Okay, stupid question alert: if I'm running 91 pump fuel, how many gallons of 101 octane unleaded fuel would I need to add to each tank to make it equal94 or 95 octane? I've asked a few local people, but I can't seem to get a clear answer. I've been told when mixing in leaded fuel, pretty much one gallon of 90 octane and one gallon of 110 octane would make two gallons of 100 octane, but with UNleaded fuel, isn't that cut and dried. When I fill up, I want my octane to be consistant with each tank, not just guessing. Help

-Chris

 

I think for every four gallons of race fuel if you use seven gallons of 91 then you should be at 94.5 octane. I am not a 100% sure on this, but I think it is the way you figure it out.
My recommendation is to tune it for 91 and when you want to take it to the track or run your high setting then you put in some race fuel, and it does not matter what the octane it. Just, what I am doing. I have it tuned for everyday driving at 91 and when I do anything different I put in race fuel.

 

Yes but I want to tune for 93

I want 600whp

 

this is simple,

the Z's gas tank is a 20 gallon tank

16x91 octane = 1456
4x101 octane = 404

1456+404 = 1860

1860/20 gallons = 93 octane



so you're looking at a 4/1 ratio with 91 and 101 octane

 

^^ I second sentry's calculations, don't know why unleaded gas would have different rules for mixing.

 

Then the above calc is right if you want 93 octane.

If you want 94 then you do 6 gallons of race fuel and 14 gallons of 91.

If you want 95 then you do 8 gallons of race fuel and 12 gallons of 91.

Basically every extra gallon of race fuel gives you half an octane in a full tank. That should let you tune it to whatever octane you want, even half increments.

 

For exact proportions, see the attached blend chart from 76.

The chart is for 91 octane mixed with 100 octane. In that case, it shows 2 gallons of 91 for every gallon of 100 to get 94 octane.

 

Just checked Sentry's math using the Alligation method - he's right: 8 parts 91 octane to 2 parts 101 octane to equal 93 octane. For 94 octane, I get 7 parts 91 and 3 parts 101... close to the blend chart anyways

 

Sentry, everybody, thanks! That makes perfect sense. I'm glad someone around here went to collage.

 

collage, lol

 

lol

 

can you guys do my homework for me too..

 

Or at least 6th grade....

 

Thanks for the input smartass!!! The college remark was a joke!

If you'll re-read my first post, you'll see that I was also told (by a guy who sells race gas wholesale) that it's not just as easy as doing the simple math, and that you can't just throw in those ratios and have it be exactly the correct octane.

 

i knew you were joking, thats why i brought it to light, lol.

 

Yea well RiceZone needs to apologize quick before my feelings get hurt

Jk ken, I love ya

 

http://www.motorsportsracingfuels.co...alculator.html

this will help you out

 

Cool site, thanks.

 

I knew he was joking too. Gezzzz, lighten up.

 

I should have used a . My fault. I threw it in there fast and didn't think.