Tahoe Shark

As soon as George get the reliability sorted out he will be able to use his massive HP to turn in some really good speeds. Everyone at the event is always pulling for George to crack the 200 mph barrier including us. It is frustrating we know, but he will do it, it is just a matter of time.

jorj7

Colin,

OK, thanks. I'm on my way to Tahoe to retrieve my race tires and wheels from
Tim, so I'll be off line for about 8 hours.

Tahoe Shark

See you at 4pm

IcemanG17

George
Hot fuel does seem like a likely culprit.....maybe add some fuel coolers into the mix.....couldn't hurt?

stuartph

George

Thanks for the photos

Did you go with this intake to avoid sucking in hot air plus gain more power, and has it given more power ?

jorj7

Stuart,

Yes, I did it to do both, avoid hot air and gain more power. I haven't done any
high boost dyno runs yet, so I don't know if I got more power, but I have seen
the intake temps go down significantly.

WallyP

George,

I think that my first attempt at a fix would be a fuel cooler can on the return line - probably in the rear near the fuel cell.

A few pounds of plain ice and water might last long enough to prevent any problems.

Lizard928

Talking with George about this via PMs, but part of the problem is the location of the hard fuel lines. This is where they pickup a ton of heat.

What I will be doing with my car to resolve this issue is to run new hard pipes from the tank up and into the passenger side frame rail. This shields it from the exhaust entirely. Then exit the hard pipes just after the bumper shock. Running a small rad style cooler in front of the rad. Or preferably in the fender. It would be best to do this for both Supply and Return. Then have the hard pipes enter from the front of the engine (shielding the pipe inside the engine bay). For the return I would punch it straight through into the heater box area and then run it in that area and back into the fenderwell along the top of the fender for the return cooler up front again and back into the frame rail.

It also would be a good idea for a car like Georges to do a coil of aluminum pipe in a vented container that he could fill with dry ice just before the event to ensure that his fuel remains cold for the entire race.

The temps that he is seeing (nearly 50 deg C) can result in a dramatic leaning of the AFR. One should also consider fully insulating the fuel rails to prevent heat transfer from the engine into them too.

IcemanG17

http://www.designengineering.com/pro...asp?m=sp&pid=3

What about a fuel cooler like this....fed from a tank in the cockpit.....you can adjust the amount of cooling based on temp-load etc....this might work nicely....on an ORR car where weight itsn't as important it should work good....might be too heavy for a track car (not sure)...but maybe not?

It appears to have a trigger switch...say WOT that turns it on..... add one fuel cooler just before the pressure regulator under the hood and that should guarantee cool fuel....I wonder how long a 5 or 10lb can would last at WOT? If the only fuel coolers are used its a closed system so it should last a while?

BC

It seems like constantly spiking the fuel temp into low figures would be just as bad - the tuning required would be monstrous I think. A constant temperature CONTROL of the fuel I think is idea. Coolers that use ambient air would be best, I suppose, except for very hot ambient temps. Then some sort of dual loop system that uses its own heat exchanger. I don't think that system would be too heavy.

Lizard928

I disagree,

The reason is that the cold fuel will cool the charge resulting in denser air. Sure if you go too cold then yes you could run into trouble. But using a canister filled with dry ice to cool the charge and fill the canister right before your run I doubt that it would cause the car to go excessively rich. The tank will still remain hotter due to the exhaust and other heat passing under the car.

The fuel cooling the charge is part of the reason that moving the injectors further away from the valves results in more power.

BC

No, I agree that the cold fuel is denser, thereby creating denser air (part of the reason I am 100% into E85). But How do you tune for the temp changes as it artificially surges and spikes? It seems like super cooling it would cause more problems.

I have planned similar controls on the fuel return and supply so it does not get abnormally heated. Ethanol has some eccentricities in this regard.

Lizard928

The cooler fuel will result in a slightly richer state than ambient temps which is ok for a boosted car that is sharktuned properly. But when it gets close to 50 deg like George is seeing it becomes very thin. I had the same problem with my 86 engined car and it was just that the fuel was getting to hot. I was able to mostly correct for it with the MS without adding a fuel temp sensor. But for my next car I will be adding a fuel temp sensor right around the FPR and adapting it to the brain to adjust the maps for fuel temps too.

Tahoe Shark

Take into consideration where we race. I haven't checked but places like Ely, Wendover, Arnold and other locations probably will not have access to dry ice. That would mean picking up the ice on a Wed transporting it and hoping it would last until Sunday when we race. I would think a cooler based off of ambient would be the better choice if it was available.

SwayBar

Sorry George to hear about your problem...

Also, I had no idea a problem like this existed, so in that regard, excellent thread.