qwiketz

I'm from the world of mustangs and a lot of their systems don't utilize a hobbs switch. Other than requiring a bigger regulator, are there any downsides to not using a hobbs switch other than high fuel temps? Is there really a bump in fuel pressure when a pump kicks in during boost?

Also, what hobbs switch do you guys use?

Lonnies Performance

iTrader: (16)

If you have a properly sized return system, you can run both all the time. The negative result is a larger current draw on your alternator & higher fuel temps. The fuel has to absorb the additional heat from the pumps themselves, plus the heat from the engine compartment/fuel rails etc.
Some applications can experience pump cavitation on a hot day.

There is a reason fuel pump controllers are avaialble for all the big single pumps. Personally I do not like to run both continuously.

If done properly there is no need to run both pumps all the time & you will not have a large fuel pressure spike in your system.

Dean95z28

iTrader: (7)

Why doesn't anyone run fuel coolers? I have seen several styles that will fit right under the car. I think it will fix any fuel temprature problems.

Lonnies Performance

iTrader: (16)

You could, but why buy additional parts to fix a problem that can be easily avoided by only running 1 pump until you need both.

It's personal preference, but I've built a few hundred kits with hobbs switches to prove their function & reliability.

jhilb

iTrader: (4)

This just convince me to run a Hobbs on my 2nd pump then. I already have underhood heat issues, I don't need my fuel getting any warmer.

So how to wire a Hobbs on my 2nd pump and where is a good place to get the switch? I generaly understand the Hobbs switch, I think. It detects boost and throws a switch (which is throwing a relay which throws the 2nd pump on)?

Jeff