To 12v mod or not to 12v mod? Walbro pump please help.

[Dylan JZ]

If your ecu works correctly (switching to 12v) theres no reason to do the 12v mod unless you like the extra noise of the walbro @ 12v. Its been a long time since I've used a stock ecu, but I think its based on TPS.

which is why mine remains the same..

 

[tissimo]

I thought that one of the purposes of this mod is to make tuning easier? If there is no purpose of this mod then why is tuning easier on the 12v mod and more challenging on stock ecu and fuel pump wiring?

My old 7m and 1j used it stock and I never had a problem.

The ecu should switch to 12v far before you're maxing out the pump at the lowered voltage, so you wont notice the switch at all.

 

[annoyingrob]

Is it better to have the 12v regulated to make 12v?

Or does it not matter if it reaches 13.8v?

Cheers.

Actually, the higher the better. Have you ever heard of a Kenny Belle boost-a-pump? They output 17v to the pumps to give them some more flow.

I ran a stock pump, on stock wiring, stock lines, all the way up to 400whp. That was about the upper limit, I was seriously running out of flow by that time. (85% duty cycle on my 800cc injectors )

If by 12v mod, you mean just disabling the stock system that switches between low and high voltage, I wouldn't worry about it unless it's not working. But if you mean re-wiring the pump from the tank right to the battery, it will make a world of difference. I now run both of my pumps straight off the battery, through a relay, and some 12ga wire. I have a lot more fuel than I did with stock power lines.

 

[chuckmuska2005]

Actually, the higher the better. Have you ever heard of a Kenny Belle boost-a-pump? They output 17v to the pumps to give them some more flow.

I ran a stock pump, on stock wiring, stock lines, all the way up to 400whp. That was about the upper limit, I was seriously running out of flow by that time. (85% duty cycle on my 800cc injectors )

If by 12v mod, you mean just disabling the stock system that switches between low and high voltage, I wouldn't worry about it unless it's not working. But if you mean re-wiring the pump from the tank right to the battery, it will make a world of difference. I now run both of my pumps straight off the battery, through a relay, and some 12ga wire. I have a lot more fuel than I did with stock power lines.

Good info.

 

[boosted1jz]

after doing some new research i have realized that the walbro is in more ways than 1 a POS, A. they fail fast, and B. you can pick up a factory style denso for a few bucks more and it pushes more fuel

go with a denso and you wont be disapointed....

also yes re-wire it and make it a 12v full time

 

[chuckmuska2005]

after doing some new research i have realized that the walbro is in more ways than 1 a POS, A. they fail fast, and B. you can pick up a factory style denso for a few bucks more and it pushes more fuel

go with a denso and you wont be disapointed....

also yes re-wire it and make it a 12v full time

Probably because of the people that make the immatations that fail horribly and are killing the walbro name. There are several guys in the supra community that have these pumps and make reliable horespower.

I myself know of the MKIV Denso pump as it is a good pump as well. However, the check valve feature on the pump is something that I don't want deal with.

 

[tsuper92]

after doing some new research i have realized that the walbro is in more ways than 1 a POS, A. they fail fast, and B. you can pick up a factory style denso for a few bucks more and it pushes more fuel

go with a denso and you wont be disapointed....

also yes re-wire it and make it a 12v full time

there's no dought the denso pump is nice,but not very easy to get two of them into the tank

 

[boosted1jz]

whats wrong with the check valve?

anything will fit with a lil redneck engineering LOL jk

 

[tsuper92]

you would need to cut the hole in the tank alot bigger.two walboro's are a tuff squeeze and there much smaller

 

[chuckmuska2005]

you would need to cut the hole in the tank alot bigger.two walboro's are a tuff squeeze and there much smaller

I was wondering how people with the dual walbros got them in the tank. I know they make a dual pump hangar but how in creation do you wiggle them in the tank?

 

[annoyingrob]

Who says you need to run them both in-tank?

I run a MKIV Denso in-tank, and a Bosch 044 in-line. As long as the pumps can flow enough fuel at lower pressures, there's no reason that a serial setup won't be adequate vs a parallel setup.

 

[chuckmuska2005]

Very interesting point. How well does this setup work for you?

 

[supraguy@aol]

Could someone explain this check valve issue?
Not sure which pumps have them, and what they do/ don't do.

 

[annoyingrob]

Very interesting point. How well does this setup work for you?

Very well. If you're not familiar with the flow charts of a Bosch 044, they flow a ton of fuel, even at stupidly high pressures. Feed them with a pressurized fuel stream, and they pump out even more.

Running two pumps in series won't get you as much fuel flow at free-flow, but you will gain a much more consistent fuel flow, that is largely uneffected by backpressure. If you have a fuel pump that doesn't put out a lot of flow at pressure (cough cough, walbro), then running two in series will gain you some significant flow when fuel pressures start to rise. This is expecially true if you're running through more restrictive stock lines. Imagine your motor running 20psi of boost, at a stock 38psi fuel pressure. Add in pressure drops across fuel lines, your pump needs to push against over 60psi of pressure!

People always jump on the "stock lines are too small" bandwagon, and throw some gigantic -8AN things in there, when simply changing out their pump for one with a better flow up top will often suffice.