Fuel management unit

[pr0]

Do I need a FMU to turbocharge the RS? Can't I just use an S-AFC?

 

[green95hrcgs]

From what I have heard, using an S-AFC alone is not good for our cars. Get something like the Vortech S-FMU rising rate fuel pressure regulator. That along with larger injectors will be a decent starting point until you want to go to something else like an 8-injector setup like a lot of people at 2gnt.com are running.

The S-AFC when used to tune, can alter our MAP sensor voltage to a point where our ECU starts to advance timing too much. On a turbocharged car, that is bad news. The S-AFC CAN be used on our cars, but only for VERY FINE tuning after you tune with the S-FMU or other product.

The Vortech FMU is not as adjustable as the S-FMU.

 

[pr0]

Thanks for the info green95hrcgs, I will look into the S-FMU, but anyway, what are you using?

 

[green95hrcgs]

I am currently using 415cc injectors, the S-FMU, and the S-AFC to fine tune. My car is still not tuned by any means tho.

I am probably going to be getting rid of the S-FMU because I am switching over to the 8-injector setup hopefully before the DSM Shootout in August.

 

[baxsom]

can the fmu from a hahn turbo kit be used to run bigger than stock 420A injectors
say about a 550cc

 

[green95hrcgs]

The HRC kit does not come with an FMU. The FMU and the S-FMU are from Vortech. HRC uses a Cartech FPR ( fuel pressure regulator ). All of them are fuel pressure regulators, but to avoid any confusion, follow what I just stated.

The Cartech FPR that comes with the HRC kit is known to be unreliable. It does not provide rock solid performance like the 2 Vortech units do. The S-fmu is the one that you would want to get because it is WAY more adjustable than even the FMU. The Cartech is better known as the CRAPtech. Get rid of it, especially if you want to get bigger injectors.

The S-FMU is not cheap ( $289.00 ) from Summit Racing, but its well worth it over the other two units.

 

[baxsom]

that clears a lot of confusion
thanks

 

[Raph]

does this apply only to the 420a? or to the 4g63 nt too?

 

[RAVAGER576]

I second green's post ...

I have the cartech and its the biggest pain in the a** ... inconsistent base pressure and no peak pressure adjustment ... the "bleeder" seems to do nothing IMO and Im running super rich now that I swapped to 310cc injectors. I can still run and I still get decent boost but timing is so jacked I can hardly feel the neck snap effect when spooling. Need the vortech SFMU soon! Right now I can get spanked by light modded 4g63s and Im not happy!

Grab the Vortech!

 

[green95hrcgs]

does this apply only to the 420a? or to the 4g63 nt too?

I am not sure about the 4G63 N/T.. I am only speaking from my experience with the 420A.

 

[Raph]

this looks like it can help with tuning the us spec 2g nt..

http://userwww.sfsu.edu/~ecg/smcfaq.htm#five