I got all the gauges in (a/f egt, boost, fuel press) and im having some probs with the HRC regulator. I have that little brass nob turned almost all the way out and at WOT my pressure still hits 100 psi and my air/fuel gauge reads almost 1 volt. My egt is right around 1450-1500 deg F (mounted at 4 runner). Going by the a/f gauge I think I should lean it out a bit, but it doesn't let me. I do have the check valve installed properly btw. Any ideas whats going on guys??? Thanks in advance.

Matt
HRC Stage 2

hmm i am having pretty good luck with the FPR, my knob is turned out a little more than two, and fuel pressure is all good, but idle pressure is a little high, i dunno if you have the same problem, but if i set the idle pressure at say 50 psi and then turn off the car, and start it again it raises to like 68 or 70 or so, and after some driving say 10 minutes it is back down to 50psi DOH! hehe the only thing i can think of is that one of your brass fittings on the fpr is loose and leaking or one of the 4 allen head screws on the fpr may be loose, check the needle valve (brass thing) take it off with a wrench and then blow through it when it is open all the way and see if it is plugged, and try to clean it with gumout or something i cleaned it out and it appeared to work a little smoother and consistently!
lates!

Yea I think I'll try that. The problem you're having with the idle pressure is a bit odd. Mine is very consistant at about 57 psi. I wonder if your problem might be with the wiring of your fuel pump. Maybe the voltage is fluxuating... Thanks for the help.

Matt

I had the exact same problem with the idle pressure varying. It would vary with temperature. Idle pressure affects boosted pressure, so my fuel was never right. I got so sick of it, I got a Vortech S-FMU and haven't looked back since.


Corbin
'95 ESI-T
HRC + FMIC

Matt,
I'm having the same exact problems you're having. Even though my set-up is custom, No matter how far I turn it, when I hit boost, it goes over 100 of fuel, let me know if you figure out what it is!

Mick

my idle goes to 65 or so after i set it at 55.. i think boost pressure is still around 100

is that vortech unit solid? once you set it is it rock solid? and the rise rate, i saw on the web site it says 12:1 is stock, on an hrc stage II kit is that rise rate correct for our application
thanks for the info!

I have no experience with the regular FMU, but my S-FMU is ROCK-SOLID. The fuel pressure won't even vary one degree. I am very happy. You can get several calibration disks for it (one being 12:1). Pick a disk that will give you 50 psi at idle, 90 psi at 6 psi boost, and 110 psi at 9psi boost. That sounds like a 5.5:1 or a 6:1 to be safe. You might have to check to see if a 6:1 really adds 6psi fuel for every 1 psi boost (it may not be that perfect).


Corbin
'95 ESI-T
HRC + FMIC

To be honest, I am not impressed with the regulator HRC provides either. I believe it is a cartech unit (from what I can tell) and it seems to have a lot of these fluctation problems like being described here. From my personal experience and dealings I think the vortec unit is much nicer. I am going to note that HRC has changed the design from the ones I have initially worked with and I have not played with the newer designed fpr. (I saw this at the shootout on Jeff's car - his looked much nicer than my original one) If we have to run what is already a psycho fuel setup (100+psi on small injectors vs larger injectors with way lower fuel pressure which is how everyone should go in the long run) I would hope the FPR can handle it properly. In fact, it is very well worth people getting a permanent in car electric fuel pressure gauge to monitro this constantly to avoid unecessary detonation that can kill your piston rings.

MuRiX
97 Eclipse GS HRC Stage IV+
Sitting and collecting dust most of the time..
A.D.P.
http://www.murix.com

okay i took the hrc unit apart last night. it appears to be very simple. but i do not like the tolerances that are used. basically this is how it works. there is a chamber that fuel comes in to then in the center of this chamber there is a spout where fuel is returned to the tank. well, these two chambers are covered by a piece of sheet metal which controls the amount of fuel returned by opening or blocking off the center spout. well, the parts are not really precision at all. looking more i found out that on the top half of the unit there is a vaccum chamber that controls a piston that presses on this sheetmetal disk to control the amount of fuel sent back to the tank. The idle is controlled by a spring that presses down on this piston that is preloaded by the screw on top. The brass needle valve bleeds out boost pressure at a controlled rate which in turn controls our rise rate. the thing that confuses me about this unit is how it able to work given the tolerances and lack of attention to finish. it is rather simple though and it theoretically should work fine. The problem i am having is the damn fluctuation in idle pressure. i think i can attribute this to possibly the rubber gasket in between the halves. the piston does not directly push on the sheet metal plate, it has to push on this gasket which in turn pushes on the plate i think the elasticity in this gasket is what causes the damn fluctuation in idle, because other than that i can't think of anything that could be causing it! well i am going to blueprint the unit and see if i can get any better performance out of it, if i can't then i will buy the vortech unit cause given that the fuel delivery is the most important aspect of our turbosystems, i'm not about to use inferior means for fuel delivery