After about 9 months of working to get a 1990 cummins 6bt with a Allison 545 transmission into a 26' Champion RV. It's time to get it on the road. A VE pump 160 hp liquid to air intercooler. Would like to get 200 horse and as close to 20 mpg as possible. The motor has about 170,000 miles on it and never been tuned. Realizing this maybe a pipe dream but if you don't try you never find out. Looking to install a 3.07 rear diff to keep the RPM's down. Need to find out the sweet spot for a VE 5.9. Thanks in advance for any infro.

 

Don't know that you can get 20mpg in your rig... but IMHO 3.07 will get you the best mpg possible with that trans.

 

a at545 ... there is problem number one .. direct drive .. non locking .

Knew a guy with a bluebuird 92 12v at545 and it got 11 empty , 410 gears and 42" tires

 

Well for starters get a 3,200 rpm spring best $20 you will ever spend on that rig then do a 1/8" timing bump an m&h dinamic timing advance this is a good start to start with

 

Be sure to sure to know that with the ve pump no more then 15 psi the vp pump is way different