[RostyC]

Originally Posted by SteveBooth

Wow, from that graph you can do 1,550mph at only 70rpm.

Exactly, but I'm a little concerned about the high rpm number. (70) :lol:

[rank]

How exactly can I determine sweet spot from the graphs?

How about this one?
M11 Cummins 370/410 peak torque @ 1200 (from engine plate, not dyno)
4.33 rear gear
22.5 low pro
RTLO - ???13A trans

[allan5oh]

I don't plot out each engine.

But each engine has their own "sweet spot". For example, acert CAT's like 1325 rpms, detroits around 1400, etc..

Your m11 likes to be around 1600.

Tachs will always be some off. Mine is off around 50-70 rpms. Graphing allows you to determine exactly where you should be to get the best fuel mileage.

It also illustrates with ease what a tire swap would do.

[rank]

Originally Posted by allan5oh

I don't plot out each engine.

But each engine has their own "sweet spot". For example, acert CAT's like 1325 rpms, detroits around 1400, etc..

Your m11 likes to be around 1600.

Tachs will always be some off. Mine is off around 50-70 rpms. Graphing allows you to determine exactly where you should be to get the best fuel mileage.

1600 huh? I'm trying to remember what the engine plate says....I think it says peak Hp is at 1600.

[allan5oh]

I think it's around 1900 on those engines. Depends on the horsepower and year.

I'm pretty sure the sweet spot is around 1600. I'll do some research.