Non intercooled Eaton M62 on an M20B25, stock otherwise fuel system (aside from high psi fuel lines)

I used a 10:1 but some use a 12:1


I think what vortech actually recomends is,

14 lb injectors = 12:1
19 lb injectors = 10:1
24 lb injectors = 8:1
30 lb injectors = 6:1

what does "FMU" stand for?

"Fuel Management Unit"

Thanks for the help, which is my stock injector size?

"Fuel Management Unit"

Thanks for the help, which is my stock injector size?

thanks. i guess that is what i have always referred to as a piggyback.

Piggyback is things like an AFC, Emanage, whatever else is out there. They're computer controlled fuel modifiers that alter your air flow meter's signal to the ECU so it dumps more or less fuel.

FMUs work by raising the fuel pressure per pound of boost.

12:1 would be 12psi fuel pressure for 1psi of boost. They're a mechanical unit in the return line that further backs up fuel beyond what the stock FPR does.

what does "FMU" stand for?
F*ck your Motor Up :stickoutt

These are band-aids at best that jack the rail pressur up with respect to boost pressure. This in turn, increases the flow rate through the injectors by a non-linear amount, starting from an arbitrary point. Sure, they can give okay results, but as conditions change, so can your delivered A/F ratio. Remember fuel flow must remain proportional to airflow, NOT just pressure. The ECU doesn't have any clue what you've done to fuel delivery when an FMU is used. The proper solution is to just run the right size injector and ECU tuning in the first place if you want great results under any conditions..

But if you want something cheap and easy, FMU is the way to go. :P

I found an adjustable one i'll be buying and i'll invest in a wideband to get it to the area of where i need it.

If you are going to run an FMU.......I dont suggest it. But if you are, there is only ONE to buy.

Vortech SFMU. Its the only one with bleeder valves on both sides of the diaphragm to allow you to actaully curve your fuel delivery pressure.

Theyre available on Ebay VERY cheap and are also very reliable. They're the only choice when using a rising rate FPR for fuel enrichment.

I spoke my peace.


They actually do a VERY good job for what they are and do. Ive seen dozens of turbo mustang's and F-bodys as well as 500+ DSMs years ago with dyno graphs that look as smooth as standalone.

One thing you loose, is the longevity of your injectors. Theyre not meant for the massive pressure theyll be holding back and DO fail.


"Good luck my son"

Thanks, but i actually already ordered a BEGI which can bleed boost and has an adjustable spring (like a GReddy BOV).

I've had headaches with ECU tuning, i just want a simple set-up. No oil line headaches, no electronic tuning.