isb 300

[codybones0]

I was wondering if any one knows how much I can pump up the power on a isb300 cummins without damaging the Allison 2500 transmission I could definitely use a little more power

[Stever53]

this place is great

Can't help with your question, but scroll down to
Power train garage forum, you might have better luck there.
Good luck

Safe travels

[bamaguy911]

Originally Posted by codybones0

I was wondering if any one knows how much I can pump up the power on a isb300 cummins without damaging the Allison 2500 transmission I could definitely use a little more power

We had a Monaco Diplomat, 1999 model with the ISB 300. I installed the BANKS system on it and had good results. Banks claims a 40+ HP gain (don't remember the torque increase, but the increase in "get up and go" was pretty impressive). I do remember that the added torque was still below the Alison specs.

[onechaddude]

Originally Posted by codybones0

I was wondering if any one knows how much I can pump up the power on a isb300 cummins without damaging the Allison 2500 transmission I could definitely use a little more power

I have an 07 Neptune with Cummins ISB 325hp and Allison 2500. A couple years ago I decided I'd like a little more oomph. After a good bit of research I decided about the only option was the Banks power kit. I installed it myself. Worst part is drilling the exhaust manifold for the egt probe. This is definitely required for any engine enhancement. The Banks is ordered specifically for the transmission you have as it protects the tranny unlike lots of other programmers.

The Banks kit really helps my coach. It gives enough extra juice to cruise up many of the hills that used to require downshift to 5th gear. I can't remember the exact amount of power they claim it adds, but it's definitely noticeable. I'm also surprised at the temp the egt usually runs at. They claim 1300 or 1350 as max. I rarely see anything over 1200 df. Usually the highest egt temps come when you're lugging the engine.

If you have any other questions just let me know, I'll be glad to answer or help anyway I can.

Chad

[codybones0]

Thanks everyone I think I'm kind of torn some people are saying the motor is matched really close to the tranny so adding HP might cause damage to the tranny over time I think I'll keep researching and chugging along for now but still welcome more opinions because I have no Idea

[Winemaker2]

If I'm not mistaken Freightliner uses Allison 2500 w ISB up to 340 HP and (think) 600 ft.lb torque. They go to the A 3000 w ISB 360 HP & 800 ft.lb.
You might talk w FLiner or Allison and see if they will provide any insight or advice.
Allison specs should spell out limits pretty clearly...and I think it will be torque based not HP.
It might mean a reprogram of Tranny as well but that shpuld not be a big deal unless I'm off base...????

[FleetMan]

My long time, trusted Cummins Rep researched this question for me shortly after we took delivery of our ISB.02 300/2500MH rig. His advice was to not "pump up" the engine because of the torque input limitations of the transmission. Adjust your driving to that power train and you should not have any problems. You will never be the fastest one going up the hills but you won't be the slowest either.

[bamaguy911]

Allison MH Transmisson Info... RV - Motorhome

[asuperheat]

You can take it to a dealer and ask for a uprate. They will do what it can handle without damaging parts. The year and if you have tq management depends if they can help you or not. They had to have freightliner tell the shop what it could take and what tune to use. Its not like some guy in the shop just goes in and turns it up x amount. I had mine done with good success, I have the 2100 and ended up with 315/750. I believe the newest 6.7/ 2500 from the factory are 340/800 tq. from some of the builders. Mine originally was 300/660. Tq is what you are after.