C5Natie
05-20-2010, 08:01 AM
Just thought I'd share this in case it can help someone.
I have a heads/cam LS6 with a 12:2 compression ratio in my vette. For the last few months Ive been messing with it here and there trying to see how much timing I can put into it without detonation or pinging. Well, Im in CA so 91 pump gas sure doesnt help. My first idea was a methanol and water injection system. I pieced one together with a Snow Perf pump and a Summit RPM window switch. It worked good but on hot days I still noticed some lugging when loading up 4th on the frwy (its an A4), like partial throttle at highway speeds. Now with 100 octane being $7.99 a gal I didnt want to spend $120 on a full tank of gas so I did some research on e85 which I knew was about 105 octane. A few problems arose, first, what was the availability of e85 and, what mods are needed to run e85?
First, CA sucks at e85 availability but luckily for me theres a Chevron with e85 three blocks from my house. Still, I didnt want to be dependant on one gas station with the nearest one being in Beverly Hills 45mi away. So I decided, based on octane calculations, to use a 30% mix of e85 to 91oct:pot_stir:. This would yield me an octane of about 95.4 which is more than enough for my application and the percentage of e85 wouldnt be too high so that I can fill up with all 91 if I had to and the car would only run a bit rich but it wouldnt hurt anything.
Then, what would I need to run e85? NOTHING. If your car is newer than 1988 I wouldnt worry about corrosion problems. Methanol is the alcohol that eats everything up not ethanol, you'll be fine. All i had to do was richen the fuel. Since I have bigger injectors, it took about a 5-7% increase in fuel throughout the fuel curve. The AFR at WOT is now 12.5, right on the money for this percentage of ethanol.
Results, well I havent put it on a dyno but idle feels a lot stronger, it revs up quicker and pulls like a freight train up top :drive:. I have it at 26* of timing right now which is quite a bit for this high of a compression. So far Im very happy but I have yet to drive it more and go to the 1/8mi track next week. So, if youre close to an e85 station and youre a FI or high cr N/A car you should really consider using e85 even if its just as an octane booster. Theres some info on full e85 conversion but almost nothing on partial percentages like myself and on how to tune them. Its a learning process but just experiment till you get the right AFRs and you can add more timing with no detonation problems. E85 is good stuff, safe, clean, creates more torque and cost 40% of race fuel. To get 95.4 octane I use 10.5gal of 91 to 4.5gal of e85. 15gal for a full tank equal $46, cant beat that.
I have a heads/cam LS6 with a 12:2 compression ratio in my vette. For the last few months Ive been messing with it here and there trying to see how much timing I can put into it without detonation or pinging. Well, Im in CA so 91 pump gas sure doesnt help. My first idea was a methanol and water injection system. I pieced one together with a Snow Perf pump and a Summit RPM window switch. It worked good but on hot days I still noticed some lugging when loading up 4th on the frwy (its an A4), like partial throttle at highway speeds. Now with 100 octane being $7.99 a gal I didnt want to spend $120 on a full tank of gas so I did some research on e85 which I knew was about 105 octane. A few problems arose, first, what was the availability of e85 and, what mods are needed to run e85?
First, CA sucks at e85 availability but luckily for me theres a Chevron with e85 three blocks from my house. Still, I didnt want to be dependant on one gas station with the nearest one being in Beverly Hills 45mi away. So I decided, based on octane calculations, to use a 30% mix of e85 to 91oct:pot_stir:. This would yield me an octane of about 95.4 which is more than enough for my application and the percentage of e85 wouldnt be too high so that I can fill up with all 91 if I had to and the car would only run a bit rich but it wouldnt hurt anything.
Then, what would I need to run e85? NOTHING. If your car is newer than 1988 I wouldnt worry about corrosion problems. Methanol is the alcohol that eats everything up not ethanol, you'll be fine. All i had to do was richen the fuel. Since I have bigger injectors, it took about a 5-7% increase in fuel throughout the fuel curve. The AFR at WOT is now 12.5, right on the money for this percentage of ethanol.
Results, well I havent put it on a dyno but idle feels a lot stronger, it revs up quicker and pulls like a freight train up top :drive:. I have it at 26* of timing right now which is quite a bit for this high of a compression. So far Im very happy but I have yet to drive it more and go to the 1/8mi track next week. So, if youre close to an e85 station and youre a FI or high cr N/A car you should really consider using e85 even if its just as an octane booster. Theres some info on full e85 conversion but almost nothing on partial percentages like myself and on how to tune them. Its a learning process but just experiment till you get the right AFRs and you can add more timing with no detonation problems. E85 is good stuff, safe, clean, creates more torque and cost 40% of race fuel. To get 95.4 octane I use 10.5gal of 91 to 4.5gal of e85. 15gal for a full tank equal $46, cant beat that.