i have a friend with 30lb injectors and a FMU right now. he will be upgrading to the SFMU so we can tune his idle FP down, right now he has to lean out so much with the SAFC that its causing timing issues. i dont have much experience with SFMU's, and he is wanting to run 12psi with his 30lb injectors and SFMU. with that in mine, what would you suggest him setting his idle FP at(i know you set it with the vaccum line unplugged, the plug it in and it drops), and also, would he just use the 6:1 disk it comes with, or switch to the 2.72" disk and dark spring for 12psi? thanks for any help guys. he wants to use the SAFC as little as possible.




www.TeamKLR.com
1997 Silver RS
12.3@118mph,20psi, race gas(drag radials)
Wiseco 10.5 Pistons
Eagle Rods
Started as a manufactured turbo kit, now its a custom one!
Greddy Exhaust
440cc Injectors

Waiting on the EVOlution!

My setup is a little different from your friend's because I'm running 415cc injectors (40lb I think?). When I had the cartech FPR on my car, my SAFC curve started at -25% at idle and went to about -17% by 6000rpms for the low throttle point.

Now that I have the SFMU installed with my idle fuel pressure at 30psi, my SAFC curve starts at -7% at idle and goes to zero at 6000rpms.

well not knowing his exact setup (turbo, auto or stick, ect..), here are my numbers.

At idle, i run about 25 psi of fuel at 17 hg's of vacum. This idle fuel pressure gave me very good fuel trims acording to the datalogger. I was running about 30 psi and got a too rich CEL constantly because fuel trims were maxed out at -25%. The car idles and runs great at 25 psi fuel. I currently run the 2.72" disk, and use the optional bleed valve for precise boosted fuel pressure adjustment. Right now, i am running a good 8 psi and in 4th gear on the highway on a WOT full boost run, i get and will reach 1600 degrees on the EGT gauge. Since the cold ass wheather here in Michigan, i have been running a just a tad bit lean. I'd like to see EGT's around 1500 in 4th gear. I also use the short, dark spring inside the SFMU, as this one does NOT come with it. This spring will let you idle with a higher fuel pressure, and a slightly higher boosted rise rate over the factory installed long silver spring. 0 psi fuel pressure (static) is around 33-34 psi, and fuel pressure at 8 psi boost is around 66-68 psi. Almost perfect if it wasnt so cold.

If he wants to run 12 psi, and i will assume its a S16G turbo setup:

30 lb injects
SFMU with dark, short spring
-3.64" or the largest disk (i believe thats the size)
-get the bleed valve option and put that on the SFMU to drop the boosted fuel pressure a bit with that disk. Dont forget to use a vacume check valve on the bleed valve so as not to draw in any air under vacume conditons. I just used the HRC one that came with my Cartach FPR. If you dont use this, it can alter your fuel pressures a bit.
- start out idle fuel at 30 psi, WITH vacume line connected. You dont need to disconnect it for any reason, so just do all tuning and adjustments with it on. Your fuel pressure will rise from full vacume to static about 10 psi. That is fine.
- start with the bleed valve all the way closed, so its not bleeding off boosted fuel pressure. You *should* be damn rich like that at 12 psi. Tune down and lean out from there by turning out the bleed valve at 1/4 turns at a time until you get about 1500 degrees on the EGT in 4th at WOT at 12 psi. Shoot for o2 voltages at WOT NO LESS than .95 in 4th gear. You want to run VERY rich at 12+ psi to avoid detonation
- I dont like the SAFC, so i say dont even use it. I dont and my car runs great, and fuel trims are excellent. Once you go over 30lb injectors, the ecu will have a hard time tring to run stock like fuel trims, even with low idle fuel pressure. I have heard that even idleing at 25 psi isnt good, but hell, the car runs great at idle with that fuel pressure.

You MUST datalog the car to tune this setup. Your actual numbers you may need can be off from my setup. By watching your long and short term fuel trims, you can adjust your idle fuel pressure using the top adjustment bolt on the SFMU. Adjust the fuel pressure down low enough so that you are within -10 to 0 LTFT. Thats 25 psi of fuel at idle for my car. Then drive around keeping the car in CLOSED LOOP while boosting light and then monitor fuel trims. Shoot for the same numbers as above. It may run a bit rich and STFT may get into the higher negatives (-20 or so) with this fuel setup, running the largest disk, but you may be able to smoothe out the full vac to static fuel pressure by using the vacume adjustment screw on the SFMU.

ok i'm done :)

Thanks man. he has a star stage 2 kit, so its the T3/T4 turbo. about that 3.xx" disk, does the SFMU come with that? and the short, dark colored spring, i was told camr with the SFMU, but it doesnt? im guessing you have to get all these through Vortech correct? and the bleed valve from HRC? thanks for your time man. you know your fuel my man.. :-)



www.TeamKLR.com
1997 Silver RS
12.3@118mph,20psi, race gas(drag radials)
Wiseco 10.5 Pistons
Eagle Rods
Started as a manufactured turbo kit, now its a custom one!
Vortech FMU
Greddy Exhaust
440cc Injectors

Waiting on the EVOlution!

>Thanks man. he has a star stage 2 kit, so its the T3/T4
>turbo. about that 3.xx" disk, does the SFMU come with that?

I'm not sure really...i bought mine used and it was all fucked up so i had to send it to Vortech for rebuiling..there is a kit available through them that has all the disk/rings and springs in it. I do believe the SFMU does come with the 3.64" disk, and long silver spring if i remember now...

>and the short, dark colored spring, i was told camr with the
>SFMU, but it doesnt? im guessing you have to get all these
>through Vortech correct?

and the bleed valve from HRC?

Well you have to get the disks springs through Vortech as far as i know. YOu can get the bleed valve and vac check valve through HRC. The bleed valve that they use on the Cartach FPR is the SAME exact one that the SFMU uses, and i think its a bit cheaper through HRC...
>

i got my vortex super-fmu new from vortex. it came with the 3.** disk pre-installed, and has the next two disk and rings in the box if i needed them. also the long silver spring was pre-installed, and the dark short spring was in the box. i heard of some people getting the dark short spring and some not. but as far as i know its comes with the super -fmu when you buy it new. i got the bleed valve from vortex since i did not know at the time its the same as the hrc one, so i think jamesman is using mine now? im unsure, but yah you can use the hrc bleed valve thing.
good luck


Michael 99gs
HRC Stage 2
Stage 3 process begins gathering parts for rebuild

http://www.dreamwater.net/purplebeast