2006 Duramax LBZ

[dadams]

I have my Predator tune set on 85 HP and it sometimes boggs out and blow black smoke apon acceleration. This happens almost every other time around 40-50 miles per hour. The next time I hammer it it doesn't do it. If I set to stock tune I don't see the problem. Fuel filter only has about 5k miles and this is not the first time it has done it. K&N cold air with about 3k on cleaning.
What do you think?

Doug

[mikel]

sounds like you are slipping the transmission a bit...