Dual walbro fuel pumps?
06-04-08, 12:17 AM
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Dual walbro fuel pumps?
Does anyone in here have two walbro fuel pumps installed on their NA-T?
Seems like I'm running out of fuel here. 21psi is the max I could safely boost without going too lean.. so I figured I'd buy another walbro fuel pump.
Is anyone in here have two walbros in their fuel tank? If so, did you just splice the connection and turn it into two connections? (positive/negative)? Clamp the two fuel pumps together, securing them in place? T off the fuel line inside the tank? Any tips, comments, suggestions would be great. Thanks in advance
Allen
Seems like I'm running out of fuel here. 21psi is the max I could safely boost without going too lean.. so I figured I'd buy another walbro fuel pump.
Is anyone in here have two walbros in their fuel tank? If so, did you just splice the connection and turn it into two connections? (positive/negative)? Clamp the two fuel pumps together, securing them in place? T off the fuel line inside the tank? Any tips, comments, suggestions would be great. Thanks in advance
Allen
06-04-08, 01:28 AM
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I dont know if it will fit the sc but I would ask over at clubna-t http://clubna-t.com/forums/showthread.php?t=3260
06-04-08, 06:21 AM
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You can not just splice into the existing oem wiring harness in use for one pump, it'll over heat the wire, underpower the pumps and bad things will happen.
You did not mention what injectors you have. The 550cc would be having some duty cycle issues at your whp number and that nice single you have would out-flow your injectors. I take it that you've done the fuel-dampner bypass mod.
My 550's are being pulled in favor of 700cc top feed Blitz.
Supraforums is loaded with dual fuel pump threads, diagrams, hangers and info.
You did not mention what injectors you have. The 550cc would be having some duty cycle issues at your whp number and that nice single you have would out-flow your injectors. I take it that you've done the fuel-dampner bypass mod.
My 550's are being pulled in favor of 700cc top feed Blitz.
Supraforums is loaded with dual fuel pump threads, diagrams, hangers and info.
Last edited by SCoupe; 06-04-08 at 02:20 PM.
06-04-08, 06:55 AM
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i'd have to agree w/ scoupe. first thing to check is to make sure your not running out of injectors.
as for the wiring, i've got a dedicated 10 gauge wire to one denso. if i go 2 pumps, i would probably either upgrade the single 10 gauge to something beefier or run another 10 gauge for the second pump. that's my thinking right now but i haven't done much research on this yet. subscribing to thread...
as for the wiring, i've got a dedicated 10 gauge wire to one denso. if i go 2 pumps, i would probably either upgrade the single 10 gauge to something beefier or run another 10 gauge for the second pump. that's my thinking right now but i haven't done much research on this yet. subscribing to thread...
06-04-08, 02:02 PM
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This hanger didn't fit my 97 SC400. The bucket is designed differently inside the tank. I dont know if this was a 97+ change or an SC400/300 difference. I wouldnt suggest you cut the bucket to fit either.
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06-04-08, 03:26 PM
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The hanger was tested on a '94 SC300 and while it's tirght, it went in there. I reached in shoulder deep to make sure.
The bucket needs to be offset on the strap [as in the pics] and installed into the swirl pot at an angle. It's level to the road, but sitting at an angle in the slosh tank. If you ever have the tank opened, have a chance, can you snap a couple of shots of your swirl pot for me?Thanks!
Eric
06-04-08, 03:53 PM
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Theres definitely no chance Im going to be opening my tank anytime soon. The hanger would have worked perfect on my 93 SC300 but if you set the SC300 and my 97 SC400 stock hanger side by side, the design of the hanger itself is different. My 97 SC400 comes out straight then drops immediately straight down. Theres no kind of angle in it.
06-04-08, 08:38 PM
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Eric, Why don't you take a closer look into this...It may be an issue. I would have known this by now if it wern't for all the delays I have experienced in getting my car done. I would like to fix this issue before and not after I am ready to install thet fuel hanger...
Thanks,
Ryan
Thanks,
Ryan
06-04-08, 08:48 PM
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I have Precision 650cc injectors, one walbro 255lph fuel pump, stock fuel rail, and an aeromotive adjustable FPR (with gauge).
What is the fuel dampner bypass mod- and what benefits would that have?
I'm trying to avoid spending $300+ on a fuel pump hanger, considering both fuel pumps are only worth $190 combined.
Do you guys think I've reached the limit of the single walbro fuel pump? Wiring is stock, I haven't added a relay to ensure the high voltage yet.. maybe I'll do that prior to adding a 2nd fuel pump.
Al
What is the fuel dampner bypass mod- and what benefits would that have?
I'm trying to avoid spending $300+ on a fuel pump hanger, considering both fuel pumps are only worth $190 combined.
Do you guys think I've reached the limit of the single walbro fuel pump? Wiring is stock, I haven't added a relay to ensure the high voltage yet.. maybe I'll do that prior to adding a 2nd fuel pump.
Al
06-04-08, 09:34 PM
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Fuel Dampener Bypass Mod
imho, you've hit the limit of your Walbro pump as installed. You might get a little more flow if you do the bypass mode. The Fuel Dampener Bypass Mod will increase flow to the fuel rail by removing a major restriction in the fuel line, three banjo bolts and the fuel pulsation dampener. All of which conspire to meter fuel to the rail. The MKIV.com tech article with pix. http://mkiv.com/techarticles/fuel_by...ine/index.html
Look into the 12v mod, bypassing the fuel pump ecu and running a 10 gauge hot wire with a relay to your fuel pump, pumps want the best power supply they can get at max output. Take your pick: SC300 12v Fuel Mod w/ Pictures - FAQ or http://mkiv.com/techarticles/12v_mod/12v_mod.htm
imho, I'd lose the Walbro for a MKIV TT Denso fuel pump. Read the second paragraph in the "Conclusions" section at the bottom specifically about the Walbro. http://mkiv.com/techarticles/fuel_pu...t_2/index.html
Last edited by SCoupe; 06-04-08 at 10:21 PM.
06-05-08, 02:47 AM
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imho, you've hit the limit of your Walbro pump as installed. You might get a little more flow if you do the bypass mode. The Fuel Dampener Bypass Mod will increase flow to the fuel rail by removing a major restriction in the fuel line, three banjo bolts and the fuel pulsation dampener. All of which conspire to meter fuel to the rail. The MKIV.com tech article with pix. http://mkiv.com/techarticles/fuel_by...ine/index.html
Look into the 12v mod, bypassing the fuel pump ecu and running a 10 gauge hot wire with a relay to your fuel pump, pumps want the best power supply they can get at max output. Take your pick: SC300 12v Fuel Mod w/ Pictures - FAQ or http://mkiv.com/techarticles/12v_mod/12v_mod.htm
imho, I'd lose the Walbro for a MKIV TT Denso fuel pump. Read the second paragraph in the "Conclusions" section at the bottom specifically about the Walbro. http://mkiv.com/techarticles/fuel_pu...t_2/index.html
Awesome, thanks for the info. I did the "12v" mod (the first one) almost a year ago. Maybe I'll just leave that pump alone.. and run a relay to ensure the new fuel pump gets ~12v voltage.. how does that sound?
Does anyone know where I could get a (brand new) Supra denso fuel pump for the best price? thanks
Al