You never mention what kit you are running, how much boost you are running, and if you are running stock injectors. I am running 7 psi with stock injectors and I see over 100 psi of fuel presssure at WOT.
The one picture you posted is the spring and sping caps. The caps sit on each end of the spring (the raised side of the spring caps sit in the spring).
If you take the Vortech SFMU apart (remove the six allen key screws), the unit is as follows:
Silver Top Cover --> Top Spring Cap --> Spring --> Bottom Spring Cap --> Diaphram --> Bottom Blue Vortech Unit
Measure the diameter of the three disks. This way you can tell which one is inside the vortech. They should be the following sizes (in inches) 3.62, 2.72, 2.47, 2.22. From the looks of it, the 3.62 disk is installed in the vortech. The largest disk does not use a ring and that is why you have only three rings but four disks. If any of the other disks were installed, you would only have two rings (in your picture there are three).
I am using the 2.72 disk with the Vortech Optional Hard Spring. The spring that you showed in the one picture with the spring caps is not the hard spring. The hard spring is dark in color (dark redish) and much shorter than the silver spring. You may already have this spring installed in the vortech since you have a picture of the silver spring. The hard spring allows for a faster rise rate per pound of boost. (double check by taking the vortech apart)
As for adjustments, the only adjustment I made is to the idle pressure (set by loosening the jam nut on top of the vortech and using an allen key to turn the screw). The other adjustments are for fine tuning. They are a bleed port (lowers the rate of gain, alters slope), boost port (sets maximum fuel pressure under boost), vacuum port. I have not adjusted any of the optional ports yet.
#35182, "RE: Just got SFMU but now what ? (is it complete)" In response to Reply # 1
hey kteclipse thanks for the info really helped.
When i opened that thing everything few out of there heheheeh lolz. But the spring that was in there was even bigger. So if this is not the stiffer spring the what 2 Springs do i got??? Does the SFMU bring 2 springs ?? to interchange
check it out
Now what else do i need to tune with this, Gauge and if so wich do i get.
Now from what i saw inside it was the largest disk should i keep that in there. I am trying to run 5psi on a t3/t4 turbo?
The optional part # for the stiffest spring available is listed in the note on the bottom of page 1. It is part number #7X100-050. For 5 psi, I would use the 2.72 disk and hard spring. That setup will provide ample fuel.
I have never installed the silver springs so I do not know the WOT pressure rates. From reading the Vortech SFMU instructions, the Standard Spring (short silver one) has a maximum static fuel pressure of 50-60 psi. Static Pressure is fuel pressure at atmospheric conditions - no vacuum (vacuum line not connected). It will be 6 or so pounds higher than idle depending on where you live and then drop once you connect the vacuum line. I am not sure whether or not this spring will allow you to achieve a 50 psi idle (idle can be in the neighbor hood of 47-50 psi, I like to set it rich since our cars like to run rich). The Second spring (longer)can provide a higher idle pressure so I would start with this one if you don't want to purchase the optional spring.
I would hook up a fuel pressure guage (try to find one that has a maximum pressure of at least 100 psi on the guage) and run it under the hood to the front windshield (wire tie it to the windshield wiper and only close the hood so it latches - don't want to pinch the hose). Any auto parts store should have them - make sure it is for fuel. When you go under boost, see what your fuel pressures read. I believe for 5 psi you would want at least 80 psi of fuel pressure. Always start of rich and tune your way down (shoot for 90 psi at WOT). If pressure doesn't get that high with the silver spring installed, you will have to get the optional spring or run the next size disk.
The charts on the SFMU page are not easy to use because they do not tell you which spring they have installed. I assume it is the original short silver spring. If you look at the graph at 5psi, the 3.62 disk does not appear to even reach 70 psi.
#35187, "RE: Just got SFMU but now what ? (is it complete)" In response to Reply # 6
Na man its cool. I can get one somewhere else. I told him he didnt have to save it for me. I was just wondering so that I know that I have to start looking else where. I might just buy a new one next week.
#35188, "RE: Just got SFMU but now what ? (is it complete)" In response to Reply # 7
Sorry,
I meant if you use the 2.72 disk with the tall silver spring and the fuel pressure isn't high enough at idle (50 psi) or WOT (80 - 90 psi) try the next size up disk which is the 3.62. Like I said, I really haven't messed around with all the disks.
I took the advice of others on this board who recommended the 2.72 disk and the hard colored spring and it has worked flawlessly.
There are plenty of archived topics discussing the SFMU.
Search
Printer-friendly copy
2 Users in Chat
, It is really big, they look smaller in pictures though i was amazed on the size on it 
