MP-8 setting 30% or 15%

[sevenmacs]

Have MP-8 on my 06 Fleetwood Excursion 39S w/Cat c-7, 5050XL, have been running it at 15% since everyone here recommended that setting. Spoke with Throughbred Deisel and they recommended running it all the way up 30%. I've run it at 30% for a tank and liked the performance. Was wondering if anyone is running it at 30%, don't have a guage to measure temp. which seems to be the big concern.

[timdriver]

I run mine at 30% with no problems. The exhaust I'm running is an Aero 5050 XL. For me I don't buy into worrying about the exhaust temp. If you're climbing a long grade,gear down and back of the throttle. I've been driving BIG trucks for over 35 years, some hot rod big cam Cummins engines , Caterpillar's with big power and Detroit 8V92T's and even a V12 Detroit and have yet to blow a motor up. Just remember its gotta breath to run.

[sevenmacs]

Thanks for info, I usually don't push it that hard up hill anyway, I didn't think it was an issue, as I've heard that it runs a little cooler with the Aero 5050XL, thinking of adding the AFE air filter to help with air in, next trip I'll keep it at 30%,

[rver98]

If you talk to Brazels RV (WA) they recommend to keep the MP-8 at 15% or halfway on the rotary dial. The C7 can handle the extra HP, but the Allison may not be able to handle the extra torque over time.

[timdriver]

When I had my trans serviced at our local Allison dealer last October I inquired about the very same thing. The Allison tech and owner of the shop told me that it would take a whole lot more HP to tear that tranny apart than any C7 would or could ever produce

[OLYLEN]

Power = heat The motor was designed for the power output we had(I run the MP-8 also) now we have upped the power by 15% and all is well. Going to 30% is a maybe without a piro to tell the story. Comparing these motors to BIG over the road motors is like comparing your honda to a NASCAR and trying to run the same. But I'll stay with the 15% and be happy. JMO

LEN

[sevenmacs]

I think the tranny can handle the extra torque, since they put this tranny on higher HP motors as well. Many of these motors are detuned for the road and capable of higher torque & torque, thats why some motors will be reprogrammed by Cat dealers to put out more torques& HP.

Throughbred Deisel says that the best performance can be obtained at 30% without any risks to motor or tranny. Was looking for someone running at 30% with a guage to tell temps, just curious

[stuhly]

I have the 5050 and the MP 8. I have run mine at 15 and 30. 15 gives me all the power I need for 40 foot pulling a 4x4 Tahoe. Just keep an eye on the Temp.

[MaverickBBD]

I think the OP was seeking data. I would also be interested in seeing NUMBERS and any delta between the two settings.

[ninos]

i got the air filter the 5050xL and the mp8 and i ran my rv at the dyno at a cat dealer and the 30% setting defenetly makes a diference and the numbers were higher but I will go in my rv tomorrow and look at the print out sheet from the dyno and I will post exact numbers, and for the record more power doesn't mean more heat like some people like to say because my rv stayed on the dyno for about ten minutes each run in the month of july so it was hot and the engine temperature never went over 192 or 194 but i will give you guys the numbers tomorrow. Joe

[OLYLEN]

The more power you put out the more diesel you burn and the more heat you make, just because your radiator can keep the coolant at a temp does not mean the pistons are not burning though. Only a piro will tell the tale or a burnt piston. Mine was on the dyno too and kept at normal operating range. My gain at the rear wheels was 40 HP and 100# torque at the 15% setting and at this setting was right in the 15% hp and the 16 % torque at the rear wheels. Running the AFE aircleaner and the MP-8, will see on the 5050xl or straight pipe.

LEN

[jauguston]

Appearently you guys that talk about 15% or 30% settings have had your MP-8's for quite a while. They no longer use that system and mine is over a year old and has the new control system.

Here is the story as told to me by the fellow at TS Performance that developed the MP-8.

When they put it on the market with the 0%-15%-30% switch for controlling it they began to get customer feedback that they were sometimes getting warning alarms when using the 30% setting. They were few and far between but they investigated and found the Cat Engine computers had a fairly wide range of accuracy and some computers reacted differently than others on the same model engine. To deal with that issue they went to a rotary reostat type control like the volume control on your radio. That made the control inputs to the MP-8 linear instead of three steps. Problem solved.

The recommended procedure is to get in a hard pull and start turning the control up. At some point the alarm will activate. Turn the control down just until you no longer get the alarm. Leave it there. I find on mine I can run mine with the dot on the knob at 6:00 with 12:00 being off on most but the steepest longest hills. I turn it down to 5:00 and over the hill I go. The MP-8 will LOWER EGT when turned up. On mine about 50 degrees. I have a Isspro pyrometer with the sensor in the exhaust manifold right at the flange where the turbo bolts on.

The newer rotary controller is interchangable with the older 3 position switch so you can upgrade if you want to.

Jim

[sevenmacs]

I have the dial as well, I assumed that half way was 15% ( 6 o'clock) and all the way 30% ( 12 o'clock ) your saying that full setting runs cooler ?

[jauguston]

There is really no 15% 30% any more. Yes EGT is lower with it turned up. You may or may not be able to run on the 30% setting. Some can and some can't. That is the reason for the rotary dial. Run it as high as you can without getting a alarm.