06 GMC LBZ AFTERMARKET TUNER QUESTION

[Badhabit]

For Christmas my family purchased a PPE Economy tuner for me. I have a completely stock 06 GMC crewcab duramax with the LBZ engine. Less than 125,000 miles. I have a choice of 3 tune levels 40, 90 or 120 hp increase. Stock it has 360hp/650 lb/tq. The tuner is not a shift on the fly type so I have to pull some fuses each time I change. I don't want to trash the Allison transmission so I'm wary of putting in the 120 hp tune. Anyone on here have experience with LBZ engines and tuners? How high of HP can I go over stock without messing a perfectly good motor up?

[dewandgin]

I know this not going to be the popular opinion but I have a 2007 Classic with a LBZ and unless I ever upgrade it, IE head studs, bigger turbo,Merchant Automotive Allison, etc. I would just leave it the way it is. Good power, good fuel mileage, and very reliable. I have 170k on mine and tow a 26 ft boat, mini excavator, 12k pound trailer and have never had a issue.
But if you must tune it then go no more than the 90hp. 40hp you probably would not notice and 120hp you might end up direct clutch issues.

[knighttime25]

I am in the same boat as you. I run the PPE Xcelerator Economy tuner on my 06 GMC crew cab LBZ (108,000) miles and currently have it on the level 2. I feel like it performs much better than stock and is a good balance between performance and overdoing it...been on a level 2 for three to four years now with no problems whatsoever

[Badhabit]

Thank you for the replies guys. Tuner was under the tree for me. I think I'll go with mid level 90 hp. Holy cow 450 hp and 800lb to torque should work just fine. I'll have to research the tire calibration option. I'm running 265/75/16 now and the onboard mileage calculator is off from the stock 245/75/16 tires.
Do I use the stock overall diameter of the tire or the "loaded" diameter of the tire and does it matter if I measure a "loaded" front or back tire?

[Zuus]

I have an ‘06 Duramax with a Diablo Predator which has 4 tunes. Tow, 40, 80, 120.
I have ran it on all settings. The 40 and 80 are my favorites, the 120 just seems to burn fuel out the exhaust!
Reason I put the tuner in was when I went to oversize tires, I lost hp and fuel economy. Tuner helped bring it back.
And it’s kinda fun every now and then. . . .
You’ll need to play with it to dial in the tire diameter. They’re not exact science.

[Woodchuck]

Thank you for the replies guys. Tuner was under the tree for me. I think I'll go with mid level 90 hp. Holy cow 450 hp and 800lb to torque should work just fine. I'll have to research the tire calibration option. I'm running 265/75/16 now and the onboard mileage calculator is off from the stock 245/75/16 tires.
Do I use the stock overall diameter of the tire or the "loaded" diameter of the tire and does it matter if I measure a "loaded" front or back tire?

Check your actual speed with a gps first, when I went from 245's to 265's all it did was take the factory error out of it.

[Badhabit]

it's about 2.5-3 mph off at 70. Speedo shows 67 GPS shows 70.

[HntnFsh]

Baby it for a few days so the tranny has a chance to relearn everything.

[scotsman]

Like a dummy I sold my 07 LBZ. Miss that truck...... i had the same tuner you have for about 80,000 miles with zero problems. I ran it on 40 hp boost 90% of the time. When planning on towing a 10K 5th wheel over the pass or to AZ I’d go to 90 hp boost.

[follow maggie]

it's about 2.5-3 mph off at 70. Speedo shows 67 GPS shows 70.

I’m sure That’s just natural error in the speedometer. My Chevy is off the same amount from gos with the stock size tires. Very few speedos are dead accurate.

[Badhabit]

Oh boy the 90 hp added some giddy up and go. Have not had a chance to "floor it" yet. Still trying to get the tire calibaration correct. I now have the tire diameter set at 31.25". Without load the 265/75/16's are 31.65" and the stock 245/75/16 are 30.47". I think each time I change the diameter I have to go back to the transmission "relearn" setting. Tomorrow should be fun getting this dialed in. I found that cell phone GPS speeds are not as accurate as a dedicated hand held GPS. Hand held does not bounce all around from 65 to 67 like the cell phone app. If anyone has a suggestion on getting the tire diameter corrected without having to go to tranny relearn mode let me know.

[HntnFsh]

If your towing on the +90 tune you better have a way to monitor your egts or it could get expensive real fast.

Heck I was towing 8000 last summer with my 06 lbz and caught myself doing 85 over Manastash and Vantage. That was with stock programming.seemed like plenty to me.

There are some good +40 heavy tow and+ 90 light tow tunes out there though.You just need to have a little common sense when you use them. I struggle with that when I have lots of power!

[Badhabit]

Heaviest thing I tow is a 20' Lund. I'm guessing it's right around 3500 to 4000 lbs loaded with gas, gear and the trailer. Biggest incline would be Ryegrass or the Quincy side headed east. The profile of the boat really kills the mpg's.

[HntnFsh]

Silverado Sierra Duramax forum has more info than a person could ever digest. Some incredibly knowledgeable folks on there.

[Badhabit]

I got it dialed in for the tire calibration. I had to go up to 31.5", tire size is 31.65" without load, so at 75 on the speedo it's showing 75.5 on the GPS. Kind of a pain to have to reinstall the tune and reset the transmission learn mode after every minor change of the tire size, but I got it done. Definitely still in the tranny learn mode.

[Badhabit]

Here's an update on the tuner. 20.0 mpg round trip from Yakima to Orondo, went over Blewett. 21.6 mpg round trip from Yakima to Olympia via White Pass. Round trip from Yakima to Finely averages 19.5. I'm very happy with the fuel mileage improvements and the performance improvements.

[Grit dog]

Like a whole new truck hey?
Excellent Xmas gift, you have a great family.
What I recall about the Dmax, had a LB7, was that the engine will handle pretty much any canned tune no problem (unless you're stacking tunes).
The Allison, while pretty robust, supposedly can't handle lot of extra power in the OD gear(s).

I never learned the hard way what the limit of the trans, but I also never got on it with a big tune in overdrive.
It would hold a "150hp" tune no problem up through 4th gear. Ran it at 90-120hp for 150k miles and the truck ran and shifted as good at 150k as it did new.