Engine/Transmission (1998.5 - 2002) De-rating an ISB Cummins

[SShan]

Can I de-rate the torque of an ISB 3. 9 4cylinder?

The torque is too much (420 ft/lbs), I would prefer 350ish ft/lbs.



About the torque de-rating. The torque of the ISB 140 & the ISB 170 is the same. If Cummins can bump HP from 140 to 170 while torque remains the same, I should be able to bump from 170hp to like 200 hp while keeping Torque the same, right?

Now to expand on this line of thought; could I raise hp to 200 and lower torque to 350?



Will I get worse or better fuel economy by de-rating the engine's power? What about durability and reliability? If the ECM is programed to inject less fuel then I will get better economy, right?

 

[Devan Manis]

you only inject enough fuel to keep you going at a constant speed or keep a constant acceleration, what im saying is decreasing torque will only help fuel economy if you constantly floor it every where you go, you are not always using 420lb/ft or torque, more likely its much less. loosen your throttle cable or put a block under the pedal, that way your full throttle is really only half? and you have to releard how to drive around your new "full" throttle.

 

[n7gxz]

The way Cummins does it is through a combination of injector size and programming in the ECM, I think more control is in the ECM.



Kevin

 

[Forrest Nearing]

you're way overthinking this...



just use a throttle stop

 

[Timbeaux38]

Why would one want to pull power out?