MP-8 alternative?

[jauguston]

Some of the power increases (not all) that the MP-8 provides has nothing to do with increasing fuel flow. It alters the timing of the fuel injection event. The engine manufacturer (CAT) was forced to change the timing event to reduce emissions forced by the government. The MP-8 returned the timing back to where the engine designers intended it to be. This increases the power but the engine will not pass emissions testing if it is turned up. Turned all the way down it will test stock.

[deSanford]

I called MP-8 and I was told to turn the rotary knob all the way up and leave it there. The ECM will decide what it needs to do to handle the load. I have a Cummins ISB 340HP 6.7L model that doesn't use "cow" piss aka urea. Anyone else have this engine and what is your thoughts? deSanford

[Family Time]

Originally Posted by jauguston

Some of the power increases (not all) that the MP-8 provides has nothing to do with increasing fuel flow. It alters the timing of the fuel injection event. The engine manufacturer (CAT) was forced to change the timing event to reduce emissions forced by the government. The MP-8 returned the timing back to where the engine designers intended it to be. This increases the power but the engine will not pass emissions testing if it is turned up. Turned all the way down it will test stock.

While I believe your first statement to be true, the second not so much. The MP-8 doesn't actually change the timing, but reports a lower than actual boost pressure signal to the ecm and in turn calculates a fuel event in lower than actual load cell and thus a possible timing increase.You are still dealing with a low nox timing map so any increase will be no where close to optimum. If the timing was optimum I believe you would be seeing true corrected fuel mileage increases to the 9-11 mpg as some preemission motors get.

[jauguston]

The explanation of what the MP-8 does I posted was the explanation given to me by Randy at TS Performance when I was researching it prior to my purchase of one. It may be a generality of specifics but it made sense to me at the time and still does.

[rssnape]

Great



1997 Tiffen Allegro Bus 37', Cat 3126

[1ciderdog]

Originally Posted by deSanford

I called MP-8 and I was told to turn the rotary knob all the way up and leave it there. The ECM will decide what it needs to do to handle the load. I have a Cummins ISB 340HP 6.7L model that doesn't use "cow" piss aka urea. Anyone else have this engine and what is your thoughts? deSanford

Interesting. I have an MP8 and if I turn it all the way up it scares the devil out of me - that's at the top of a summit when I let off the fuel and it shifts down. The stop engine & check engine lights and buzzers come on. I've basically turned it off or actually way down. Mine is a CAT so perhaps different on your engine.

[deSanford]

Understand 1ciderdog I also leave my MP-8 OFF. With my fuel lift pump I have all the power and cool operating engine I need to climb hills etc. deSanford

[wb7auk]

Originally Posted by rssnape

Great



1997 Tiffen Allegro Bus 37', Cat 3126

As a point of interest:

The MP-8 on a 3126B engine does not increase the boost as it does on
the E and C-7 engines.
It takes a mod to achieve the extra boost.
The C-7 does not like boost over 27 to 28 lbs without a change in the ECM program or a mod to the waste gate.
The 3126B engine stock has some where between 24 and 26 lbs of boost
at the turbo and with the mod the boost can be increased to 30 to 32 lbs
at the intake manifold which is a hp increase of about 87 hp with the MP-8.

[mel s]

Originally Posted by deSanford

Thank you Family Time I had no idea what a "HEUI" was. I also learned that the oil pressure is what controls the time duration of the injectors (is that right?). doorguy do you have a rotating knob or a fixed position switch for your MP-8? I have a boost gauge and a pyro gauge. Do you leave it on 15% all the time or just when climbing grades? deSanford

As I understand it...the HEUI pump provides the high pressere oil to operate the injectors....the ECM controls the operation of, (and the time duration of), the injectors.
Mel
'96 Safari.. 3126 Cat

[wb7auk]

Originally Posted by mel s

As I understand it...the HEUI pump provides the high pressere oil to operate the injectors....the ECM controls the operation of, (and the time duration of), the injectors.
Mel
'96 Safari.. 3126 Cat

Correct

[deSanford]

OK thank you for the clarification Mel s, and Wb7auk. So with my high pressure fuel line "shimmed" my Foss High Pressure Lift Pump is able to provide diesel fuel at HIGH pressure for the injectors to mist the fuel into the combustion chamber which helps provide good power and maybe extra mileage. The way my engine performs now with the MP-8 OFF I don't have to monitor my pyro and boost gauge so closely going up steep grades in lower gears with substantial RPM. This is assuming the engine fuel pump is not restricting the pressure from the Foss. There is a lot I don't know, but I do know from experience that my set up now does all I need at this time. deSanford

[jauguston]

If you make modifications to the wastegate operation to raise the boost pressure above 28 psi on a C-7 the ECM will sense that and defuel the engine reducing power. It is plain to see it happening if you have a pyrometer as well as a boost gauge. When the boost goes over 28 psi the EGT will drop indicating refueling by the ECM.

Jim

[wb7auk]

Originally Posted by jauguston

If you make modifications to the wastegate operation to raise the boost pressure above 28 psi on a C-7 the ECM will sense that and defuel the engine reducing power. It is plain to see it happening if you have a pyrometer as well as a boost gauge. When the boost goes over 28 psi the EGT will drop indicating refueling by the ECM.

Jim

Jim,

That is true without the MP-8 but with it the boost reported to the ECM
is much less than the real boost seen at the intake manifold.
If the boost being sent to the ECM is the same real boost you have a
problem with the MP-8. That was the problem with the first MP-8 I had
and they corrected after a few phone calls to Randy.

[jauguston]

Art,

I have a MP-8 turned up all the way all the time. When my boost reaches 28 psi the EGT drops.

What does yours do different. What did Randy say it should do it was not doing. I have had mine since early 2011. Have they upgraded them since then?

Jim