Your're better off running a larger gauge wire from the battery to the fuel pump, to prevent any major voltage drop issues, resulting from too much resistance in the wire run. I think i read in a post above somewhere, that the cap will "put out" 20+ volts or whatever. This is entirely not so. Just because the cap may say 24 volts on it, does not mean it can take your normal 13.6 volts(+/-), and convert it up to 24 volts. A cap isn't a transformer. The voltage it puts out, is roughly the voltage that comes into it. A cap is ONLY usefull for a instantaneos current drain situation, eg a loud bass hit(when referring to car audio). They help to keep voltage steady during this transient, because the cap can deliver the needed current, for that brief time frame, which helps support the main car battery. You will notice less voltage drop at the bass hit, and also less dimming lights, ect..

A cap for a fuel pump is pointless, let alone a waste of money. Use the right gauge wire, a proper switching relay, and fuse it at the battery, and that is all you should need. Even these high pressure, high flowing fuel pumps we use, dont draw more than 10 amps at MOST. I use a 10 gauge wire fused at the battery, going to the back of the car under the seat. From there it goes to a relay, which is switched on by the stock fuel pump power wire(blue/black i believe). Another thing that is VERY important, is the fuel pump ground! If you have a tiny gauge ground wire on the fuel pump, or if you are using the stock fuel pump ground wire, this also can produce a lot of resistance, which almost negates even doing the re-wire mod. Use the same gauge ground, as you do power. Ground it to clean, BARE metal of the chassis.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)