I am at the track, car is tuned on VP C85 and the car went several rounds today and we are down on fuel. There is no C85 available and a buddy has some E98 in the next pit. How much is it going to affect the tune if I put a few gallons of E98 in?

 

There is still probably 3-4 gallons of C85 in the tank now to mix with.

 

I guess I should mention it's an all motor car.

 

I wouldn't do it

 

I wouldn't do it

 

How many more passes do you plan on making? I'm also using c85 and 10 gallons has lasted me a dyno session and 14 passes so far and I still have just under half a tank according to my fuel gauge.

I'm sure 3-4 gallons will get you 10+ passes if that's what you're concerned about.

 

thats a big difference, you would want to add probably 5% fuel atleast to be safe for the first run when last resorting to something like that. Log it, Fix it.

 

its math.. one c85 is 85 parts ethanol and 15 parts some type of fuel and additives, e98 is 98 parts ethonal 2 parts some other crap. if u want to make home brew e85 then mix 85 parts ethanol and 15 parts 93 or some type of race gas. or for 5ish gallons i think its 4.5 e98 and .8 fuel.. im converting off litres sorry. its 17 litres e and 3 litres fuel. i make my own e all the time cause we dont get it here in canada. as long as your not off more then like 5 points ethanol either way you should be fine.

 

that is why I love my Zeitronix ethanol content analyzer (ECA)... plus I carry little bottles of pure ethanol with me to match what I am tuned with.

 

We actually just cut down the E98 fuel with 87 Octane to make it E85. Added 13% 87 Octane to the E98 and it worked great, raced all day and the car even went a bit faster.