HPJunkie

I have a friend that runs a procharged 502mpi and weve been talking about raising the rev limiter. I am thinking 5800-6000. The thought is to rev it higher with a smaller pitch prop and reduce stress on the drive and inprove holeshot as well as acceleration.

Griff

If its a stock cam, it will rapidly start losing torque beyond about 5200rpms.

articfriends

If your asking if the mefi3 ecu can be raised that high the answer is yes,mine is,Smitty

TylerCrockett

I can set your Rev Limit up to 6000 Rpm on the Mefi 3. The newer Mefi 4's can go to 9000 RPM. Tyler 8103242720.

HPJunkie

Thanks Tyler,
I do have another question though. If I set the fuel pressure up to give the proper o2 reading on top end then the idle mixture will be rich? Ive heard of a resistor that "fools" the temp sensor to think the motor is warmer than say 120 degrees therefore keeps the motor out of cold start mixture. ( all of this because of the no thermostat procharger setup) can this be fixed with your programming?
Greg

Elite Marine

Yes you can change the value in the ECU. Or change the pulse width on the injectors at the idle RPM and MAP.

Tyler is the man when it comes to setting them up properly!!

Mark at Precision is good too, but Tyler can do it in your boat and he's in MI

HPJunkie

How can I tell if I have a mefi 3 or 4?

Noise Pollution

There's two MEFI 3 ECU"S. Ser. no end with 099 or 999.
Not too many 999's. Either will work. Just different programing.

TylerCrockett

I can program the ecu so you will not need the box. I will never be right adding all the extra boxes.

articfriends

Tyler,I wanted to raise my rev limiter when I dyno my motor with you again in a few months,you already have it set to 6000,can we eliminate it completely and just use my msd pills or will I need to convert to a mefi-4 to go to 6400? Smitty