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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Holden:
Sorry. I misread your mods.
I really doubt you are only hitting 88psi max FP with a JR FPR. Something sounds wrong. Either the vacuum hose to the JR FPR is not feeding it enough vacuum or your FP gauge is not accurate.
I've had FP gauges go bad myself. It's possible.
Do you know what boost you're getting? Maybe your only making 5psi in the manifold and that's why power and max FP are low.
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Well, I finally got the fuel pressure gauge working a few days ago. I had it all hooked up and the sending unit was leaking. They were back-ordered for weeks and I finally got one. Its quite hard to tell what the max pressure is because its a short sweep http://www.hostboard.com/ubb/frown.gif
I don't think its the vacuum hoses, but, I might pick some up at the parts store just to be sure.
My autometer boost gauge shows 7-8psi.
?
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fuknboostn
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I think alot of it is in your take off. In South Carolina we have an 1/8 mi. track and I ran stock boost with no tuning on street tires and ran 2.13 60ft and 8.94 1/8 mi. times. I think my speed was like 80.xxmph. I would hope your car wouldn't be that much out of tune. You could just be spinning too much. Spinning can kill your E.T.
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As long as its fast!
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Regardless of driving ability or 60' times, trap speed is a fairly reliable indication of power.
With 7-8psi boost (which is what the JR FPR sees), the JR FPR will raise FP 35-40psi. This says your max FP is 93-99psi. That's not a bad range for max FP psi.
Since you're boosting the right amount for your setup, and it looks like your max FP is not bad, I'm out of ideas.
Wild guesses include:
- Valves out of adjustment
- Worn out ignition components (dist. cap, rotor, wires)
- Bad spark plugs
I'm stumped. Are you sure compression is good?
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Greg Holden
96 GSR, JSRC @10psi, All the Goodies!
Best 1/4 ==> 13.556 @ 105.29mph
My JRSC Install Site
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Holden:
Regardless of driving ability or 60' times, trap speed is a fairly reliable indication of power.
With 7-8psi boost (which is what the JR FPR sees), the JR FPR will raise FP 35-40psi. This says your max FP is 93-99psi. That's not a bad range for max FP psi.
Since you're boosting the right amount for your setup, and it looks like your max FP is not bad, I'm out of ideas.
Wild guesses include:
- Valves out of adjustment
- Worn out ignition components (dist. cap, rotor, wires)
- Bad spark plugs
I'm stumped. Are you sure compression is good?
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-I adjusted my valves the weekend before the supercharger went on
-I replaced distributor cap & rotor at the same time
-I replaced the spark plugs at time of install
I checked the compression before I bought the car last december. It was 200 across the block at that time with 110k miles. The car currently has 120k miles. The supercharger has been on about a month.
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fuknboostn
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I went to a local drag strip last night and was able to make 3 passes. They ranged from 14.6 - 14.8.
Here is my best pass
60' - 2.326
330 - 6.309
1/8 - 9.520
MPH - 76.92
1/4 - 14.605
MPH - 94.54
I have a 94 GSR with the JRSC @ 6psi. (120k miles - compression 200 across the block)
I went drag racing 6 months ago and I had:
AEM CAI w/bpv
DC 4-2-1 2pc header
2.25" testpipe
greddy evo catback
stock gsr wheels with bald dunlop all seasons (~33psi)
The temperature was the same as last night (50-60 degrees) and my best run was 15.080 @93.95mph (diff track though)
Since then I've added ES motor mount inserts, circuit 8s with 205/50/15s kumho 712s (had 25psi last night), and pro kits/bilstein setup.
I had some major tractions problems, i spun off the line and once I hammered it in first I got really bad wheel hop past 5k rpms, id shift into 2nd and get wheel spin for a second or so, then then the same thing happens when shifting into 3rd (wheel spin for a second). I launched between 2000 and 2500 rpms and when i start spinning really bad, I actually let off the gas and gradually got back into it. I shifted at 8000rpms, maybe a little less into 2nd (according to stock tach).
I think my timing may have something to do with it, its probably around 7-8 degrees. I just tried to get in the middle of the 0 and 14 degree markers.
I have a 3" short ram and a gss-342 (58psi static), complete stock exhaust.
let the suggestions fly!
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fuknboostn
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If it makes you feel any better, I had pretty much the exact same setup down to the tires and tire pressure and I ran a 14.7 @ 96.5 MPH.
It seems like your static and vac. pressures are high. That's what happened to me when I first put my GS-342 in but I didn't see a fuel pump in your sig. Stock GSR vacuum FP is ~42 and static is ~52. You might try getting a B&M or Vortech to lower your static/Vac. FP.
I'm starting to realize that dyno tuning is pretty essential. I used to think that I could fairly accuratly gauge how rich I was at WOT by the amount of green bars on the A/F gauge but after extending the mechanical FP gauge under my hood so I could feed it through the cowl and hood I saw that my max FP's were way too high. Although you have an electric FP gauge to tell you this and your max FP's don't seem all that bad.
A little more timing might help. If you're right in the middle of TDC and 14 deg that's pretty low. Mine is a few virtual ticks to the right of the 14 deg mark, but you may begin to detonate with any more timing.
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Bill Winters
Houston, TX
'94 GSR - JRSC w/ ENDYN stepper pully, Cartech 20005 FMU, AEM fuel rail, B&M CommandFlo, HotShot 3" short ram intake and homemade CAI
(GS-342 and RC 310's soon to be installed)
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 5 Liter Eater:
If it makes you feel any better, I had pretty much the exact same setup down to the tires and tire pressure and I ran a 14.7 @ 96.5 MPH.
It seems like your static and vac. pressures are high. That's what happened to me when I first put my GS-342 in but I didn't see a fuel pump in your sig. Stock GSR vacuum FP is ~42 and static is ~52. You might try getting a B&M or Vortech to lower your static/Vac. FP.
I'm starting to realize that dyno tuning is pretty essential. I used to think that I could fairly accuratly gauge how rich I was at WOT by the amount of green bars on the A/F gauge but after extending the mechanical FP gauge under my hood so I could feed it through the cowl and hood I saw that my max FP's were way too high. Although you have an electric FP gauge to tell you this and your max FP's don't seem all that bad.
A little more timing might help. If you're right in the middle of TDC and 14 deg that's pretty low. Mine is a few virtual ticks to the right of the 14 deg mark, but you may begin to detonate with any more timing.
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I've been staring at my autometer fuel pressure gauge and it looks like its around 50psi at idle and around 88-90psi max. I set the static pressure at 58 according to my underhood B&M (however its not currently hooked up until I fiddle with all my little brass fittings and get both the sending unit and the gauge to fit).
I checked on a couple of those timing lights and they are like $70 for an adjustable one... Would that money be better spent on a BTC or something?
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fuknboostn
