Are they worth anything?

Would it be any better to just run a trigger to a relay and use a 10ga wire to the pump? Whats included in these type kits and do they really do anything or only in theory they supply more power?

 

Do you know how to run the 10ga wire to the pump? I want to do this to test if my fuel presure droping at high rpm's is causeing my miss fire.

Also from what i read about the BAP's (boost a pump) they do really boost the fuel presure, however that is only for the one that cost around $200 or something like that. Alot of people use them for forced induction since they can be controlled by vaccume.
As for the cheap ones that hook up to your alternater i duno if they really work or not. It would seem like a pretty good idea since alot of cars lost volts at the hight rpm's.

 

I ran a KB BAP on a single Walbro 255 lph intank pump with the stock fuel delivery piping. Did not deliver for me and resulted in fuel starve. Added a second Walbro 255 pump in parallel (user 16 ga wire to power each pump- common 16ga ground) and a relay switch to turn on/off from the driver seat (most always run with 2 pumps on). Works very good with a regulated fuel return circuit (set 43psi). Also, replumbed all the stock fuel delivery with twin -6an AeroQuip socketless hose. Each pump feeds a Y block @ mid car floor pan near the old fuel filter area. -8an line to the motor compartment. Helps to cut a hole in rear floor pan for tank access, and, never did drop the tank. B. (97ss - 383-D1)

 

That's what a hotwire kit is. It has a heavy wire that goes directly from the alternator to a relay, then it uses the normal fuel pump wire to close the relay. The heavy direct wire increases and stabilizes the voltage at the pump so it maintains pressure better.
You can DIY but the kits from Racetronics are plug and play with Weatherpac connectors. No cutting and splicing with water resistant connections.

 

Seems like I could build my own hotwire kit for alot cheaper just some wire and a relay. Anyone make their own?

 

I just got one from a local speed shop from painless wiring. $25

 

A 16ga. wire for a fuel pump seems too small. The Handbook of Electronic Tables and Formulas recommends a max of 3.7amps for a 16-ga wire when power transmission/voltage is considered critical. That's very conservative, but I would not use a 16-ga wire on a fuel pump. Using a common ground means the current is doubled, making the ground wire even more suspect. Probably "works very good"... but with that much pump capacity, unless you are putting down over 1000HP, a weak wiring setup isn't going to show up as a problem. A 10-ga wire is recommended up to 15 amps. The Walbro 255 draws about 10 amps at 3-4bar pressure.

 

The problem is fabricating an electrical port thru the pressure bulk-head plate. I do not have a stock bulk-head plate. The stock bulkhead is flow restictive. I agree, larger conductor gage is prefered, but, look @ what gm uses (18 to 20 ga wire). It was a tough task to stuff all those conductors thru a bulkhead that did not leak pressure. So far... success. My design is no-way like the stock set-up. So far, it has worked for 4 years, and, the duty cycle is probably less the 20% for a street driven vehicle. I also run a rear mount battery. I've looked @ pics of the racetronix set-up. Not better than what I have relative to flow efficiency, (they use the stock bulk-head plate), but, you get what you pay for. Also, I have re-plumbed all the supply side which really helps unload the pump head pressure, and, lowers pump transient current spikes. I could possibly stuff 12ga conductor, but, 10ga would be a experimental task. Maybe I will rework the circuit this winter.