P400 Turbo Diesel 4x4 Dually

[rustyk]

I also got the Penisnsular 18:1, hi-pop injectors and a new IP (and the Phazer gear drive). Fuel economy is up from 9.25 mpg to around 11 mpg, and there's POWER there under the bed (diesel pusher motorhome ). And that's not "truck bed", it's a queen-sized bed .

[a5150nut]

and there's POWER there under the bed (diesel pusher motorhome ). And that's not "truck bed", it's a queen-sized bed .

But you have to make your bed, I can just hose mine out!

[JetBoater]

I just asked my supplier from WW Williams (Rod Townsend), what the compression ratio was in my P400. He advised it is 20.2:1

I also asked for the recommended maximum boost... he replied 28 psi at 2000 rpm provides max torque.

Is the 28 psi at sea level?

I am running 12 lbs of boost MAX at full pedal. Do I dare run a larger turbo and increase to these levels?

I am running the strongest commercial 6.5 available.... all comments welcomed.

Note: I will be adding an intercooler in next month or so.... and will dial in the max boost at that time. It should be broken in by then.

[DmaxMaverick]

28 PSI is a bit unbelievable, especially if it is a 20.2:1 engine. And, not knowing what turbo is in service, is well out of the efficiency range of most of them.

28 PSIA is 13.3 PSIG at sea level. Perhaps that's what he meant?

[JetBoater]

DmaxMaverick... I agree and have asked Rod for clarification.

I guess I am questioning why he would he give me a number that I would need to subtract the 14.7 psi of atmospheric pressure (101 kPa)...

I'll comment further after his reply. Thanks!

[JetBoater]

Rod just sent a reply and asked me to retract the 28 psi. An engineer at the Franklin Ohio plant will be providing more info after he looks into it.

[DmaxMaverick]

Oh, great. Now it really gets confusing. You know those engineer types

If you post the actual compression ratio and turbo you are using (as well as any other details you have), I'm sure we can give you a straight answer. The use/lack of a charge air cooler can play a large part, as well. Other than that, you'll have to run some trial and error testing (which you should do, anyway). Once you get some hard numbers, getting it dialed in is a matter of course. Fueling, temperature and pressure have to meet on common ground to get your efficiency target.