Dual Pumps Anyone?
12-26-2002, 07:08 AM
#1
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Join Date: May 2002
Location: Okinawa, Japan
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Got them both in. Easy as pie(almost). I had to ditch the front strut tower bar(fuel pressure regulator got in the way) but what the hey...
Okay. This is what I did.
Took the stock fuel pump assembly with stock fuel pump in place. Bent the low gas sensor out to make room for the second stock pump. Put the 2nd stock pump next to the first and use a hose clamp to tighten them down to each other(One on top, one on bottom). Jumpered a wire from the positive terminal on the first pump to the positive terminal of the second pump. Did the same for the negative. Put a piece of -6 steel braided hose between the stock return line and the 2nd pump and hose clamped the two ends. Now you have changed your stock return line into a feed line.
Drilled a hole on the top of the assembly and put a -6 bulk head fitting on it. Ran -6 from there to the charcoal canister hard line from the front. This is your new return line.
Now on to the front.
Ran a -6 line from the stock feed hardline to the primary rail(mine was already tapped for -6 ends). Ran a -6 line from the stock return hardline to the secondary rail. Took both outs of both rails and ran them to an aeromotive fuel pressure regulator summit racing part AEI-13101. Ran the outlet to the charcoal canister line(the one remaining line).
I primed the pump several times. I ran the return line, but did not connect it up. I took the return line and ran it to a bucket so that it would flush all the crap out of the chacoal canister line out. Once I was satisfied that it was clean, I connected the return to the bulk head fitting.
I went to start the car...nothing. When I put my foot on the gas, it fired right up. It idled, but I was getting really low fuel pressure. Once I hit the gas, I would get instant fuel pressure.
The problem was that the stock FD has a relay that turns the voltage to the pumps from 6 to 12 volts when you hit the gas. To remedy this, I attached a 2nd relay to the pumps on the outside. Now my pumps both run on 12 volts constantly...which raises the pressure of both lines.
I had the ND fuel pump and the walboro low pressure fuel pump. With 550cc primary and 1600 secondary injectors, I would lose fuel pressure with the ND pump as soon as the wastegate opened up(it would go as low as 30 psi). With the walboro low pressure, I would lose fuel pressure at about 5500 to 6000 rpms(at about 6500 rpms fuel pressure would be about 37 psi). Now with the stock pumps, I can rev safely to 8000 rpms with out one dip in fuel pressure.
Okay. This is what I did.
Took the stock fuel pump assembly with stock fuel pump in place. Bent the low gas sensor out to make room for the second stock pump. Put the 2nd stock pump next to the first and use a hose clamp to tighten them down to each other(One on top, one on bottom). Jumpered a wire from the positive terminal on the first pump to the positive terminal of the second pump. Did the same for the negative. Put a piece of -6 steel braided hose between the stock return line and the 2nd pump and hose clamped the two ends. Now you have changed your stock return line into a feed line.
Drilled a hole on the top of the assembly and put a -6 bulk head fitting on it. Ran -6 from there to the charcoal canister hard line from the front. This is your new return line.
Now on to the front.
Ran a -6 line from the stock feed hardline to the primary rail(mine was already tapped for -6 ends). Ran a -6 line from the stock return hardline to the secondary rail. Took both outs of both rails and ran them to an aeromotive fuel pressure regulator summit racing part AEI-13101. Ran the outlet to the charcoal canister line(the one remaining line).
I primed the pump several times. I ran the return line, but did not connect it up. I took the return line and ran it to a bucket so that it would flush all the crap out of the chacoal canister line out. Once I was satisfied that it was clean, I connected the return to the bulk head fitting.
I went to start the car...nothing. When I put my foot on the gas, it fired right up. It idled, but I was getting really low fuel pressure. Once I hit the gas, I would get instant fuel pressure.
The problem was that the stock FD has a relay that turns the voltage to the pumps from 6 to 12 volts when you hit the gas. To remedy this, I attached a 2nd relay to the pumps on the outside. Now my pumps both run on 12 volts constantly...which raises the pressure of both lines.
I had the ND fuel pump and the walboro low pressure fuel pump. With 550cc primary and 1600 secondary injectors, I would lose fuel pressure with the ND pump as soon as the wastegate opened up(it would go as low as 30 psi). With the walboro low pressure, I would lose fuel pressure at about 5500 to 6000 rpms(at about 6500 rpms fuel pressure would be about 37 psi). Now with the stock pumps, I can rev safely to 8000 rpms with out one dip in fuel pressure.
12-26-2002, 03:53 PM
#4
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Join Date: May 2002
Location: Okinawa, Japan
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Originally Posted by 93 R1' date='Dec 26 2002, 10:43 PM
:bigthumg: :bigthumg:
I'll probably end up doing this but with the supra pumps instead.
I'll probably end up doing this but with the supra pumps instead.
I went with the dual fd pumps because of one thing...price...People were practically giving these things away(they did give them away). The average price of the supra pump is $200 from what I've seen. For that price, you could have gotten 2 walboro pumps and have 510 lph...
...or you could have spent that on other mods. If you can get the supra pump for free or stupid cheap($50 or less) then do the supra pump. But with the stock FD pump being so widely available...it's MORE than enough fuel once you have 2.
12-26-2002, 11:26 PM
#10
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Join Date: May 2002
Location: Okinawa, Japan
Posts: 4,928
Originally Posted by 93 R1' date='Dec 27 2002, 09:46 AM
Not too sure of the flow on the supra pumps but if Ray can make 700 to the wheel on 2 of them then its good enough for me :bigok: