Some more Info I have been supplied by one of the guys who runs in one our our classes.
In September/October last year we did some dyno and track testing with E85. The following is what we discovered.
1) Power increase; in our situation a power gain of around 5% was achieved over avgas. For other cars where the ignition advance is more limited by detonation a greater power increase would be achievable.
2) Earlier boost pressure. However the down side of this is that it aggravates any boost creep problems. Also for the same boost control settings there was an increase in boost (so the settings had to be decreased to achieve the same boost level)
3) Lower engine temperatures. On track testing showed the engine temps were brought right down to the thermostats temp and was almost operating too cold. We would look at either changing the low temp competition thermostat to a standard higher temp item or look at blocking of some of the air to the radiator if we were to continue with E85.
4) A drop in exhaust gas temperature.
5) In our situation the optimum air/fuel ratios required around 50% more fuel with E85 for full power. For part throttle around 30-40% more fuel was required. This means that the injectors, fuel pump and fuel system had to cope with 50% more fuel delivery. On track fuel usage increased by around 30% (as the engine is not operating at full power 100% of the time).
6) Greater ignition system demand. If your current ignition system is boarder line with petrol it may have to be upgraded.
7) There were some other tuning considerations including cold starting.
Build up of fuel in the sump and accumulation of fuel in the oil breather catch tank with E85.
E85 is less volatile than petrol meaning that it takes a higher temperature to make it evaporate. More fuel enters the sump with blowby gases due to the fact that more is used and also under cold start and while the engine is warming up. The engine and engine oil needs to be above 78C to get the E85 to boil of and leave the sump at a reasonable rate (this is compounded by the fact that the fuel makes the engine run cooler). Also once it does leave the sump it condenses in the cooler catch can and builds up in the can.
9) It burns with a completely invisible flame.
10) Effect on fuel system materials. Counter to some info out there it does not attack aluminum. It does go wild on Teflon paste thread sealers ˆ it cleans this out of any treads & mixes with the fuel, and then blocks any strainers and filters (normal thread tape is ok to use). Being alcohol it is a very effective cleaner ˆ this causes problems in that any trash and gunk is cleaned out of the fuel system then mixing with the fuel which then blocks strainers and filters. In our situation it blocked the strainers for the intakes of the fuel pumps causing them to cavitate and drop fuel delivery. This happened once on the dyno and twice during track running (this was in addition to the incident with the thread sealer).
11) It attracts moisture ˆ extra consideration is needed for the engines winter storage and the fuels shelf life.
12) Cost per litre. The brand that we were using cost $3.06 (incl gst) per litre when purchased in 20L tins and $2.94 (incl gst) when purchased in 200L drums. OSCA have priced E85 from Gull at around $1.60 /L (not sure if this includes gst) but they have to buy 20 x 200L drums each purchase to get this price. GTRNZ are offering 200L drums at $2.36/L (not sure if this includes gst). None of these prices includes freight. The sharpest freight prices we could find were $83 (incl gst) to get a single 200L drum down from the north island and $60 (incl gst) to get 4 x 20L tins down. So add around 40C/L to get a 200L down.
The OSCA price was including GST and the freight price is less than $50.00 per drum ($0.25 per litre)into ChCh.
13) Availability at short notice?
