I have been told that the Supra Pump aka. RP fuel pump, is better than a Walbro 255 lph?
Why is this?

 

This is a common thing around here. No one has any data to back it up. I think becasue most people think that size matters and the Supra is larger.

I personally am going to run one walbro for my current setup, and if I need more fuel I will run dual walbros. It will still be cheaper than a supra pump. I personally think this is the best setup. A lot of jap tuners run this setup.

 

How do you run 2 fuel pumps?
Do you have to build a special bracket to hold them in the gas tank?

 

From the flow maps I've seen online the Walbro flows more at stock voltage. If you bump the voltage up on both pumps then the Supra pump flows more than the Walbro.....however I've also been hearing that the Supra pumps are getting premature failure (5-10K miles) when you turn the voltage up on them so I wouldnt bump up the volts.

Also, from what I've seen you could just about buy 2 high flow Walbro's for the price of a Supra pump

STEPHEN

 

i'll trade a supra pump for two walbros anytakers.. haha

 

the walbro makes my TII runs so rich at idle, (with stock computer/ fuel system) anyway the Supra didn't. I mean you could really smell the fuel.

 

Here is some info on tested flow rates on some different pumps. Info courtesy of Wade Lanham.


http://www.wvinter.net/~flanham/wlanham/fuel/pumps.html

 

I seen supra's make over 800 to the wheels
using 2 walbro's

There are some reports of walbro's failing
but I've yet to see any one that I know of, that has one fail. I run mine direct to the battery in the trunk via a relay and have had it for 2 years with no problems

I plan to run 2
when I get my new 10-second set up done

 

Kabooski.....What walbro are you running? I'm gonna upgrade my fuel system and I can get walbro pumps at cost. I was going to run a Supra pump but after reading this thread I'm going towards the walbro.

 

255lph High pressure
(The Supra pump aka RP is 290LPH)


2 Supras = 400+
2 walbros= $180

I plan to activate the second pump
only when hitting mid-high boost
and add a LED light when it turns on
so I know If it failed, I can let off

easy

 

How much hp can you safely run with 1 walbro?

 

475rwhp with a static fuel pressure of 42.7psi boosting 15psi with a 1/2 bridge. Higher pressure means less flow from the fuel pump, so If you have to boost 20psi to make 475rwhp then the pump might not supply enough fuel. I would say 450rwhp would be a safe bet. As a note, you will have problems with the walbro pumps if you try to run them off of the stock wiring. They absolutely do not like 6 volts.

Over 4 yrs of use and abuse on the 2 walbros in my car.

 

Using a Walbro #341 (high press 255ltr) esily low 400's rwh with NO fuel pressure drop.
Still using OEM fuel pump wiring.
I do have a switch for hot wiring the pump with direct battery voltage but has not needed it.

Later

 

Thats an excellent idea! Lets me guess; you plan on using a solenoid and pressure switch like on a water injection set-up to activate the pump?

 

I could , but I can use the aux of my E.M.S to switch it on/off

 

off topic:

But how would you do this? I want to do a similar LED warning light for my E-Fans.

 

D.F.
Napa sales a HOBS switch. Around 30$. Adjustable from 1-15psi. You can hook this switch on the ground side of a relay to activate the extra fuel pump. Already tried this. It did not work to well for me. Made tuneing vary hard. Had the second pump come on at 3psi. When the second pump came on the fuel pressure would increase to much. I ended up just running both pumps at all times.
chuck

 

Thanks chuck, but I meant the info on the LED warning light. I want to set it for my E'Fans.

 

My walbro has been sticking intermentaly and been staying one when the car is off. I just relized this about a week ago and ever since when i park I take the positive terminal off so it doesnt run. I have a haltech e6k, could my relay be sticking because it only seems to do it when its cold and wet. Also i had it on the wide band not to long ago and in 4th gear underload, above 5500 rpm it would lean out between 14 and 15 on the a/f gauge.
Help please
Thanks

 

At 13.5 volts, 70psi of pressure:
-MKIV supra turbo=230
-Walbro 341=210

At 12 volts, 70 psi of pressure:
-MKIV supra turbo=207
-Walbro 341=180

Why I choose 70psi:
-40psi fuel pressure gradient+
-15psi fuel line pressure loss+
-15psi boost
According to Max Cooper's site this system will require a pump that can flow 218L/hr at 70psi of pressure.
That should be enough fuel for more than 470rwhp, depending on how aggressively it's tuned.

Links:
http://www.stealth316.com/2-fuelpumpguide.htm
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

 

I put my Supra pump in this weekend.
First thing I noticed was it was a lot quieter than the Walbro and my car runs a little leaner at idle.
Haven't noticed any other difference even at 19 PSI.