Good RPM range for my truck - Diesel Forum

BCbinders · 11-26-2005, 10:33 PM

Hello all [img]/ubbthreads/images/graemlins/smile.gif[/img]

Well I got my tach working and now I am wondering what is a good range to stay in for RPM's? What is the highest I should go (not that I am going to try to redline it, but still it would be nice to know [img]/ubbthreads/images/graemlins/smile.gif[/img]

I remember with my all the IH's that I have owned they really aren't high reving motors, and all the more heavy duty IH's that I have driven they have been low revign motors.

Anyway, what is a good range to stay in? I don't want to lug my engine but I also don't want to over rev it [img]/ubbthreads/images/graemlins/smile.gif[/img]

Thank you all for the help,
Luke

cdnsarguy · 11-26-2005, 11:19 PM

Need the rear axle code from the door label........35,39,C5,C9

BullHauler · 11-26-2005, 11:53 PM

Unless your pump has been monkeyed with, it won't allow the engine to over-rev.

They reach a certain point and that is all they will do.

Lugging never seemed to hurt these old engines, but I would probably run from 1700 to 3200 and go from there.

BCbinders · 11-27-2005, 12:53 AM

The axle code is C9, the trans code is K as well [img]/ubbthreads/images/graemlins/smile.gif[/img]

Thank you

BCbinders · 11-27-2005, 01:00 AM

If I read correctly, C9 is a 3.55 limited slip axle. and trans code K is a auto tranny? My truck has a 4 speed manual. Hmmm, maybe that means it was swapped in. I think I am going to need a clutch soon so maybe it doesn't have a dual mass flywall.

jdkline · 11-27-2005, 01:16 AM

Should have the SMF if it is a 4-speed. The crappy dual mass came with the ZF-5 which is a great tranny but the stock wheel will sooner or later need replacing. Your peak power band is around 1700-2500, above that you don't gain much. If the governor is working properly and teh pump is truly stock you should not be able to hurt the motor by standing on it. these governors are sort of soft they will allow ith to rev anywhere from 3300-3800RPM, which should still not leave you floating valves under normal circumstances. But I hate to redline it for very long. You also face a seevr fuel mileage penalty for every RPM over 2500 which is why your 3.55s are nice!

BCbinders · 11-27-2005, 06:20 AM

If I have the 4 speed tranny, what ratio is 4th gear? Is it 1:1? If so then at around 2500 RPM I would be doing a little over 100 KM/hr [img]/ubbthreads/images/graemlins/smile.gif[/img] That would be nice [img]/ubbthreads/images/graemlins/smile.gif[/img]

Joe Mc · 11-27-2005, 12:13 PM

4th is 1:1.

Monte1 · 11-28-2005, 10:46 AM

If you are into "projects", you might consider an overdrive unit to get the rpms down a bit (multiply your rpms by .8 to find the rpms in overdrive). Gear Vendors is light duty, smooth in operation. US Gear is heavy duty, a bit clunky in engagement (I still haven't figured out how to make it smooth).