Everyone with bigger fuel pumps...what are your ma

[waveoff]

Just trying to see if my car is behaving normally by comparing with other people. I'm seeing 80 psi max. Here's my fuel setup:

GSS-342, Cartech FMU (bleeder closed), stock injectors, idle pressures are 48 psi w/vac and 60 psi w/o vac.

At WOT I get 2-3 green LED's on my autometer a/f gauge and no audible ping.

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Fred G.
'97 Civic EX supercharged http://www.geocities.com/motorcity/track/4059
Beech 1900D driver...2,558 shp, 10,000+ ft./lbs. tq., top speed 331 mph

[Mr Rogers]

80psi @ WOT

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98 GS-scR w/ 8psi JRSC, Walbro HO fuel pump, AEM cai, DC 4-2-1 one peice header, Thermal Exhaust, Skunk Works cam gears, J&S safeguard, RC 310's, Cartech FMU, Vortech regulator, H&R sports and KYB AGX's, and of course to slow down, KVR X-drill F&R rotors and Carbon Kevlar pads and V1 to signal the slowing down and soon to go on the "Juice" and a CF diet.
Best et ==>13.6 @ 103mph w/ 2.3 60ft

[1fstGSR]

22 psi at idle
43 psi at 0 in/HG
62 psi at 9.5 psi boost. (3.4 in pulley for now )
Will

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Smoking Vette's left and right, even if they put up a fight......

[Marc]

When I had the blower on my civic with the Walbro GSS-250 fuel pump/stock injectors I pulled 40 psi at idle, 62 at 0in/hg, & 85 psi at WOT.

My J&S air/fuel meter read dead rich at WOT.

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Marc
1997 Civic EX, Supercharged

[BlownSOL]

SH*T, when I put on the 3.4 pulley, I saw triple digits in fuel pressure 106 or so OUCH!!!

[fastfour]

I'm around 84psi @ WOT.

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94 Civic Coupe/LS Hybrid
JRSC@6psi
AEM CAI
DC 4-1 Ceramic Header
Test Pipe
GReddy PE exhaust
Magnacore 8.5mm Wires
MSD 6A
Skunkworks Coilovers
ACT 6 Puck
Turbo Convert

[MDA]

So im confused here .... because when i used to run a fuel pressure riser, i could get 80+ psi with my stock fuel pump... so why get a huge one ?

[JRCivic]

fastfour,

You want the SAME pressures as you had with the JR FMU... the only reason you vary (read lower the pressures) is if you have larger fuel injectors. Since you did not mention this change, you will want the same idle (static) pressure, same rise rate (5:1), and same max pressure under full boost.

Will's numbers look extremely low, however, understand that he is running 350cc injectors compared to the OE 235's.

To answer the question about volume vs. pressure... In any fuel pump, as pressure RISES, the delivered volume DROPS. Just because you have plenty of pressure DOES NOT guarantee that you have plenty of volume. For instance, at 85psi of fuel pressure, the JR fuel pump (Walbro GSS-317) flows only 17 liters per hour... it takes 74 liters per hour to properly feed a 200 HP motor. So, this particular pump will lean the motor out slightly under sustained high-rpm driving... like interstate racing. The high volume pump (GSS-342) delivers 128 lph at 85psi fuel pressure: enough fuel to support about 340 HP.
Also remember that the higher the base fuel pressure, the harder the fuel pump has to work. This increases the potential for fuel pump failure.


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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph