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I wish I knew about this board before I JRSC'd my Integra!
Anyway, I'm running JRSC 6psi with CAI and DC headers and Greddy exhaust, everything else stock. I *just* installed a B&M fuel pressure gague and was shocked to set it floating at 90 no vacuum. I installed all the mods myself except the JRSC. My MIL/EC light went on shortly after the install and the code I get is running too rich (not a surprise I guess).
Questions: (forgive the stupid ?s please).
1) Why did the shop leave the stock FPR on? Shouldn't the JR FPR do the job? Seems redundant to me.
2) I need some ballpark FP recommendations for my setup. Help!
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Oh yeah, upgraded fuel pump also. Don't know exactly what I got out of my ignorance to ask.
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with 90 PSI static you may have a bad JR FPR. That wouldn't be the first time the board has seem that.
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Bill Winters
Houston, TX
'94 bone stock GSR
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BadAss,
First, welcome to the board.
Now, for your questions...
The stock fuel pressure regulator is retained because the JR FMU does not function in vaccuum... thus, you would have entirely too much fuel during cruise and idle conditions. Essentially, the stock regulator handles the adjustments from 30 in/hg to 0 boost... the JR FMU takes over at 0 boost and goes up.
Your static (vaccuum line unplugged from JR FMU and capped so as not to create a vaccuum leak) should be set at 60 psi +/- 2 psi.
Good luck.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph
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Ah, thanks JRCivic. Comprendo ahora!
Yes, I'm not getting warm fuzzies from the JR FMU. I was able to adjust the static down to 60 no problem, but when I go to boost, the B&M gets pegged!! It's my impression that the FP should gradually climb depending on how much boost I'm at. From the board reading I've done, it sounds like the Cartech unit it the way to go . . .
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Andrew West
2001 4-dr GSR, 6psi JRSC, DC 4-2-1, Greddy exhaust, B&M FP Gague
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Yea, the Cartech allows for a lot of adjustability. I had one on my turbo Civic and loved it!
I think the JR unit is a 12:1 riser (can anyone confirm this?) so 12*6=72 on top of your 60 static would be 132 PSI of fuel. The pressure in the manifold may be more than 6 so add another 12 PSI of fuel for every pound of boost the FPR is seeing but it doesn't look like you have a boost gauge from your sig. Both a boost gauge and A/F gauge would help in the tuning but getting the static down was a good first step.
I don't know why 12:1 FMUs are the norm. In the instructions for the 20005 FMU, Corky Bell talks about ~6 PSI for every PSI of boost on a turbo/sc convert car. 60+6*6=96 which sounds about right.
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Bill Winters
Houston, TX
'94 bone stock GSR
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JR's FPR is 5:1 I believe but you have to take the amount of boost seen in the manifold to accomodate for the higher readings.
Just like my boost guage hits 8-9psi on the 6psi pulley, the FPR is seeing 8-9psi also:
60psi @ 0 vac + [5(rise ratio) x 9(boost seen at manifold) 45 ] = 95psi or so depending on the accuracy of the JR unit.
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I had a JR FPR all of a sudden stick at 90psi between runs at an autocross. However, it would not adjust down.
Since your's DID adjust down, I'd give it a chance and get some data. Maybe it was just adjusted wrong when it was packaged.
Do you have any way of seeing FP at WOT?
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Greg Holden
96 GSR, JSRC @6psi, AEM CAI/RSR 4-2-1/Greddy PE, Cartech 20005/Walbro GSS-342/TPS Mod, JR BTC, KYB AGX/H&R OE Sport/ST 19mm Rear Swaybar
Best 1/4 ==> 13.937 @ 101.41mph
My JRSC Install Site
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No, I'm discovering that it's hard to tune anything without feedback!
The B&M filter gague pegs (above 100psi) on ANY amount of boost, I think. When I flick the throttle in the engine bay, it looks to jump from static to pegged without any in between FP range, which leads me to believe my JR FMU is screwed up. I don't have any internal gagues to help me out. My guess is I got it from the shop without them even measuring the FP. Hopefully it didn't screw anything up.
Also, the B&M isn't a steady reading (i.e. it doesn't fluctuate greatly but it shakes very quickly +- 5 psi around the actual pressure). I assume this is normal, but I don't have enough experience to know better at the moment!!
Thanks for all the help. I hope to return the favors to this board one day . . .
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Andrew West
Santa Barbara, CA
2001 4-dr GSR, 6psi JRSC, DC 4-2-1, Greddy exhaust, B&M FP Gague
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BTW, just found out I got a Walbro 255 fuel pump installed at the shop with the SC. At least they got that right.
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Andrew West
Santa Barbara, CA
2001 4-dr GSR, 6psi JRSC, AEM CAI, DC 4-2-1, Greddy exhaust, B&M FP Gague
