fuel coolers do they work???

[sirbabblealot]

Well i've been looking on the net and have seen a few rally cars and high performance cars with sort of like a small oil cooler in the fuel line. What i want to know is has any one out there got one or know some one with one in there car an or where to get them from. Finally how much differance the would and or can make. It makes sence that by cooling the fuel down it condenses more their for when it ignights their is a bigger bang. But does any 1 have evidance

[Supra-Jim]

I believe the indy cars used to cool the fuel before filling the cars, not sure if they still do it. But I think it was to get a bee's dick of a % more fuel into the car.

Don't know how it affects performance though.

[devolutio]

extending the question: Do high pressure fuel pumps get hot, and do they transfer much heat into the fuel passing through them?

I imagine when you are making lots of power, and need lots of fuel, you need a powerful fuel pump, which makes lots of heat, which heats the fuel up noticably, which could then use some cooling.

What sort of car with what sort of engine do you have making what sort of power? I doubt a street car would benefit much from having one.

[sirbabblealot]

I have a ra28 celica with a 3s-gte engine puts out about 200rwkw and or 260 Hp at the rear wheels ex targa car. Getting it back into shape to race again tarmac rally, hill climbs and the flog around queensland raceway every few months

[Youngy]

Having cooler fuel is certainly not got to 'reduce' your engine performance, so it can't hurt.

I have seen some set-ups that were literally a small hard shelled wine cooler with a few coils of the fuel line going through it. After all, cool fuel is more dense etc etc

[wilbo666]

I would think that the big long length of metal HP metal fuel line underneath the car (in great airflow) would do a decent job of cooling the fuel should it be heated by the pump.

Cheers
Wilbo

[Grant]

Race and rally cars is one thing, road cars is another. I don't know about you guys but I just wouldn't be comfortable with a fuel cooler in front of the car in case you have a smash. Can you imagine how much fuel would spray out before the fuel cut-off worked? A lot I'd say.

[sirbabblealot]

It all comes down to where it is mounted i wonder if their is any legal requirment and or if they are not aloud or thought about. Me and a mate from work are looking at getting one testing it in different places (mounted in engine bay back of the car) and also on the dyno. I'll keep every 1 posted when we get to it and put the findings up on the forum.

[AEhachiroku]

Hey all

Fast fours or hots fours tested this sometime ago on a worked xr6 turbo. They recorded something like a 3degee increase in the heat. That was from before the pump and after the pump i think. so by the time it gets downs to the injectors that would of dropped but gone back up because of under bonnet temps. So is there really any point to cooling the fuel down unless you can get it to drop like 15degrees????


Cheers
Craig

[Slipper86]

actually the reason (one of) that indy use fuel coolers is because they have such high fuel pressure, because of high revs etc, is because the higher the pressure of fuel the hotter it gets. and you dont want hot fuel.

[Slipper86]

although I did argue the hot fuel point with my mechanics teachers at TAFE but hey they only know what text books tell them. HAHAH

"Hot fuel is better cause it attomises better" they would say.. then I friendly reminded them of weber carbies

[Slipper86]

although I did argue the hot fuel point with my mechanics teachers at TAFE but hey they only know what text books tell them. HAHAH

"Hot fuel is better cause it attomises better" they would say.. then I friendly reminded them of weber carbies.

[MWP]

extending the question: Do high pressure fuel pumps get hot, and do they transfer much heat into the fuel passing through them?

They do.
High pressure pumps use the fuel as a coolant as it passes through.
Hence why running a high-pressure pump with no fuel is bad... they overheat and burn out.

Also, colder fuel isnt useful because its more dense (you can just tune for this), its useful because it cools the inlet air, making it more dense (similar effect to water injection).

[ed]

as ^^^^ he said...

Sport Compact Racing Fuels
Advancing the Science of Motorsports™
Tech Bulletin prepared by Steve Burns, Director-Research & Development

4. COOLING EFFECT: The cooling effect on fuel is related to the heat of vaporization. The higher the heat of vaporization, the better its effect on cooling the intake mixture. This is of some benefit in a four-stroke engine, but can be a big gain in two-stroke engines.

[EVOSTi]

i had a problem with the temp of my fuel, i was running a small surge tank (approx 1 litre) and the return line from the engine went back to the surge tank. so on a hot day the fuel would go through the fuel pump, to the hot engine and back to the surge tank to get pumped again. the fuel pump would get noisy and die. i was thinking about a fuel cooler or a fan for the pump but what i ended up doing was returning the fuel to the main tank first and getting a higher flowing lift pump that outflows the high pressure pump and the problem was solved.
so i dont know about the performance of the engine but the heat of the fuel was affecting the operation of the fuel pump.

[Art Racing]

Sorry, bit late on this. Supra has a fuel cooler, it is plumbed between the pressure regulator at the end of the fuel rail and the top of the surge tank. It is basically just a small oil cooler with smaller AN fittings than normal, and is mounted in front of the radiator next to the engine oil cooler. Theory (and practice) is that there is quite a build up of heat in the fuel as it passes through the fuel rail etc, that isn't so bad for the fuel that is immediately injected, but what about the fuel that isn't? If you plumb it straight back to the surge tank, you could be recirculating it over and over and just heating it up, and the fuel pump etc. The cooler avoids this. I don't know if it is such an issue for sprint races etc, but would definately have been a problem at long races hence why my car has one. And as we are trying to keep it original we have kept it, but again I don't think it will matter in our 6-10 lap races.

John
ART Racing
1983 Group A MA61 Supra

[Grant]

I saw an interesting factory fuel cooler idea the other day on a TVR. They fitted a jacket around the low pressure line of the A/C pipe and passed the fuel around it. I thought it was a neat idea and probably too hard to do.

[river]

Hi,

Remember the episode of Myth Busters where they were trying to cool beer quickly? One of the ideas they used was a copper coil tubing, with dry-ice packed around it. Problem was it froze the beer. However it may not freeze petrol and if the coil tube was in a small insulated box, packed with dry-ice it may be okay for a short race.

Also, you could probably muster up something fairly easily using Peltier devices. It won't get as cold as the dry-ice, but at least it will always be available as soon as the ignition is switched on.

seeyuzz
river

[nick.parker]

Hi,
A few months ago, I drove my car for about 90 minutes on a hot day (36+ degrees). .
I logged my engines lambda over the whole drive. When I went back through the log, I discovered that on average (freeway and stop start driving) the lambda had got about 0.1 leaner from the start of the drive to the finish..i,.e. a real trend!! I think this may have been due to my fuel getting hotter and hotter. My car (4AGZE AW11) has a Walbro 255 pump. After the drive, I noticed fumes coming from the fuel tank area, and when I opened the fuel cap there was a fair bit of pressure released, this hasn't happened since that hot day.
My car 3/4 full of fuel. Actually maybe the positive fuel tank pressure was causing the problem, I am not sure.

Does anyone know the figure for fuel density vs temperature? if its significant I plan to add a fuel temp sensor and a compensation table to my ECU.

Regards, Nick.

[Joshstix]

The Walbro is quite a big pump for a GZE. You're moving the fuel through the hot engine bay a lot of times which is going to raise the temp of the fuel appreciably.

Lets look at the fuel flow you have, the pump is rated at what 255lph? Say it flows 200lph at the average fuel pressure you'll be using, then we're pumping the entire contents of a full AW11 tank through the engine bay once every twelve minutes. I don't know how big GZE injectors are so lets say they're ~350cc, assuming that over a typical drive the injectors average out to run at 50% duty cycle over all then it should take just under an hour to empty the tank. Even at this inflated rate you're still moving the fuel through the engine bay at least 5 times.

The less fuel in the tank the worse the situation gets.

This can be a big problem for a car with such a small engine bay as an AW11.