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View Full Version : 08 cc sb 2500 need more power for towing



dins1
03-16-2010, 17:17
what is the best and safest programer for the LMM I want more horsepower on the road towing a 36 fifth wheel camper

Mark Rinker
03-16-2010, 18:39
My .02 worth...

While I haven't towed with an '08 yet, I am of the opinion that the LMM tune is pretty healthy from the factory, is encumbered with regen emmissions equipment that is sensitive to smokey tunes, and that the transmission/TC has a more narrow margin before converter slippage can occur, when compared to your other Duramax powered trucks listed. The LBZ and later engines are probably best left in stock trim for towing duty, at least until your factory warranty is expired - if you want to have warranty coverage in the case anything breaks, that is.

That being said, the best tow-designed tunes are those tailored specifically for your towing needs, and a custom ECM based tow tune from Kennedy Diesel can certainly make that happen, and is the hardest for GM repair shops to detect. Again, my advice would be something on the way-tame end of the power spectrum, maybe 30-40hp.

An opinion, your results and risk acceptance may vary. Always carry your stock ECM, programmer, or whatever so you can return to stock setting, if the need arises.

richp
03-16-2010, 21:00
Hi,

I tow a 34' Jayco fifth wheel (12.5k pounds) with my stock LMM. I've towed it a lot between Illinois and the West coast. It's pulled the Rockies a number of times, in addition to many long uphill pulls on midwest and eastern hills.

Seat of the pants impression -- theLMM's stock performance is equivalent to what I had in my LB7 with an Edge Juice towing the same rig. The newer Allison is, in my view, far superior when it comes to downhill control.

I understand that different folks have different views of what's desirable in terms of power. But when I can pull Vail or Eisenhower passes on I-70 west of Denver at the speed limit, I fail to see why I would ever need more power. To me, the real limiting factor on hilly highways like that is the traffic around me -- not how much higher I can push my EGTs.

FWIW.

Kennedy
03-17-2010, 07:40
I'm in the process of developing a Tech Tip page describing LMM details, pifalls, etc.

Essentially what I recommend for the LMM is an ECM swap so the stock ECM is "virgin" or you WILL have warranty hang ups down the road. From there it depends what you want to do with exhaust etc.