We purchased our first coach a few months ago, a '95 U320. Since then we have made a couple of trips in it and by no means does the bus lack in power but I would like to get some more grunt out of the M11 for pulling my horse trailer and Jeep. I have done the resonator and complete 5" exhaust, which sounds great but didn't add any noticeable power. We went through the engine thoroughly upon purchase, checking fuel pressures, diagnostics etc. , everything checks out fine. With that being said, I have done some research and talked to several companies that can reprogram the CPU with claims of adding 100RWHP and 250+/- Lb Ft of torque. These numbers sound great and well within the ratings of the transmission and torque converter, we have done this to many of our other cummins engines with great luck...
Has anyone else had any experiences with tuning upgrades?
Look in here for Dave M. posts on upgrading his ISM from 450 to 500. He had to put on a new turbo to get it up there, so it is more then just the ECM upgrade.
ah the itch has struck. join the rest of us. the later red top 450's had stellite valves and a block support and strong pistons.
unknown if your 400 has any or all of these. max on the red top was 450hp and 1450 torque.
no one makes an upgrade for the celect or celect plus to my three year search.
after the celect plus cummins went to the ISM which has a much higher pressure fuel system which allows multiple fuel injection squirts per firing cycle.
yours and mine are one squirt. noisier. that's why the new diesels are quieter as the fuel is injecdted 4-5 times during the firing stroke.
I have not finished a long run test but after three years of diagnosis the main issues were the fuel lines were cracked from the ultra low Sulphur fuel and all needed replacing. second was the winn fuel filter system has/had vacuum leaks continuously after multiple repairs.
lastly my m11 and yours both have the same cam position sensor. unless replaced it fires the injectors at incorrect times. the en gine compresses the fuel mechanically but when it fires the injectior is elecdtrical.
oil gets in the cam position sensor and shorts out both internal sensors. main and backup. no codes. frustrating.
replacement unit has a solid alloy end cap impervious to oil.
you can hear the erratic idle if the sensor is bad when standing at the rear with the motor idling.
or ignition on but motor not running you can hear the buzzing at times from the injector trying to fire but the motor is not turning over. that's how my shop foreman noticed it.
last part I replaced was the ambient air pressure sensor. more accurate.
neither part is expensive but three years of my time and thousands of dollars to figure out my issues.
told every shop something seemed wrong. but no codes mr owner...
if you replace the sensors and fuel lines and add a rarker/racor filter with the integrated pump and nothing changes and the rack has been run and the valves adjusted and no blowby out of the valve covers from bad rings then what you have is what you have.
then the power is part of the natural beauty of the vehicle.
Pittsburgh power back east kind of vaguely mentioned if I left it there for a few days maybe they could look into it.
my take on that was they knew for sure how to increase the power but were unwilling to publicly violate smog laws and put any such thing on paper.
they did recommend the Donaldson foam air filter for better flow in.
surely let me know if any of my long term work relates to yours and did it help.
mine I think was bad for a long time. short run silverleaf gas mileage seems to have jumped up. noticeable sharper throttle input.
hard to explain but seems stronger.
now for my muffler replacement with an aero 5050.
one step at a time for me.
bought the aero first but was not satisfied that any engine issues were totally addressed. turns out I was maybe correct.
need a 500 mile run to compare mpg.
plus the misfiring may have lessened the ring seal from wqahing down the cylinder wall. should reseat the rings a bit I hope whit a strong run and a load against the motor.
then another dyno run. mine is supposed to have 300-310 hp at the rear wheels. had 250.
if this stuff was easy little kids would do it, three cummins shops. finally my hero heard the buzzing with the ignition on but motor not running then the erratic idle as the cross check.
hope this helps.
possible to make the 400 celect into a 450 celect plus but maybe not fixing all issues first is the way I went.
love to leave it at the pittsburg guys and ask no questions.
the ism mods with the waste gate will not work on ours as they have no waste gate BTW.
yes I asked EVERY question.
check for charge air cooler leaks of course. a turbo inspection should be done also, easy to dust the turbo it seems if bad airfilter use...
I have the same engine (M11 400HP). I asked Cummins in Coburg, Oregon if it was possible to program it for more horsepower and torque. They said no.
jor
If I were asked, the 1st thing needed was different exhaust, why I gladly went to the Walker resonator, that made about 2-3 psi increase in turbo boost, then did the Cummins approved ISM conversion, which increased the boost another 3-4psi. The end result was a very noticeable increase in get up & go. If you have done the resonator and it has not made a noticeable improvement, I doubt adding another 100 ft lb and 50 hp would be noticeable either. Sure was an eye opener for my setup, I also had the girdle installed on bottom end, found later it is not really needed until after 1 million miles.
The reason for the different exhaust, the new bypass turbo would not connect up with original muffler.
Would do it again, cost about $3,400.00, but has Cummins blessing.
The 1995 M11 is not the same animal as the 2001 ISM.
I also highly doubt Cummins shop would take the time to work out all the details required to make the upgrade unless you spend a lot of $$$$$ with them routinely.
Bruce Mallinson, owner of Pittsburgh Power, is an old friend. He's been souping up N14's for both OTR and drag racing for years. I asked him your question when I bought my coach 9 years ago. He said to forget it. He said he could take a lot of my money and I might not notice the difference.
I bought my 95 U320 as a salvage vehicle. I spent a lot of time tracking down the original owner before I pursued the purchase.
During a long conversation he told me that Cummins upped the HP to 415 (approx. I have to dig up my notes for exact quote).
He was the only owner till the insurance Co.
Morphing an M11 into anything other than what you came to the dance with is a wasted exercise.
Get a later model RV. pc
The bottom end as I understand it is the same on an m11 at 450 hp as a ism. Different head? Fuel system, turbo, ecm. Easy $10k I was told.
No idea if the 400's bottom end is the same as a 450.
Sure look at the east sensor upgrades and fixes
I had to verify my coach had indeed been Foretravel factory uprated to 400 hp (all the 95 M11s were originally 376 hp, not all uprates were reported to Cummins). When we checked it at Coach Care I was asking about power increases and telling them how pleased I was with the mileage (9 plus, routinely) they said 'if you want to stay happy with your mileage, leave it alone' As a jake coach with no aquahot, its one of the lightest 320s made. If you want better performance, make like Colin Chapman and carry/tow less weight. Downsizing from the 07 Tahoe toad to the 99 Ranger dropped 2500 pounds. It feels like dancin'! Keep your water tank half full and dump often.
For several years now, have had a 1997 PETERBILT with a m 11 red top Cummins that has 1.3 million miles on it. Kept it up with only minor maintenance and regular service. I believe that engine would pull down the gates of hell. Have the same engine in our Foretravel and could not be happier with it. Why mess with perfection.
He does not have a red top in his 95. Celect. Not celect plus
I would want to have my cooling system serviced immediately before heading down to snatch on them gates! Hot as Hell at the entrance.
Have not tried the gates yet, but the standard radiator cooling system has no issue in the mountains with my 500 HP ISM setup when I push it, so if your cooling system is having issues, it might be worth a good investigation. Had to replace my radiator due to most of the fins on the inside had disappeared. Still was not an issue cooling but had not had a full test on its ability on long mountains.
While our M11 is a 1995 and not a "red top" it does appear to be very close to "perfection." It (and the rest of our drivetrain) seem to be very well mated to our coach, and we are extremely well pleased with its performance. Even if it doesn't quite make a million miles, I'm pretty confident it will outlast me!
Even though more torque and horsepower seem as if they would be nice, I definitely don't plan to "mess with perfection"!
Do check the cam position sensor. ALL the original ones fail. No backup like the ism's have.
$60 part? External to the engine.
The shop foreman at the cummins local dealer mentioned that it might be posdible IF I brought in the removed from the coach ECU to him he could install the QZM marine engine program in it.
550 hp? Plus he said he could input a torque control in the first two gears so as to not allow the extra power in non locked up torque converter gears.
Not that expensive. No warranty expressed or implied. Not recommended.
Unless of course you are able to monitor the exhaust gas temps and trans temps and engine oil and coolant temps and are able to lower the power if needed.
My old Marquis with a 3176 cat would pull all the interstate grades at 37,000 pounds combined at 8.25 mpg on cruise at 65mph up and down hills on cruise.
My shop guy wondered if gillig or beaver had turned up the cats a bit after I mentioned this to him today.
Known to happen in the Rv biz long ago.
1991. No heating issues reported to me back then but most were not driving up 6% grades loaded at 110 degrees.
Just saying.
$275 dollars plus buying a password for $75 dollars from cummins.
Just a thought. Would need to verify I have the same cooling system as Dave M and that every part in the engine compartment was in like new condition.
Probably not needed. Wanted. Yes. Like I said used to go up hills on cruise and never downshift
Barry mentions in his spec's, that the 95' M11 U320 is rated @ 450HP.
Not too sure if this is in fact correct since I find 400HP mentioned in other spec's also.
After living with my Class 8 400HP M11 for years, IMO, I'd leave well enough alone.
Aside from keeping a good tune-up and adding (whatever) fuel additive on a regular basis to improve lubricity.
Any good 2 stroke oil works very well, purchased in bulk is more reasonable than most diesel fuel additives. pc
I believe that 450 Hp value he shows for the M11 used in 1995 is in error. Everything I've been able to find related to mine is that in 1995 the M11 was rated at 370 Hp by Cummins and that Foretravel uprated it to 400 Hp.
I believe the accurate information for mine is 1350 lb-ft @ 1200 RPM and 400 Hp @ 1800 RPM.
While ya'all dreamn, remember the Cummins QSM Marine can be taken to 715 HP, that should make your scooter scoot. Cooling would be one large issue for highway operation. Fun to dream.
Dave, QSK95 @ 4200 hp will really make it scoot.
If you wanted to experiment. An idea may be to find a spare ECU and get that programmed. I'm not sure how the marine program would work though with the RPM and fuel curves. It's a much different application and use of HP. Maybe it would work fine?
There are hacks out there too. You need the inteface. Either the cummins "Inline" Cummins Engines (http://cumminsengines.com/inline) or Dearborn DG - Diagnostic "Truck" Tools (http://dgtech.com/products/diagnostic_truck_tools.html)
I made a thread a while ago about these. I haven't picked one up because I haven't needed it yet. Then one has to get the cummins, allison, cat, etc software to get in deep and change stuff. And it's possible to get that stuff, from places, but if you have to ask...etc blah blah blah.
If you look at your engine data plate, you will see a "cpl" number. This is cummins critical parts list.
You can then go on the cummins site and match up individual component numbers on the ism 450,
to the numbers for your engine. If they all match up, engines are the same, only the programming is
different.
When I retuned my engine, the independent cummins repair shop, [not corporate cummins!] did that, and said
I was good to go for an upgrade.
Jim
Jcus, so your 1999 came with the 450hp "celect+" but a software upgrade made it an ISM 500?
No, not sure of any difference with M11 or celect +, but mine was red top ism.
Ism has a multiple injection per firing stroke top end fuel system. Higher pressure
M11 celect plus is a lower pressure one injection per stroke system.
As far as I have researched.
Cylinder block on down I understand is the same.
An ism top end might be refitable to an m11 450 red top. Lots of money
If you believe wikipedia: "Later M11's received the electronic CELECT and CELECT Plus fuel systems consisting of a gear pump and solenoid controlled injectors. The M11 CELECT Plus became the ISM when Cummins applied its Interact System (hence the "IS" in ISM) to the M11 CELECT Plus in 1998 to further improve the engine. The ISM is available in four different configurations, with slightly different emphasis on maximum power (450 horsepower (336 kW; 456 PS) vs. 500 horsepower (373 kW; 507 PS)) and peak torque.[citation needed]"
It says in 1998 Celect+ became ISM. So maybe a 1999 FT has an ISM in it. Depends on what engine they got in the production line.
Yes, my '99 has the Celect+.