Hello,

I'm looking at making a homemade "boost-a-pump" system, to run my fuel pump on 16 or 18volts so i dont have to replace my 255lph walbro pump for my power goals.
It will be high/low switched either by boost pressure or by my ecu (Link G4 xtreme).

Do we have any resident circuit designers that could help me out with the component selection and design?

I already have an IC sorted. I'm going to use a basic Step-up step mode power supply, feeding into a Mosfet to control the high current load that will be needed. Full load @ 18v should be about 15Amps, but i want to build it for 20A.

I know i can buy these off the shelf for about $250USD, but i could probably build one for $30USD. I work in electronics for the living, so i can build it at work.
I just dont have the circuit construction experience.

Any help would be good!

Cheers, Mike

 

good question wonder why noone has any responses i am just wondering if the pump will get too hot to cause premature failure

 

http://www.kennebell.net/accessories...boostapump.htm

people use them to great success.
i do electronics for a living so $400NZD to me for a powersupply is not an option when i can just build my own for a 1/10 the price

 

when do you think you will be making one? It seems like a good idea and i would love to see some results after you do it.

 

i was going to build one at work. i had a friend that did a degree in electronics etc, but he moved workplace so i haven't found the time to pick his brain about it yet.

It's all good on paper but i just need to do a prototype i guess and see how it goes!

 

I have the bell boost a pump. It may be easy to make circuit to boost the volts to 18v. But maintaining it at 18v even when battery is at 10v is the complex part.

i choose this because i didnt want to chop up fuel lines to add a second pump. I was disappointed with results boosting the walbro 255. the flow only increased by one point. A/F went from 11/1 to 10/1 with the boost a pump. twin pumps will drop a/f 2-3 points.

adding voltage has no ill effect on motors. they run more efficient on less amps given same load.

 

the circuit will be turned on and off when the car is on, so voltage shouldn't drop below 13volts.

as you should know this, you'll only get a change AFR when the pump is struggling in the first place. So saying the AFR change was less than desired, is dependant on the overall fuel flow required. AFR will only change is the fuel pressure changes (if IDC stays the same).

running a fuel pump at a higher voltage will just cause it to spin faster. so it will flow more fuel at any given pressure.
I think your last statement is a little off. The pump is a set resistance, if you add extra voltage, it will draw more current. Thats why the boostApump turns on at a set boost pressure, so that the pump isnt working harder where the extra fuel flow isn't needed

Cheers, Mike

 

maybe you misunderstood my last statement. I was referring to joules law. P=VI
in this case P=Power= amount of energy needed to flow fuel. V=volts. I= current.

500hp requires a set fuel flow. That does not change. If P is constant when you raise V from 13 to 18 then less I (current) will be needed. Thus the pump becomes more efficient and is not working as hard.

The boost a pump maintains 17.5V even if your alternator dies. Its a nice feature. The factory voltage at pump varies with ancillaries that are on. and goes way south when alternator dies.

There are people making circuits for fuel injectors that raise volts to 18-30V range. With fantastic results. I suspect the next tool to pop up will be a box that does both.

 

well it still requires the same amount of Power to run. what you said is theoretical because once you increase the voltage, the current will increase proportionally because the motor is a set resistance/impedance.
i understand what you are saying here, but i dont really think it's relevant.

yeah that is cool. i dont think that'll really bother me though, i can set voltage limits on the ecu when the car is running etc.

do you have any links etc? i'd love to get my hands on some schematics. I know the do 16v systems for ignition coils, that way the spark energy is more consistant because the feed in is regulated and you dont need to adjust dwell time to compensate etc.

 

Check these out:

http://en.wikipedia.org/wiki/Boost_converter
http://www.daycounter.com/Calculator...lculator.phtml

 

here's what i was thinking





using the high current mosfet for the output, it needs to be able to handle the peak current flow, which for my scenario is about 100amps.

i just need help with the other components and someone to bounce ideas off