Speedtoys

What is this -doing- that it actually cools the fuel?

jcorenman

Air-con. The fuel flows through a sleeve around the freon return line, which cools the fuel when the A/C is running.

928mac

Now lets think about this. Your AC use's HP to run, but the cooler fuel allows more fuel to enter so really the HP is made back. Very Smart.
I would think that in the soutern states where it is very hot in the summer, it may stop the fuel from getting to hot.

Now if I am not mistaken, it is on the return line to the tank. That is the one thing that makes me wonder why?
Why not on the pressure line?

Speedtoys

Well, the A/C is on with defrost..so theres little interest in cooling the IN fuel in winter..but you still have VERY hot fuel on the return line.

Thats all I can come up with..just it fits the bigger picture better, on the return.

blown 87

It is used to prevent, or help try to prevent the fuel from boiling.

Eric Buckley

The cooler is not on the pressure/feed line because that fuel has not been heated yet. The idea of the cooler is to remove the heat that was added to the fuel by passing through the hot engine compartment, particularly under extended stop-and-go idle conditions.

928mac

Now what if you ran an extra evaporator on top of the air filter to cool the air

worf928

Helps prevent vapor lock (or so I hear).

Mike LaBranche

Hilton

The internals of the fuel cooler are actually a lot more complicated than I anticipated based on how innocuous it looks on the firewall.

Its designed to keep fuel temps in the tank down on hot days (i.e. when you'd need AC running) - presumably to reduce knock, and/or cavitation at the pump.

If you do a search, there's at least a couple of guys chasing big hp who've had fuel temperature issues (George's supercharged Open Road Racing car comes to mind) on their custom fuelling setups.