I have a 1996 32' Monaco motorhome with a Cummins 5.9 230hp-BTA diesel. I
have replaced the stock(catalyst)muffler with a Magnaflo 4" muffler and have
DDP-1 injectors and a Banks quick turbo exhaust 14mm housing and I have
blocked off the wastegate. I only get 30 lb boost max with no leaks. It is
a stock modified plate(filed off the bump out) .040 forward from stock. It
runs 1200-1250° wot in 4-5-6 gears, warmer in lower gears.
My question is that everything I've done so far has helped the power some
each- but no magic bullet.
I think the problem I now have is with the down pipe to the exhaust
brake(works). It is 3" OD and is 2' long- everything including the brake
back is 4". I also have a 3GSK installed. Timing is stock at 12.5°.
What do you guys think- is the 3" down pipe my problem? or not? Or what?
Thanks for any help.

 

It would help a bit to make that 4 inch since the brake and back is 4. Also i would say a timing advace would be your biggest bang with all the other mods. Another thing you should watch is your cooling abilities. With all the upgrades you have to monitor your coolant temps, if they get a bit higher than normal you should upgrade in that department.

 

Come on guys, A cummins is a cummins whether it is in a truck or motorhome. Can anyone answer this?

 

did dieselrob not answer it or something?

 

timing to 15 or 16 will help alot. mover your plate all the way foreward and slide the afc housing foreward a bit also. do a search on how to tune the afc housing. do a high flow air filter if you already havent. but i think you will find if you move the plate foreward you will see more fuel. not sure where the efficency of the charger is but i would guess arround 40# of boost.