60 series engine calibration

You will have to save a lot of fuel to pay for all of that, don’t forget downtime costs

 

I'm not saying your instructor or the results are flawed, but I've had the same experience with e models and N14's, but not 60's.

In the 90's we had drivers from all over the country come to out little Freightliner dealership for overheads/fuel pressure adjustment.

Back then, there were a lot more places doing dyno's, and I had several done. You figure an engine should put 80% of rated HP to the wheels, so 400 for a 500 rated engine.

A customer brought in a truck running rough. 98 model 500. Cam seal had been replaced. I checked timing, which was one tooth out. Ran the overhead and adjusted fuel pressure. Had CAT dyno the next day, 506 to the wheels.

 

What size tire are you running?

This engine is not meant to work under 1400 rpm.
1300-1350 is well under a series60 operating range.
1250-1275 is abuse. Period.

Run in 12 gear, not 13.
2.90 rear: 11r 22.5 tire: 1400 rpm : .86(12 gear): yields 68.5 mph

Change your tire size to dial in your desired speed. Its a fraction of the cost of changing rear ends. And for God's sake get your motor up to 1400-1500 rpm. I know some guys run their 60 series at not less than 1600..... some even at 1800 with good success.

Unless you're empty ever where you go I go don't see how you pull at 1300, never mind 1250.

Your using your motor wrong sir!!!!!

 

I can't stress this enough...... The solution is free.: use .86 gear.

Do you have a load gauge in your truck?
If not I highly recommend one. I guarantee at 1250-1350 rpms you are loading that motor to 85 to 100% most of the time( if you are loaded, and not going downhill. )That's lugging.

I never run over 75% engine -load. I just keep dropping gears to let it spin. This motor just loves to spin free and easy, and will fall on it's face under 1400 ( 85% engine-load or more). If you have a boost gauge this will prove it to you.

The money savings you're looking for will come in the form of engine longevity.
I currently have over 1.1m on mine and it's never been opened up, and uses zero oil between changes.....

I aim for keeping my % engine load under 50 except for climbing and let it live a stress free life by staying out of .73 gear.(3.55 ) Of course being a live stock hauler in Northern New England I spend a lot of time digging around in the gear box.....but , what else do I have to do while I'm just setting there looking out the window.... Not lugging it has paid me dividends, I think it can you as well, IMHO.

As far as super singles, if you're your own hired hand , no reason you have to stay married to them. Go back to duals and open up a lot of RPM options . lots cheaper than swapping diffs.

Anyhow, best wishes mister.

 

Will the MPG suffer? Also, what would you suggest as the optimal operating range for a 14L with 515 HP and 3.55 rears?