I was just wondering what would be the max RPM for my stock 5.9 Cummins? Everything is stock except my 70HP box, intake, and exhaust. It builds boost so quick that I have to really keep my eyes on the tach. But, sometimes I get caught up looking at the smoke in my rearview mirror while Im banging the gears. Just kidding! Well, maybe sometimes.

Anyway, I just don't want to blow my engine because of to much RPM. I usually shift at 3000 RPM and that seems to work ok for me keeping my boost up. I may even be able to go higher with my shift points. I didn't know if there may be some type of safety feature in the computer to keep the truck from over revving.

Any comments or suggestions are greatly appreciated.
Thanks, ERIC

 

I would not go to much past 3200. You would probably safe running 3500 Rpms a few times. This is what happen when you run high Rpms with high boost. Nothing serious but to many times will be bad.
https://www.dieseltruckresource.com/...ght=head+today
I don't even think the chip you have will fuel much past the safe point anyways. It takes alot to spin mine up to 3800. If you get 60 pounds valve springs you'll be safe up to 4k.

 

Thanks a lot. I will keep my eye on it for sure now. Im sure you're right about my chip. I don't think it will fuel up to 3500 RPM, but I know I have been close to it at least once. Matter of fact, I need to quite playing like it's some kind of race truck or something.

 

the truck will fuel too 3500 with a programmer like the smarty.....but as loing as your boost is less than 45 psi....3500 is safe. Anything more than 45 psi and I would go anything over the 3200 rpm redline set out on the tach.