Right now before my rebuild I have been running with my SFMU and the 3.62 disc with about 50 psi of idle fuel press.

Now I am getting the 440 injectors and a SAFC.
What setting or disc would I use on the SFMU or should I just leave it as I have it???

Go here - www.geocities.com/vttalon/tech.html - just about everything you need to know.



Eric Madden

Check those pages out again...I'm sure you've seen them before. I think what you'll find is that you want a lower ratio disk and run a lower idle pressure. For comparisons sake, I ran my 440's, SFMU, and SAFC with the following settings:

idle pressure at 26 psi with about -20% on the S-AFC
1.5/2:1 disk. I don't remember what my S-AFC settings were at full boost. A datalogger is invaluable for tuning new fuel setups.


Corbin

'95 ESI-T
HRC+FMIC+ETC...

Does the 1.5/2:1 disk and the ring come with the S-FMU kits? Coz I just got the S-FMU form Vortech and they came with an extra black spring ,3 different sets of rings and disk, which the calibration washer dia. are 2.72, 2.47,and 2.22. Right now I am useing the 2.47 disk with the medium size of ring and standard spring. I am planing to run at 15 psi max after tuning. So should I change the spring to the black one and order the 1.5/2:1 disk? I have my motor rebulid with 8.5:1 piston, S-AFC, 440's injectors, HRC stage 2 with FMIC kits. Any suggestion will help. Thx

Eric

after a little bit search, I found the answers for myself...:P
The Fuel pressure issues discussed before are almost SFMU + stock injectors. Here is the new question, now I got S-AFC, the SFMU with lower ratio disk,like 3.2:1,even if I got 440's, the idle pressure
and boost pressure are still the same as I got the stock injectors'? like I need 50 psi when idle, 60 psi when 0 boost and 110 psi when 9psi ???? Is that correct??? but how about if I want to boost at 15 psi ? The fuel pressure will be the way too high?

Eric

You may start your quest by following the steps in:
http://www.houstonhardware.com/~cbehnken/example.html
Choose a 440cc/min injector instead of 370cc/min. Then calculate the proper fuel pressures and disk sizes needed for that injector. That will only get you answers up to 275 hp (9 psi on stock internals). Getting from that point up to 15 psi on 8.5:1 pistons is up to you. All I can do is provide equations. I have no experience with big boost and rebuilt engines.


Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire