Electronic engineers: read. Want to up the voltage to my fuel pump

[JaSSon]

Alright, I have a problem. There is no decent aftermarket fuel pump for my car. Walbaro makes one, but from what I hear it's complete crap and will burn out in a matter of months. -not an option. I COULD go with an '03 cobra pump, but that requires an '03 tank and that is $$$. My solution: increase the voltage to the pump. Something along the lines of a Kenny Bell Boost-a-pump, but cheap. I need to up it from ~14V to 18-20V, nothing drastic, just a little extra insurance. I'm assuming I would need some sort of coil, and I dunno what else. I think this should be a fairly simple little box. I have some EE education, but honestly, most of it has seeped out of my head. I would like this to be something that is usually bypassed, then when i need it, flip a switch and increase voltage to the pump. Anyone up to the challenge?

[Mensan]

Get an aftermarket fuel system if you plan on running any serious amount of power. Tank, lines, pump, and rails. Make it a return style as well.

[Dave1647545494]

you need to build /buy a transformer and then switch it you should be able to buy what you need at radioshack

[excell]

You are wrried about the Walbro failing but you want to run 20V to your stock pump?

[Guest jpurdy2003]

Originally posted by ComaPee:

You are wrried about the Walbro failing but you want to run 20V to your stock pump?

Our fearless leader has a point. I know too many DSMers who have fried their fuel pumps this way.

 

I don't speak Mustang, but the DSM community has nothing but praise for Walbro pumps, and they are a mainstay in DSM modification. Anyone else care to help him

[SHIEF]

That isn't a good idea. You'll fry your pump in no time. Even if it's just for a pass down the track. After a few of those your pump will be fugged. Just go with a Walbro if you want something in tank, I've never had a problem with them. Or change your pump to an external, but you'd need another car for a driver for a few. Take the tank out, cut a section out of the bottom of the tank and make a sump system with the pump under the back end of the car. So what I'm sayin is get a Walbro.

[BiG BeN]

i've had walbro255's operating flawlessly in 2 vehicles.it's a good pump for the money.

[dq driver]

whinebro 255hp = $90

standard pump rewire =$20

enough fuel to overrun my stock fpr = great

aeromotive fpr and an fittings = $210

 

I haven't had any problems, although I have heard rumors of them failing. It's hit or miss from the start though, they usually don't go bad 'in a matter on months'

 

It's fuel, don't cut corners

[gillbot]

Originally posted by luong88888:

It's fuel, don't cut corners

Originally posted by ComaPee:

You are wrried about the Walbro failing but you want to run 20V to your stock pump?

+1

 

You can do it if you want to though with a DC-DC converter from any electronics store.

[Mensan]

He can't use a walbro in his car. The fluctuating voltage will cause the pump to fail.

 

Jason, I have also heard that there is a Focus pump you can use as an upgrade. Check corral for details.

[Guest nevarmore]

Originally posted by Mensan:

He can't use a walbro in his car. The fluctuating voltage will cause the pump to fail.

Whats this voltage fluctuation? Is it unsteady voltage caused by a design flaw? Is it supposed to do that with a stock pump?

 

Its a Mustang. The aftermarket for those is second only to the aftermarket for the Chevy 350, there just has to be a solid fuel pump for the pony.

 

Would a generic, out of tank pump be inappropriate for this car for some reason?

[SHIEF]

Mensan- I don't understand what you mean by 'voltage fluctuation', because there is no "fluctuating" going on after you turn the key to an on position giving the pump 12V.

[Mensan]

This guy has a returnless system, which means that instead of a pressure regulator, the cars computer keeps the fuel pressure at the level it wants. It does this by sending a fluctuating voltage to the pump. More voltage=more pressure. It is only like that on 99 and up Mustangs. In a car like mine, the pressure regulator routed the excess fuel back into the tank. Mine is easier to tune.

 

INFO

[rl]

Mensan is correct, you CANT use a walbro pump, it will fail (and have horrible driveability, being a gear pump vs a turbine pump). Either go 03' cobra pumps and tank if you plan on making 400+rwhp, or get a BAP and install it to run full voltage ALL the time, BEFORE the FPDM, that way the EEC is still in control of the pumps but can feed the pumps 18.7v if it is needed to maintain pressure @ 100% duty cycle.

 

The stock pumps wont fail at 18.7v because they arent at it for very long. The walbro pumps WILL fail because they are not meant to be cycled and burn up.

 

IMHO, get 03 cobra pumps & tank., or just buy a BAP, it takes 2 minutes to install and works.

[rl]

Originally posted by Mensan:

Mine is easier to tune.

 

You mean yours is cheaper and easier to buy parts for, tuning a returnless system isnt any harder than a return style for any good tuner, not to mention you can make more power with a returnless system and smaller injectors, provided that delta pressure doesnt fall off (you can increase delta p based on engine load so the injectors act larger).

[JaSSon]

any idea on the cost of a BAP?

 

EDIT: If i wire the device (to increase voltage) inline between the ECU and the fuel poump, wouldn't the ECU still control fuel pump voltage? If the ECU sends more voltage through box I wanna make, then the pump sees more, if it sends less voltage, then the pump still sees less voltage.

 

IE: ECU sends 12V -[bOX]- pump sees ~18V

ECU sends 8V -[bOX]- ECU sees ~12V

 

And of course I would like the ability to bypass the box when I'm just cruising at highway speeds. It's the same principal as the BAP, isn't it? Also, I've heard the Focus pumps(dual pumps off the SVT focus) will drain the sump, ass will the avaiator (the apparent new option) and that sounds bad.

[rl]

Originally posted by DropTop:

any idea on the cost of a BAP?

 

EDIT: If i wire the device (to increase voltage) inline between the ECU and the fuel poump, wouldn't the ECU still control fuel pump voltage? If the ECU sends more voltage through box I wanna make, then the pump sees more, if it sends less voltage, then the pump still sees less voltage.

 

IE: ECU sends 12V -[bOX]- pump sees ~18V

ECU sends 8V -[bOX]- ECU sees ~12V

 

And of course I would like the ability to bypass the box when I'm just cruising at highway speeds. It's the same principal as the BAP, isn't it? Also, I've heard the Focus pumps(dual pumps off the SVT focus) will drain the sump, ass will the avaiator (the apparent new option) and that sounds bad.

If you put the BAP BEFORE the FPDM so it ALWAYS feeds the FPDM with max voltage then it will run like stock driving around, at WOT if it needs more duty cycle from the pump to maintain delta p then it will have 18.7v that it can feed the pump, if it needs to, verse the stock 12v that it can feed the pump. The EEC remains in control the entire time.

 

You're increasing the range of voltage that the EEC can send the pumps.

 

I've wired several of them this way and they work perfectly, you get no transition point from the BAP coming on because its on all the time.

[JaSSon]

Originally posted by rl:

If you put the BAP BEFORE the FPDM so it ALWAYS feeds the FPDM with max voltage then it will run like stock driving around, at WOT if it needs more duty cycle from the pump to maintain delta p then it will have 18.7v that it can feed the pump, if it needs to, verse the stock 12v that it can feed the pump. The EEC remains in control the entire time.

 

You're increasing the range of voltage that the EEC can send the pumps.

 

I've wired several of them this way and they work perfectly, you get no transition point from the BAP coming on because its on all the time.

Yeah, that's what I'm talking about, but on a home-made college budget.

FPDM=Fuel pressure/pump??

[rl]

Originally posted by DropTop:

Yeah, that's what I'm talking about, but on a home-made college budget.

FPDM=Fuel pressure/pump??

FPDM = Fuel Pump on Demand Module. The EEC sends it a reference voltage and it steps that voltage up. Think of it as a variable transistor on a large scale (thats the IDEA, but thats not how it works, it uses duty cycle, not voltage, to control the fuel pump).

[SupraGlue]

Originally posted by rl:

You mean yours is cheaper and easier to buy parts for, tuning a returnless system isnt any harder than a return style for any good tuner, not to mention you can make more power with a returnless system and smaller injectors, provided that delta pressure doesnt fall off (you can increase delta p based on engine load so the injectors act larger).

Return style systems that flow large volumes at a fixed voltage also have a nasty tendency to heat the fuel during extended drives. That of course changes the density of the fuel and can throw your tune off. I think that once the aftermarket is there in abundance, returnless systems are going to turn out to be simpler to upgrade.

[rl]

Yep! smile.gif Returnless is a wonderfull thing. smile.gif

 

I missread your statement at first.

[Mensan]

Fuck you guys. Mine is better. tongue.gif

[desperado]

Originally posted by Mensan:

Fuck you guys. Mine is better. tongue.gif

I would haveto agree that all things being equal, a fixed voltage return system is better. I think we discussed the whole flow thing a couple months ago, so I will only mention that and not get back into it.

 

Electric motors, in general, are designed to be operated at a specific voltage, and not variable voltage to regulate speed. This is especailly true of DC motors. There are motors that are designed to be variable speed, but they are stepper motors or AC motors that the AC frequency is varied to change motor speed. DC motors, that are run at too low a voltage, will burn out QUICKER than motors that are over voltage, but not by alot, and neither is good to do.

 

Yes, I know this is what the factory does, they replace a regulator, AN fittings, high pressure lines and a seperate tank fitting with a .30 transistor that will vary pump voltage and burn out the pump after a while, but they saved $40 building the car. Of course the charge more for the car, but it still costs less to make. And it will only be under warrenty for so long.

 

Point is this, quit screwing around with trying to do performance on the cheap. There are products that will do waht you are wanting to do already, MSD sells one for sure, look in the JEGs catalog near the fuel pump listing. Or bite the bullet, go with a bigger pump, and a return system. And as long as you build it right to begin with, and allow for as much return flow as flow out of the tank, you can put in a big pump, that will handle a way bigger motor down the road if you deside to build bog later on.