I have a duramax 2500 HD with the alison trans. I just recently upgraded to the Bully Dog Crazy Larry 3rd Gen.

The truck is working fine but i cant get the RPM above 3500. Is there anyway i can change or modify the vehicle to get better RPM output without doing major reconstruction fo the trans?

Not sure on updates but the Bully Dog is supposed to raise the rev limiter. Are you talking about during shifts?

you can change the engine tuning all you want, but the trans will shift at ~3300 rpm. It is pointless shifting higher on a stock engine because above ~3000rpm, the horsepower curve falls off fast.

you can change the engine tuning all you want, but the trans will shift at ~3300 rpm. It is pointless shifting higher on a stock engine because above ~3000rpm, the horsepower curve falls off fast.

not so.....When i tryed my friends PPE w/the rev limiter up to 4500,it was making some dam good ponys at 4k.

This is a LBZ issue so all you guys with your gay LLYs need to but out :p: ):h

It wont fule hard past 3400 RPM, the furthur you go past that the harder it pulls fuel. Its nothing that you can do. There are some hidden tables that start pulling requested troque when you get past 3400 RPM.

It sucks the big one for sled pulling :mad:

You can dry rev it all you want to 4k and beyond but it wont make power. I have jacked with EFI live a bit and with the help of some people got it were it fuels a bit better up there(compared to other things I have tried)......but its still not hte greatest.

It has noting to do with the trans holding and throwing parts in your trans wont make a difference.

not so.....When i tryed my friends PPE w/the rev limiter up to 4500,it was making some dam good ponys at 4k.
did you add any lift pumps or any other fuel enhancement over stock because on my 05 LLY even with a lift pump started falling fast when it hit 4k rpm's and at 4200 it was over for any power..on my mostly stock LBZ pulls hard at 3500 rpm's but any thing over that it needs more fuel and air to make it worth it..just my thoughts
"on edit" oops rat,i posted this and then i seen your post so you'll have to excuse the LLY thoughts..

did you add any lift pumps or any other fuel enhancement over stock because on my 05 LLY even with a lift pump started falling fast when it hit 4k rpm's and at 4200 it was over for any power..on my mostly stock LBZ pulls hard at 3500 rpm's but any thing over that it needs more fuel and air to make it worth it..just my thoughts
oops rat i posted this and then i seen your post so you'll have to excuse the LLY thoughts..

Pulls hard at 3400.....past that its all in the torque managment programing BS. Nothing that can currently be done about it for the regular Joe to my knowledge.

It sucks :mad:

many are working on this and hopefully we have a fix soon.

oops, I see were you just read my first reply :o: LLYs and LB7s you have it right....start running outa steam up there. :)

For grins if you guys with LBZs want to see this in action with a tune that supposedly raises the limiter.

Rev her in park or nutral. See what you can spin.

Now go out in 3rd gear and lay into the throttle and see what happens when you get about 3500RPM. Feel what happens and watch your boost and pyro.

not so.....When i tryed my friends PPE w/the rev limiter up to 4500,it was making some dam good ponys at 4k.

your SOTP meter is broken. ;) Every stock internal'd dmax will have dyno curves that fall off above 3000rpm.

Good luck running 4500rpm on that motor, you're going to need it.

many spin em hard. Ask tomac or john boy or about any other puller if they try to keep her at 3200 RPM in its "optimum hp curve" :p:

Could be a LB7 thing:p: but it pulled perty hard at 4k,i thought anyways,And no i do not have anylift pumps/fuel adders.

For grins if you guys with LBZs want to see this in action with a tune that supposedly raises the limiter.

Rev her in park or nutral. See what you can spin.

Now go out in 3rd gear and lay into the throttle and see what happens when you get about 3500RPM. Feel what happens and watch your boost and pyro.I did this in 4th gear without a liftpump and the power started fading around 3200 and steadily fell off up to about 4000 when I let off. I was thinking I may could run the 1/4 mile in 4th and be quicker because of fewer shifts but I don't think it will work.

yours falling on its face may be lift pump related as well.