Race Fuel

[sandy blonde]

I've been running 91 octane in my 86 trx 250r for the last three years and decided to try giving my quad an octane boost. So I mixed 1 gallon of F&L (111 octane) in with 3 gallons of 91 (and HP2). But if anything I noticed a lack of performance, especially in power band. What's your experience with changes in octane? Should I adjust the fuel/air ratio? I really want more power without modifying my quad, so I thought that race fuel would be the way to go.

[Suz_Madness]

hmm well i thought race fuel was only needed for certain application's after modifying but im not too sure, one question though why dont you wanna modify your quad if you dont mind me asking?

[climb any hill]

You need to build the cylinder to run more compression to accept those levels of octane.

Check out Chemical Forum, there's a good read in there!

[sandy blonde]

I got the top end done this summer, there's probably 11 hours on it. There's still a lot of meat left in the cylinder b/c this was the first time it was bored and now has a pro-x piston. I don't want to do more to it til this coming summer (out of funds). Once the time comes, I'll probably be asking what to do to get more hp without going totally nuts

[2002shee]

You're not going to gain much by running race fuel without the appropriate mods. If you really have to use it I suggest AV 100ll fuel, it's a lot cheaper then race fuel. Otherwise stick with what you're using if it's working for you.

[climb any hill]

You can have the cylinder ported & head milled under $500.
Do you ride elsewhere besides Glamis?

[sandy blonde]

Gordon's Well. That's where I'm headed tomorrow morning I want to hit Pismo this summer. How's Dumont?

[climb any hill]

Ok.. I am now jealous!!
Glamis is way bigger over Dumont but Dumont is way taller... way steeper.
Only Dumont has the Super Bowl, you gotta try it! Here's my Dumont pics
http://forums.everythingduners.com/showthread.php?t=116

And we ride Pismo every summer, you're welcome to come ride with us anytime

[1upfront]

Originally Posted by sandy blonde

I've been running 91 octane in my 86 trx 250r for the last three years and decided to try giving my quad an octane boost. So I mixed 1 gallon of F&L (111 octane) in with 3 gallons of 91 (and HP2). But if anything I noticed a lack of performance, especially in power band. What's your experience with changes in octane? Should I adjust the fuel/air ratio? I really want more power without modifying my quad, so I thought that race fuel would be the way to go.

Racing gas is a richer fuel than pump gas therefore you need less fuel per air for it to burn properly. I switched my stock 250r over to 110 and had to drop a few jet sizes to get it dialed back in.

[stk563]

Race fuel is a useless thing to use on a bike that has no head milling or cylinder re chamfering the compression of your bike is no where near high enough to need race fuel. All this is going to do is cause ur bike to run like crap anytime u hit the powerband as it will also fry the piston faster than anything. The bike you dont wanna modify well best way to get more power is pay someone to port your cylinder it will give you more power without spending alot of money.