tuning question

[ptlogan77]

First Trip Update!

I downloaded the corrected ECM files to my truck an took a short trip from the coast to Spokane and back. (about 850 miles round trip with a lot of hills)

First impressions are:

Obvious higher useable RPM range.
Was 1100 to 1500 RPM, Now 1400 to 1800.
Sweet spot for pulling is 1500.
I pulled Snoqualmie Pass at 1500 RPM and the pyrometer sat at 900 steady, @ 32lbs of boost MAX.
Tried 1600 RPM, and pyro would climb to 1000.
At 1700 on a hard pull I could get 1050.

So, I'm sure that were on the bleeding edge of too much boost, but what a pulling beast at 1500 where before you'd have to lug it down into the Basement Beating RPM's.

The pyrometer acts the same as before...the higher the RPM the higher the EGT's, but for my money this setup works great as I can pull any hill at 15-1600 and not be concerned as much about the lower end getting punished and the EGT's stay at a comfortable level.

The hills I pulled with the same load as last week I pulled at 8-10 MPH faster and a half gear higher than before, so I cant give an accurate fuel mileage update yet, but when cruising on the flat stretches it used far less boost to cruise, and the current fuel mileage data showed a vast improvement from before.

No tune is going to make up for the 3.25 rear gears that I have, or the large flat grille I'm pushing down the road, but to say that I'm anything less than extremely pleased with the changes done to the tune would be unfair to Rawze, as he has found a few tweaks that effectively move the functional RPM range of the engine up to a safer, more useable area with no downside noticed.

If the original tuner was to apply some changes to his tune raising the RPM range and decreasing the low RPM fuel load along with fixing the derate issue, (there is obviously far more available power now) I believe that the liner pounding, block fretting tunes could eventually just be a bad memory like so many other tricks we've tried like backing off the aneroid, the green and yellow spring, and over-shimming the pump...Live and learn!

I'll be interested to see the fuel mileage numbers next month when I start traveling to Northern B.C., where there are some LONG stretches of flat road where I can get some real information on flat ground mileage.

Thanks to Rawze for looking over my tune and making some minor adjustments that when put together made a major improvement!