If anyone is going the route of adding fuel capacity via the Boost-a-pump, the correct unit is KB89064 which is the true "dual" unit. It is the more expensive one $459 list and the one that is usually used on the Ford Mustang GT500

thought I would just post here to save others the trouble of getting the wrong one initially like I did...

 

Reason is that when upping the voltage you increase the amp usage, and on our cars you would be getting close to 20 amps then (pending the voltage/pressure you choose). As the single BAP unit is rated 20amps, it’s safer to get the dual unit which is rated 40amps.

 

Upping the voltage is a means of overcoming voltage drop due to deficient wiring or a means of spinning the pump faster. If it is a case of excessive voltage drop, then increasing the wire gauge would be sufficient. For 20 amps, no less than #12 gauge on each power and ground lead. Of course, this is ideally all the way to the pump connectors so it would involve fabricating new link leads for the inside tank connections.

 

A single stock pump consumes only about 8 amps, so it’s not so much about voltage drops, but when upping the voltage/pressure the pumps could consume about 2 amps more, so the stock wiring is still sufficient for that.

 

According to one reference chart, a 10 foot complete round trip circuit (power + ground) needs #14 AWG at 10A to limit voltage drop to 3 percent. It would be #16 AWG for 10 percent.

If we are generous and say that the existing wiring is #16 AWG, and that the relay is seeing 14.0v, then the pump is experiencing 14.0v-1.4v=12.6v

At #14 AWG, it would be 14.0v-0.42v=13.58v

At #12 AWG, the drop would be nominal for 10 amps.

 

Electrics isn't my area, and although there are losses as you say, you need to up the voltage much more than you can recover by installing different wiring to cover for the losses (although as said, it depends on the pressure/flow you require). I wouldn't just put the BAP to the maximum 17.5 voltage either; set it to a voltage that sufficient for what you need.

PS I just installed a BAP, and iirc the outside tank wiring seems much thicker than a 16awg, would guess more a 14awg.

 

Kenne Bell says:

" When do I need to look at wiring size?

When installing any larger/higher amperage than stock fuel pump(s). Any pump that produces more fuel will use more (amps) and tax the stock wiring. The BOOST-A-PUMP is designed to work with stock wiring. Only a larger fuse is necessary. "

 

been there done that and blew up some nice engines!

now, when i'm considering a hi-boost engine and fuel system, i use a 10ga. wire run directly from the battery, and a 50amp relay, thats uses the factory wiring to activate the relay. no more hi-boost F/P drop, with data recording.

you could wire in the circuit with a BAP without any problems.

ever considered a rising rate FPR alsop

 

of course you have a proper digital A/F ratio gage with data logging?

if your gonna go for it,may as well do it right!

engine rebilds can get expensive.

 

How did you blow up your engine with more fuel?

I am planning on adding the GT500 Boost a pump. Yes i WILL have a digital A/F gauge installed at the same time, no data logging, just a gauge.

 

So this happened to you?? Please elaborate

 

I'm finding there are two Dual units, no adjustment but one model 17.5 v and competition model 20V

 

I think that link is for a single pump. Here is the link from Kenne Bell



Boost-A-Pump

 

Yes, there are only two versions:

single pump driver with adjustable voltage and

Dual unit which comes in either 17.5 V or 20V

the ad I had linked to was using the incorrect photo