[Archived]

I had a Country Coach with a Cummins ISL. 400. PDI worked on it, 480 hp to the ground. My main objective was fuel mileage. 70000 miles later I mite have gained two to three tenth. The $1,200 was not worth it. Pulling a Liberty four wheel down, had a little extra on the hills here in the west, but had to watch the water temp. Colorado hills had to back off to keep cool. Two friends with C13 Cat and ISX 500 Cummins both PDI customers, had to watch the temp. Yes they did gain power, but no increase in fuel consumption to justify the cost.

I do not know but checking with Detroit, to make sure everything is set correctly, could be a more reasonable way to go

02. XLII Vision

12 CRV Honda

[Clifford]

Clifford, I don’t know the exact answer to your question. I have a good
friend that tunes 12.7s every week. Tuning Detroits is his main
business. He will not accept an ECM in the mail, he only tunes trucks he
can drive and evaluate in person. He says about 7% more fuel on a stock
500 HP 12.7 is the max if you don’t want some type of over heating
problem. My experience has been that DDEC V 14 liters will stand a
little more but not much. What does that equal in HP? I don’t know.

As
pointed out by Jon tuning a Diesel engine for performance and or power
is complex with no free lunches. More power, more heat, it’s just simple
physics. Read the link, it’s for the Duramax but it’s the same for our diesel engines. It’s the simplest explanation of the
facts I’ve every found. You can’t just add more fuel and expect optimum
results. Although adding fuel, at least up a point usually does help performance and mileage but it’s only the start of a good perfromance tune.

G-man does your Duramax seem to run any hotter under a heavy load on one of the higher settings?

http://killerbeeperformance.com/download/tuning/Timing%20the%20Diesel.pdf

Ken