BC

I have basically decided on a fuel cooler. The setup on the car requires that I have alot of "mass" in the fuel delivery and return piping, as some is of course rubber, and some is aluminum, but of a thickness that I feel its safe. The Fuel rails are huge beautiful rods of aluminum.

Fuel cooler comes into play here, but I don't want to do something unsafe. The Fuel coolers I have seen are copper pipe and fins, but what if a rock or something hits it - I have to protect it from that situation, but still provide much needed air flow.

Any pictures of what has worked for you guys? Maybe a good size wire cage around it with a fan attached to augment airflow? I was planning that for the gearbox oil and engine oil coolers.

BC

To reduce pressure, I was planning on putting it in on the return side:

http://www.flex-a-lite.com/auto/html/fuel-coolers.html

chrisp

Help me understand why a fuel cooler is needed. I know the benefits of a cold vs warm charge but if the fuel is already at ambient temp and the air going through a cooler is by definition at ambient temp as well how does it cool the charge? I'm probably just not understanding where the heat is coming from.

Professor Helmüt Tester

Why would you need a fuel cooler ? Does it make any measureable difference at the point where the air/fuel charge swims by the valve (which is where it would count, if at all) ? If it doesn't, why bother ? Even if it does, why bother ?

BC

I was attempting to counteract some evidence by other individuals which which I have spoken about how hot the fuel really gets under our hoods. I am concerned about the heat soak aspect, as well as the "drifting tune" of fuel which would start to increase gradually during a day of track driving in my native area (SoCal and Norcal). As I am doing with the gearbox oil cooler, and the oil cooler, and (ahem) the aftercooler for the supercharger, - the idea is to keep the tempatures under control, and within certain parameters. Outside of constancy, and the issue of heat soak of fuel on shutdown and restart, those were my only reasons.

Past OEM functionality, I have added a good deal of "thermal mass" to the fuel system, and I don't want to run into problems.

I can circumvent the issue by tuning the VEMS to start the car hot with a totally different mixture, and that would probably work, but the info I have received says that its a very large change that is needed.

Also, the car had one originally, which ran through an AC cooled heat exchanger, and since the AC will be either gone totally, or in a very reduced plumbing capacity (again, hot tracks), I was planning on replacing that cooling capacity somehow.

chrisp

The A/C cooled one makes sense because the cooling charge is below ambient.

Will it fix heat soak since by definition there is no airflow when the car is at rest and that radiator thingy will be at whatever temp the engine bay is anyway?

It won't fix vapor lock since the radiator doesn't see airflow at rest.

My guess is the fuel flow (speed not volume) is pretty significant through the fuel lines - something to the tune of 15 gallons per hour through that little hose. If you insulated the fuel lines in the engine bay then you could probably keep the fuel temp going into the rail pretty close to the temp leaving the tank. At full song my guess (a wild *** guess at that) is that the fuel is only traveling through the engine bay hoses for seconds, not minutes.

if you can put the fuel radiator in something cold (the A/C design you mentioned) then I think you are on to something good, or at the very least restoring the factory system. if you could get it really cold (like packed in dry ice) then you may even see a significant power boost.

Professor Helmüt Tester

Only fix problems that you've encountered on your car. Don't fix problems that others are speculating about, or you'll spend all your time chasing imaginary demons. If it's an engineering execise...well...fine...but don't be led down a path trying to fix a problem that hasn't popped up.

Racers/tuners/DE drivers/etc. are the biggest bull****ters on the planet. Ignore everything you hear in the paddock, and 95% of what you see with your own eyes.

If fuel perc. is a problem due to the heat in your end of the world, avoid the ethanol-tainted fuel at the corner gas station and buy race fuel.

If you're worried about 'heat-soak' during shutdown and off-times, a cooler won't help. If it's vapor-locking, run higher pressure in the rail and make sure that the system holds that pressure after 'key-off'.

BC

Thanks guys. As a half-way process, I suppose I could make better plans to insulate the fuel rails. And then if I actually do have a problem, I can add a cooler.

Thats a load off! I was running out of Fenders to put coolers in!
Oil
Trans
Aftercooler