I uderstand the Walbro pumps are voltage sensitive. I already have the hotwire kit where the pump is fed directly from the alternator.

Would something that increases voltage even more be beneficial? I know MSD and others have a boost a pump which is adjustable to increae voltage as rpm climbs. What about something like this that increases voltage constantly:

http://www.performancedistributors.com/minivipss.htm

I know its marketed toward ignition........

Would this decrease pump life?

 

It is a DC motor so as you increase the voltage applied to it the speed will increase and pump more GPH of fuel. More voltage would only be beneficial if you need more GPH than you currently have at the set voltage.........do you need more GPH?

That link shows that the device can't handle more than 6 amps (see the red text). The package size alone indicates that also. Notice they only talk about 18 volts and no current rating. You will be over 6 amps of current at 18 volts with the Walbro pump.

Some vehicles turn on a second pump at high rpm and/or boost.

Yes, any increase in pump voltage will make the pump spin faster and therefore it will wear out quicker. Think of it like an engine, if you hold it WOT it will wear out quicker but make more HP during the time it runs.

Usually only the higher voltage is applied at high rpm or boost when the extra fuel is needed or just run two pumps or a giant expensive one.
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Keep in mind that the ECM will decrease the injector PWs as the voltage increases. Sometimes the battery correction table for PWs needs a tweak.

 

The Walbro 255 lph pump is about 255/4.x = 64 GPH which is about 64 *5.8 = 370 lb/hr which is about 370 / .55 = 670 HP at 43 PSI fuel pressure and stock voltage.

How much HP are you making to need the higher voltage?

EDIT: Forgot to include the safety margin of 20% that I use: 670 * .8 = 535 HP

 

Thanks; didn't see the amp rating on that device.

Not to the point of needing more fuel; just trying to think ahead.

Think it would indeed help with ignition or just another version of snake oil?

 

You're welcome. I hear ya on thinking ahead. Having you pump connected right to the alternator is about the best setup. Depending on the vehicle, the alternator output to sense line is 0.1 to 1.0 volts. On my rig I see a 0.5 - 0.8 volt drop. You can play games with the alternator sense line to vary the alternator output.....but I won't go into that. So what am I getting at with all this?

If you measure the voltage at the pump with you alternator setup it is probably at 14 volts or higher so it is flowing around 70 GPH and stock fuel pressure. If you get into turbo/supercharge then things change because the fuel pressure is no longer referenced to atm. so GPH at a given fuel PSI it not as it would seem........in case you are thinking ahead of going boost.

Is that voltage converter worth $250.......NO WAY. A user would gain MUCH MORE spark energy by buying an aftermarket coil ($80) and ign. module ($60) for their stock distributor. If a user already had an aftermarket coil and ign. module and used that 18v converter module........it would probably burn out the the 18v module or possibly the coil or module. Anyway, that 18v voltage converter seems useless for a thirdgen TBI/TPI style ign. system.

EDIT: I am calling stock fuel pressure 43 PSI. If you are TBI at 12ish PSI then the 255 LPH Walbro will flow upwards of 700 HP.

EDIT AGAIN: I just noticed your sig. says 92 454SS with Wynjammer. That is the turbo-ish compressor run off an alternator setup, correct? How has it been it terms of performance (boost) and reliability?

 

Actually these questions are in reference to my 90 with the 496. Heavily worked Vortec heads with custom ground roller, 10.7 CR.

Currently running 42 psi with the TBI. External Aeromotive regulator, TB bored to 2.2" on an Edel MPFI intake (without the MPFI injectors). Walbro 255 lph pump in an S10 Blazer gas tank mounted behind the rear axle.

I'm currently using a complete big cap distributor setup from Peformance Distributors. I questioned them about using the voltage booster with my setup and they said it would work. I just don't know if I want to try that expensive experiment

The Wynjammer works good. I've lost one belt after after 5K miles. I got a steal of deal on it (basically new and horse traded plus a little cash ) Based on ET, it added about 100 hp.

The 90 pulled a 12.43 the first time I took it to the track several weeks ago and I'm sure its a got a bit more in it. 1.64 60 ft time to boot