Walbro/Holley GSS315 1G 255 L/hr @ 40 psi pump, for 12v : 50 psi -> 54 gal/hr, 60 psi -> 49 gal/hr , 70 psi -> 40 gal/hr

Walbro/Holley High Pressure GSS341 1G 255 L/hr @ 40 psi pump, for 12 V: 50 psi -> 54 gal/hr, 60 psi -> 50 gal/hr, 70 psi -> 45 gal/hr

Supra Twin Turbo Denso 260 L/hr pump for 12.5v: @ 43 psi 68 gal/hr, @ 73 psi -> 50 gal/hr (serious *****)

RX7 3G pump : @ 50 psi -> 48 gal/hr , 60 psi -> 43 gal/hr, 70 psi -> 34 gal/hr

Endyn Bosch, for 12v: @ 50 psi 53.3 gal/hr , 70 psi -> 50 gal/hr (serious *****)

Paxton -> ?????? for a mustang or chevy there's lotsa info but for import application, good luck finding info.

Okay, so I will be running all motor 12:1 compression and 270 injectors. I prefer to go the pump route and give volume rather than using godzilla size injectors and using pressure. Need less to say I'm nervous with the compression number. The big names everyone asks here suggested:

Dan Ponze- Supra TT pump

Lip- Supra or RX7 OEM pump, or Paxton

B18CXR - Walbro HP

sgt - uses Paxton

SMSP - Endyn Bosch

Thanks for your wisdom and experience gentlemen.

Can anyone who has run an upgraded pump tell me if upgrading from a GSR/ITR OEM pump with that much compression runs you too rich or was it worth it and which pump do you recommend with a rationale? Your experiences would be very much appreciated. Thanks in advance.

Some issues to consider: The number of amps drawn by the Walbro is relatively high and I hear they're more noisy (in tank or inline) than the others. The non HP walbro heats up and craps out after 1 min of hard running for the folks with boost but I'm not running boost. I won't be doing the AN connections and lines...just good old OEM. Inline (external) is a lot easier an install against the unibody parallel to and left of the tank than dropping the tank and putting in an intank. Has anyone used a collector tank just after the pump to smoothe out the flow and dampen the noise?

cheers





[Modified by Michael Delaney, 6:07 PM 6/17/2001]

 

I dont understand.
You want more fuel by just getting a bigger fuel pump?

You wont get anymore fue flowl because the injectors are still flowing 270 and the more volume you are pumping is going right back to the tank because your fpr is bypassing it back. There is no way around it, you need bigger injectors or raise the fuel pressure to get more fuel into the motor.

The bigger pump is when your stock pump cant keep up with the flow demands that your big injectors(or raised fuel pressure) is demanding.

 

He is looking for a fuel pump that is efficient at high levels of PSI. Raising the PSI in the rail effectively raises the flow rate of the injectors.
RC has an equation for this.

Jason

 

thank you for the explanation and rationale for getting a pump...it'd be nice not to run at near 80 % duty cycle all the time, as well. The pressure vs volume thing is pretty standard amongst racers. You hear these guys run 70 psi FP before moving on to 310's or 370's injectorwise. My calculated BSFC is around 0.34-0.37.

from the RC Engineering website







[Modified by Michael Delaney, 6:57 PM 6/17/2001]

 

You could always run any of the pumps listed and a Volvo/VW CIS injection pump inline, they were good for 130 PSI. Not sure of the volume they provided, but it is enough to provide for a 1100 hp Gran National.


Jason

 

Does the Volvo pump have any heating up and amp drainage issues? The knock on the non HP Walbros are that they flow quite well up to 50 psi and deliver 125 psi but heat up and crap out...you have to stop, let them cool down and then they return back to their old selves. The Walbro amp drainage vs OEM is depicted here:



Man at least with a stereo you get music...with a Walbro draining you just hear the pump buzzing.

 

Some of that "whine" will go away if you redo the power supply to the pump. The stock wire is not able to provide 12V at the pump. Using an 8 gauge wire, you can make the pump run quieter and also run at a higher flow rate.
Using this gauge wire from the battery to the pump can provide between 13 and 14 V. Thus making the flow rate go from 255 LHP to about 280 LPH at 40-43 PSI.

Jason


[Modified by dogpile5, 8:00 PM 6/17/2001]