MAX RPM

[motoboy549]

im new to the idi and actually diesels too. i see a few of yall having stuff bout ur truck doin like 4000 rpms and some people further in ur sigs. my truck drops off at like 3200, maybe even a lil lower. My truck is stock well i ripped off the exhaust other than that stock should it be droppin off that low?

 

[rupejosh]

i personally wouldnt take my motor that high but i also dislike rebuilding motors.lol

 

[65sixbanger]

the 7.3 pumps should be limited to 3800, and the 6.9 pumps are limited to 3200, unless the springs have been changed. In all honesty, my motor runs so smooth at 3800.

 

[97idi]

MR DYOUNGS 4400 rpm seem like the motor has a million dollars in it its ultra smooth

 

[dyoung14]

as pumps get older somtimes they will not wind as high as the use to, 3800 is were everyone of them should be set at, heck 4000 is even smooth on these engines,

mine even feels real clean and smooth at 4500rpm, but anything over 3800 do it at your own risk

 

[FordGuy100]

Like said, they were set at differenet specs. IH application's used 2800rpm limiters as well.

As the pump reaches its limiter, it defuels. Thats why you can feel the loss in power. I can see it by the boost gauge. When the wastegate was hooked up, I would get to 9psi of boost and hold it till about 3000rpm's, and it would slowly drop off to around 7psi. My theory is that it defueled as it got closer to the limit (3300rpm's) and my boost dropped because of less fuel.

 

[dave186]

I rarely see 3000 with mine, no need to wind her that high with the turbo.

 

[1320Cummins]

Both of mine will turn 3800 no load. I generaly shift the S-1600 at 2500 loaded and around 2200 unloaded. I did put it on the floor pulling out of a pit today. 1/4 mile or so of steep, soft, rutted ramp loaded at 30,000+ lbs. She was screamin away at ~3300. And they told me my single axle wouldnt make it out of there I must admit, I was not sure if it would or not. I am certain that without the turbo it would not have made it. I was limited to 1st high range 2nd low would quickly lug it down. You should not need to wind it past 3000. Your motor makes peak torque at like 1600rpm.

 

[fuzzydog]

I must be getting old. Mine never sees the high side of 2500.

 

[Agnem]

I must be weird. I'm always trying to figure out how to make mine spin slower.

 

[f-two-fiddy]

Mel

I'm in the same boat!

 

[rckslash2010]

Mine rarely see's 2500 also, I think it's a bit much. But then again I think my tach's off 200, cause it says I idle at 450. When I run it at high r.p.m's I can watch my fuel gauge drop right in front of my eye's.