codrus wrote:
Anyone used one of those fuel tank/pump things that goes in the bed of a pickup? I think they're generally used for hauling diesel for construction equipment, but is it reasonable to use one for other fuels? I've occasionally thought about running E85 in my turbo Miata, but the number of stations selling it around here are really limited, and you can't get it at the track at all. The in-bed tank seems like it might be a good choice for that.
Only used them to haul diesel, but the worked great for that. Probably the only time I've really been comfortable hauling fuel. They do make ones approved for gas.
z31maniac wrote:
JohnyHachi6 wrote:
In reply to codrus:
Keep in mind that a car tuned to run on E85 uses fuel ~70% more quickly than gasoline. I'm a big fan of E85, but it really limits your range and the practicality of the vehicle if you use it for anything other than short drives or sprint races.
70% more?
Care to back that up with any info? Everything I've read puts it between 30-40% more.
And as I mentioned in the OP, it will be strictly a track car, so I'm not concerned about range.
Yeah, somewhere in that ballpark of 70% depending on the engine setup.
To run the numbers for you (I'm going to use pure ethanol vs gasoline, because E85 data is less consistent, but the numbers are nearly the same):
Fuel content in charge for stoichiometric combustion:
- Gasoline charge = 6.8% fuel
- Ethanol charge = 11.1% fuel
11.1/6.8 = 1.63
That's 63% more fuel to run ethanol vs gasoline and this is at stoich under ideal conditions. (Given you will need just a little less than his since E85 is only 85% ethanol.) In reality though, you're going to tune for power, meaning a richer mixture, and that results in even higher fuel consumption for E85 vs gasoline because E85 combustion can support richer mixtures.
For a sanity check, you can read through the December 2012 GRM issue that has an article about tuning with various fuels. They found that they needed (wait for it...) 63% more fuel to get peak power on E85 vs gasoline.
Also, I would say that as much as I love E85 for applications requiring cheap, high octane, there is little reason to run it unless you have forced induction or a silly high compression ratio engine. The cost of bigger fuel injectors, pump and engine management just doesn't justify the maybe 5-10% hp gains that you might expect to see with a stock engine.
Also, worth mentioning that this comparison is between two essentially identical engines where one is running ethanol and one gasoline. So, the results tell you, "given the same amount of air ingested by the engine, this is how much more fuel you need for ethanol" - this is the right comparison if you're considering switch an engine to ethanol from gas.
This is a different question, however, from "given two engines that make the same power, how much more fuel does the ethanol engine use?" In that case, you're probably looking at closer to 40% more fuel for ethanol, but it's not a realistic question because a well-tune ethanol engine will make somewhat more power.
We bought our fuel in 55 gallon drums and put the drum in the back of the truck strapped in good. For pumping I had a little stand with a cheap Holley pump, a bike battery, and a length of braided line that reached the bottom of the barrel, and had a fitting to fit our fuel cell incase we needed to empty it. I'm not sure of the exact difference in mileage with alcohol but the few alcohol circle track cars I've seen had large cells.
With Miatas, it's 30-40% in practice.
edited because should have read the WHOLE thread first
codrus wrote:
Anyone used one of those fuel tank/pump things that goes in the bed of a pickup? I think they're generally used for hauling diesel for construction equipment, but is it reasonable to use one for other fuels? I've occasionally thought about running E85 in my turbo Miata, but the number of stations selling it around here are really limited, and you can't get it at the track at all. The in-bed tank seems like it might be a good choice for that.
Somewhat, we use a Northern Tool 10 pumps per gallon with 55 gallon drums for our races. Never had a problem with the track, and never got questioned by the authorities, but I am pretty sure that 55 is fine...165 gallons? ehhh..
The only time it got sketchy was when we filled 3x 55 gallon drums for the 24 hour at VIR....
I had two of these when I ran a jet ski rental company.
Holds 25 gal. Easy to move around.
It would probably swell up like crazy with ethanol.
