Fuel Management Unit...

[Cyrk]

I sprung a nasty leak from my SC on Fri... leaking from the seals/rings on the unit. I found a great new speed shop locally and he was willing to squeeze me in to reseal the SC.

While he was under there we added a 10:1 FMU. I cannot remember the name of who makes the unit. I think it was HKS or Vortech, I will ask him on Monday.

I feel like the VX goes into boost much smoother and has a tad more power when in boost. I also have noticed that my weird idle for a sec at startup in the mornings has vanished. Seems to feel over all smother. I am going to go get it dyno'd again soon to see if the curve when I am in boost has smoothed out and if it is running richer now as I was running a bit lean.

Over all I am very happy... so far with this mod, then again I have only got to drive it for a day.

Some photos of the unit, pardon my dirty azz engine, it is getting cleaned soon.



In a nutshell, the FMU adjusts fuel pressure when the boost comes on, regulating it at normal levels during normal operation and dramatically increasing it on demand. It is purely a mechanical device, using different sized disks inside the unit to alter the pressure at which the FMU takes effect. This makes it relatively easy to install and adjust.

FMU allows the car to run normally on a small injector, but can also increase the rail pressure under boost which, in turn, forces more fuel through the same size orifice. The fuel that the FMU adds has a direct relationship to the boost pressure.

The Pressure ratio determines how much the fuel pressure is increased per psi of boost pressure. A 12:1 FMU, for example, will increase fuel pressure by 12 psi per psi of boost. It is typically recommended that a 10:1 or 12:1 FMU be used in order to ensure that the A/F mix will not be lean.

[volume311]

Noice..just make a bracket for it now, can't have something like that bouncin around with zipties.

[Ldub]

MMMM...Alien technology...flying saucer :homer:
In all seriousness, Looking forward to seeing the numbers/curve.Also, was the part itself (w/o labor) co$tly?,instalation, plug & play or complex?
Also,also, what were the symptoms w/ leaking s/c?
TIA, Ldub

[MZ-N10]

wouldnt adding addition pressure to the fuel rail increase teh stress on the fuel line?
or is it so little its it doesnt matter?

i remmeber that when i on the rx7 forums they were talkin about a fuel pressure regulator. they modified it to increase fuel line pressure. is this basically wat ur talkin about?

[Tone]

Our FPR is already adjustable and since the injectors don't stay open any longer, there is minimal advantage to increasing the pressure, even momentarily. If you adjusted the stock FPR to a higher pressure, the stock ECU keeps the injectors open the same length of time at low speeds and increases it high speed/load which is very similar to what you are doing, that is why there is a pressure connection on our regulator. More boost causes higher pressure. I look forward to the Dyno scans.

[MachineVX]

I'm interested in the numbers, too. The Greddy E-Manage might do what we need in order to run more boost.