Dodge unit. What CFM rating is required for the Cummins? How much does an intercooler help power and/or EGT?



I am running the stock turbo, would a different turbo be better?



I am thinking about the "old blue" injectors I have seen mentioned here on TDR. Also thinking up having my pump timed and "turned up" a little after the injector swap.



Sorry if this is a bit long, just looking for some ideas/information. I have been and will continue reading through old posts for info. Any recommended threads?

 

[Power Wagon]

Your earlier engine has pretty good flowing injectors. If this is the engine with the 9 mm tips, then you're in pretty good hands now.



One of the things you could probaby do is to advance the timing a little bit. This tends to drop the EGT a little and improve the performance.



Putting on an intercooler will help, as well.



I would be a bit hesitant to push one these engines too far in the HP department, as some of the heads tended to crack in the earlier engines.



Also you might want to try out a castoff 12CM wastegated housing, and set the wastegate to the minimum amount of pressure reqired to have tolerable EGT and/or clear up the smoke.

 

[CToney]

Intercooler

If finding a air to air intercooler that would fit is too tough. Maybe look into a air to water intercooler off an industrial or agricultural engine. The air to water rise a little above the valve covers I think so you'll need a little bit more hood clearance. also injector lines might have to be changed but it might be worth looking into.



Hope this may help.



CR Toney

 

[Lil' Dog]

Ctoney is on the right track, I have seen alot of gas plant fire water pumps with 6BT's and the air to water cooler. Its worth a shot!



J-eh