E85 has some great performance benefits and a lot of potential. Since the pump blend is formulated to be used on computer-controlled "Flex-Fuel" vehicles, there is a lot of room for variances in the fuel's composition that carburetors can't account for on the fly. In the vast majority of cases, the mixture ranges in a narrow band from 83-87 percent, but there is no hard guarantee. With an easy-to-use tester, or a reliable fuel supplier, this problem can be avoided. With the price of around $2 a gallon, E85's tolerance to high compression and advanced timing can't be beat for the money.
|Gas versus E85 Metering |
|Here’s a basic comparison on what the metering changes are from gasoline to E85 in a 750-cfm carburetor. Specifications courtesy of Barry Grant. |
|PART: ||GAS: ||E85: |
|Main jets ||76/83 ||85/93 |
|Idle air bleeds ||70 ||63 |
|High-speed air bleed ||39 ||29 |
|Booster legs ||160 ||169 |
|Squirter ||31 ||35 |
|Needle/seat ||110 ||130 |
|Idle feed restrictor ||39 ||36 |
Where Can I Get E85?
The biggest hurdle in a beneficial conversion is access to the fuel. In California and other western states, the juice is nearly impossible to find. On the other hand, states like Minnesota have it off every freeway exit. Check the map showing the concentration of pumps in the Midwest, and the absence everywhere else. The price for E85 has been consistently reported to be slightly less than the lowest grade gasoline available, putting the average around $2 a gallon. There are over 2,000 E85 retail filling stations out there, and the numbers are growing, but not as fast as we'd like. In order, Minnesota, Illinois, and Wisconsin have the highest number of E85 stations. If you don't live in the grain-belt, you will have to travel to get the fuel, and until it becomes more readily available, you may hold off on the conversion for a street car.
In a race application, you aren't bound by the convenience factor, since most race cars don't have to travel very far under their own power. This is where Rockett Brand Racing Fuels comes in. They produce an E85 fuel that is guaranteed to be 85 percent ethanol, unlike the pump stuff. This consistency is very important to drag racers who need their cars to run consistently. Rockett has the same government requirement to de-nature the alcohol used in the fuel, but they use a special additive that actually burns well. Instead of throwing whatever gasoline they can find into the mix, they've created a special blend of chemicals used for building race gas to work optimally with the ethanol. Rockett knows the fuel needs additives that the government doesn't require. Alcohol has poor lubrication properties, so they've added lubricants in addition to corrosion inhibitors. This special attention to the fuel's contents gives it a 112-octane rating, far more than the government's estimated 105-octane pump E85. To find out what E85 fueling stations might be near you, log onto the National Ethanol Vehicle Coalitions' website: www.e85refueling.com.
"There are over 2,000 E85 retail filling stations out there, and the numbers are growing..."