Fuel useage

[Vulnavia]

How much fuel is needed for a 13 lap national at Road America. Time to order a fuel cell.

Will

[clint]

a 6 gallon with a collector tank in the middle of it. Glad to see youre getting close!

[Vulnavia]

Thanks Clint,
Could you explain about the collector tank. The reason you need one and its size, material and fittings or ports.

Will

[rickb99]

a 6 gallon with a collector tank in the middle of it. Glad to see youre getting close!

Geezz, that's as much as a Formula Continental would use!

[Jnovak]

Actually they use about 4 gal or less. The reason for the collector is that the engines are fuel injected and ANY loss of fuel pressure caused by surging in the cell causes the engine to hesitate.

We make ours out of aluminum and use the fuel safe surge valves. This works great and our cars never have a fuel pressure problem.

Fuel Safe makes a nice production 6 gallon fuel cell for a reasonable price. In fact we just put a new one of these in our Runoffs winning car.

[tedsimmons2]

I used 3.0 gallons at the October 5th Summit Point race that consisted of 16 race laps, one out lap, and one cool down lap. !8 laps at 2.0 miles per lap = 36 miles and used 3.0 gallons, ~ 12 mpg. Engine is GSXR 600, YMMV. My converted Novakar car has a 5.0 gallon fuel cell and I'm planning to do the entire ARRC race distance without refueling.

[clint]

The biggest reason for major differences in fuel usage is the way one person drives as opposed to another. Its pretty much like asking several people that drive the same vehicle what kind of fuel mileage they see. One will say 40mpg, another 50mpg, the last person may say 60mpg. I suspect the first person stands on it at every red light they come to and goes as fast as the car will allow on every paved and non paved road they come to. They second person may roll into it at red lights and only stand on it in the straights. The last person may just be out on a sunday drive enjoying the view. It all depends on who's driving that particular car . I can tell you from experience that a 5 gallon cell is almost enough, but just not enough. The bottom of the cells in these cars have a big foot print. As the gas goes from one side to the other the pickup will eventually suck air even with a gallon and a half in it. In order to minimize this we put a scavenge tank on the bottom of the cell to collect as much fuel as possible when it goes from side to side along with a external surge tank. Some may find that a 4 gallon cell works fine, some may find that it wont. The size of tank you think you need all depends on how hard you think you will drive the car everywhere on the track.

[jim murphy]

A related issue is whether you use street 93 octane gas or not. Since it has up to 10% ethanol just ensure that you buy a fuel cell that tolerates alcohol. I suspect that the fuel cell makers now may make their cells handle both gas and alcohol but I am not sure so ASK the fuel cell vendor about this BEFORE you buy a fuel cell. Just ask George Bugg what happens when you run 93 octane pump gas in a fuel cell that does not handle alcohol. BTW, 93 octane street gas has been passing the fuel check at the tracks. They say that anything OVER 10% will bust you. This is a HUGE savings on fuel each weekend.

Jim

[Jnovak]

George's fuel cell was between 8 and 9 years old when it failed. The failur may simply have been old age.

[jim murphy]

Will,
I just noticed that you have been posting car build questions since 2012. When will we see you on track? We would like to see photos of your car as you continue to build it.

Jim

[mmi16]

All the fuel cells I have had fail have been between 8 & 10 years old.