I got a revised tune from them last Monday evening. Since then, I have put somewhere in the neighborhood of 400-500 miles on it. Seems that they have fixed the issues. The trans is holding each gear a good bit longer between shifts, which makes it so much more fun to drive. Now, when in 5th, it will hold that gear up till 70mph+ if I keep a little pressure on the pedal. If I want it to upshift, all I have to do is left off for a second. About as close to driving a manual without actually putting it in manual mode. Let’s you have more control over what it does.
Mileage-wise, I never really checked it before very much. The mileage gauge in the dash has always shown to be correct with hand calculations. So far, I get just as good as I did before. Last tank I got 12.6. That’s interstate to curvy 2 lanes. My throttle response seems a little better, although I would be happier if a little touchier. Jim III said Sr. warned that if he took the adjustment a little farther, that it might be too much when it tight situations like parking lots. But, I can live with where it is now.
Shifting is great with this tune. Smooth, quick, and precise. No hard shift, even after first loading it and doing a KAM reset. I have ran others in the past that would make you think the driveshaft was going to fall out.
On a longer trip this past week, I was on a 4 lane parkway and just sat the cruise on 83mph. Truck did awesome. Mind you, this road was hilly. Not super steep grades, but long rolling and down terrain. Not once did it downshift. Usually my experience when using cruise control is that likes to downshift on grades instead of holding the gear. Not with this tune. Can’t wait to tow with it.
At some point during the trip I observed the boost gauge hit 11 psi for a second or two before slowing dropping down. Not sure if this is a safe psi or not. Luckily, I don’t hot rod my tuck on a daily basis so I don’t believe it will be an issue. It would regularly see 5-8 psi when passing, etc. Normal cruising around will see it right at 0 to maybe -5 Hg vacuum. Seems like everything is working as it should.
If you’re considering a kit, I think you would be happy with the Whipple and JDM’s tune. Getting my first tune from them didn’t take too long, but the problem was that they never tuned it for my tire size, gear ratio, etc. I think that’s why the shifting was off and throttle response was lazy. They said they didn’t have that info in their notes, however provided each detail to Nick over the phone. Guess it got misplaced. My issue with them was it took 3, almost 4 weeks to get the revised tune. I was given a day to expect it, then told that something came up and they were busy. Well, they already had my money, so why be in a rush, right? Anyway, they finally came through. Speed is not their strong suit, but maybe that’s a good thing in the long run. I do feel like they know how to tune these trucks. But then again, for what they charge for the tune, you better be getting something.
