Lately I've been driving around with the Predator hooked up in the Real-Time Data mode and watching the happenings. I've noticed with my driving style I never really go above about 40% of the "engine load" (most of the time it's below 20%) I assume this 20% means that I'm only using about 20% of the available horsepower / TQ. So, on a stock truck with 300 available HP I'm only using 60 HP (20% of 300), Thus, the Allison is only ever seeing 60 HP put to it!??

Here's the question.......In theory, if I loaded a 120 HP program into my truck (now it would have a total of 420 HP) and never used any more than 20% of that available engine load (remember this is a theory :)) would the most HP the Allison ever saw be 84 HP (which is 20% of 420 HP)??

In other words, does merely adding extra HP hurt the Allsion in the long run or does actually using the HP cause the harm?

good question. i wonder the same thing, my pred is on 85 but i dont think it will do any harm if i drive like a grandma. dont know though, im interested to see what others with more knowledge and experience have to say about this.

Well, what got me to thinking was something that Steve Cole had said recently about "if you add more than 50 HP you significantly shorten the life of the tranny". I think I've only did the WOT thingy once to see how it did (don't tow much right now), so I'm just wondering if the wear and tear comes only after you reach that 360 HP'ish mark or if the difference in shift points in the programs causes wear and tear during general driving.

The problem is not the total power by itself. The TCM is pre programed with the power curve of the stock engine. If you increase the power above stock anywhere in the operating range the TCM will have to adapt to it. So far so good. The problem is that the TCM and the Allison only has so much range in stock configuration, big problem here. So if the program your using say doubles the power at 10% throttle the Allison does not handle it well.

The problem is not the total power by itself. The TCM is pre programed with the power curve of the stock engine. If you increase the power above stock anywhere in the operating range the TCM will have to adapt to it. So far so good. The problem is that the TCM and the Allison only has so much range in stock configuration, big problem here. So if the program your using say doubles the power at 10% throttle the Allison does not handle it well.
i sort of understand. dont wanna be a pain in the ass but could you say this again in a little more laymens terms? so running the truck around on the 85 at "average to normal" acceleration rates, rpms, etc will still be detrimental to the tranny, right?

i fully expect and plan to spend 4,000+ on a new upgraded tranny, but just dont want to have to do it for another 30,000 miles, about one yr., if possible.

I think what he's saying is.....the HP is not added at the end, it is added throughout the TQ curve. The TCM (trans computer) is not changed when HP is added via a programmer, only the PCM (engine computer) is. So, as an example - if stock, at 1/2 throttle position your trans is seeing 50 HP, then you increase HP via a programmer, now - at 1/2 throttle your trans is now seeing more than 50 HP and that's where the wear and tear occurrs.

Which makes sense...that's why the trans shifts so bad in every gear when you make a HP change - not just during high HP use.

understood, thanks for clarifying. only other thing is that since installing my predator it feel like the extra hp kicks in once your a little into the gear. it actually feels very similar to when the powerband kicks on on a 2 stroke motocross bike. am i crazy? is this normal? it doesnt feel like a bad thing.

does that reside with the edge also. I'm lookin at some info and it's sayi n the max end toque the trans can handle is 520. and maximum gearbox torque is 800. So if it surves me right our trucks are already at the max amount of torque it can handle right from gm. Ether the info i have is wrong or i'm not understanding sumthin. And one thing i've notices is that on the attitude moniter in my truck the slip doesn't change between level 1 and 3 the numbers stay about the same under acceleration. I too want to upgrade trans but it won't be for awhile. Un less i pull 4g's out of my butt or win the lotto.

Got a 2001 diesel pusher motorhome with Cummins 260 HP motor, and Allison 1000 five speed. Like to bump up the motor some, as it's only 520 ft.lb currently. I've read that the Allison won't handle it stock. Sure would be nice to boost it up to 300Hp & 600+ ft.lb. Ideas?


Ed