Can too low an RPM on a Series 60 hurt MPG?

[belfert]

I talked to the local Detroit dealer, Interstate Power, about any HP upgrades to my engine.  They said that my engine with the DDEC III could be upgraded to 365 HP, or it could be upgraded to 350/400 HP.  400 HP @ 1800 RPM and 350 HP @ 2100 RPM.  He said it was a software upgrade only and no new turbo or anything else required.  Cost would be about $700 for the upgrade.  He also said I have a TV45 turbo if it has not been changed.

I also asked about any possible missing updates that should have been done to my engine.  He looked it up and the only warranty work was a new alternator at 35,000 miles.  There are no updates or recalls ever done on my engine and nothing that should have been done per the computer.

I'm not sure I really want to make any changes right now.  If I did do it I don't know if I should do the 365 HP, or the 350/400 HP.

[B_K]

I would bet the biggest reason previous owners didn't do it is because it is hard to do.  The local Allison dealer was going to charge me something like $750 to do it, plus they needed a letter from an engineer at the original manufacturer stating it is okay to make the change.  Jack Campbell knows an Allison dealer in Florida who will reprogram WTECs for $100.  The catch is they need the CIN number from another WTEC that is programmed the way I wanted it.  They wouldn't just change parameters in my WTEC.  Jack provided the CIN number from his MCI with Series 60 and B500 that has 6th gear enabled.

I figured I couldn't really hurt anything by making the change.  I certainly never expected I would get worse mileage.  I figured at worse I would get the same MPG as always.  I figure it cost me around $300 for the programming change, shipping, and extra fuel used.

Brian if it was only $750 to do it, and it was supposed to improve fuel economy. MANY of the original owners would have done it in a NEW YORK minute and found a way to get'r done!

But believe it or not with the HP and gearing they came out with someone must have known what they were doing when they locked out 6th gear for the reason of it not having the torque to keep it rolling in the prime zone @ average speeds.

Now on the other hand once the HP/Torque is upped and an improved MPG could be seen that would be another story.

If it were me I'd do the 350/400 the first time because more than likely once you go the 365 you'll ultimately decide that you want the other 35 hp and have to pay more to have it done a second time.

Personally I like the dual power setting and it encourages the use of cruise control where the bigger HP is  and thus even more advantage.

Just my way of thinking and let us know how it turns out for ya.
  BK 

[belfert]

Brian if it was only $750 to do it, and it was supposed to improve fuel economy. MANY of the original owners would have done it in a NEW YORK minute and found a way to get'r done!

I bet the only way they could deal with the letter from an engineer would be to forge such a letter.  It simply wasn't worth $750 to me to make the change and I didn't really want to forge a letter either.  For $130 or so, I decided to gamble on doing the change and obviously I lost.

If it were me I'd do the 350/400 the first time because more than likely once you go the 365 you'll ultimately decide that you want the other 35 hp and have to pay more to have it done a second time.

Personally I like the dual power setting and it encourages the use of cruise control where the bigger HP is  and thus even more advantage.

I really don't know that I am going to spend the money to up the horsepower although if I got .5 MPG better it would pay for itself in three to four years.  We always use cruise other than serious mountain grades where cruise isn't a good idea.  We'll just have to remember to downshift to 5th gear when starting out.

I did find a guy who customizes DDECs and can put in a 485 HP program that he says won't hurt the engine as long as one installs a pyrometer and watches the temp.  This sounds nice, but a toasted engine the one time someone forgets to watch the exhaust temp would get expensive in a hurry.

[B_K]

Have you tried the "mode" button since changing the TCM?
All of our buses (except "Dino") go to a 5 spd mode when we use it.

Worth a try.

And no I wasn't thinking of a forged letter. Groups of people like multiple bus company owners (especially with multiple coaches) can usually get better results than the average "Joe Blow off the street who only has one bus converted into a camper."

And maybe not. I'm just saying that I can guarantee you if there was proof that it would benefit them with better MPGs the original owners would have found a way to get it done! (even if it meant doing like you did and swapping TCM's from another brand)
  BK