Freestyle What race fuel is everyone using?

Did a quick search on this and i haven't found much in the recent years since billet cylinders have become more common in skis. Im starting to see the light at the end of the tunnel for my flatwater build and started looking at what fuel i want to get on order with my distro. With so many options out there now I'd like to have some input from people that have played with fuels (higher OCT, non oxygenated vs oxygenated vs a mix of both. The kicker here is that the lake i ride at mostly is right around 3600ft above sealevel. Me and the motor builder had a chat about this and figured that if he cut the domes for "220"psi at Sealevel then that should put me around "190"psi here with the elevation. I still want to run race fuel just for the peace of mind of keeping my new superbore stock stroke motor happy as possible. Also prop choice had the elevation in mind too for what it matters.

I raced dirtbikes for a good chunk of my life and always ran oxygenated fuels to get the most out of the motors (wether it was 2t or 4t). On 2 strokes if we knew we were going to a track at much higher elevation we would switch to a higher oxygen fuel like MRX02 to help get some oxygen and power back and keep jetting changes to a minimum. Knowing that this ski will probably burn 5x the fuel a 250 2 stroke dirtbike will, I don't think ill be wanting to spend $150+ on 5 gal pails of MRX weekly.

Looking through the VP fuel charts and from first hand experience im thinking something like a 50/50 mix of VPR or U4.4 cut with VP110 or C12 at my lake to get some oxygen. Then if i ever go to havasu or somewhere else closer to sea level ill try and run a non Oxygenated fuel like VP110 or C12 straight to try and keep the power and jetting close to the same? Maybe my mind is just swirling with these ideas but i figured it's a good topic to get some insight on from people with more experience with fuel testing. Im also not against running VPR, U4.4, (or something similar lower priced with oxygenation) straight at my lake if it will help a good bunch with the power.

I've seen some pro 1200 guys running MS109 and a few guys running straight C12 so i just would like to hear some first hand experiences from people that have done some testing with this!
 
I’m running Sunoco 110 leaded 4:1 with 91 in my 900rr at 4000ft elevation. Burned probably almost a drum of it already with no problems. Will tear down at end of season and report any findings. I think race gas is a must if you are always riding at high elevations and don’t want to lose as much power.
 

Mike W

Infidel
Site Supporter
100LL mixed 50/50 with 89 octane non ethanol. Mixed 50:1 with Amsoil Interceptor.
 
You might be able to get Sunoco 260 GT at the pump. I have one about 15 miles from me. 260 GT is unleaded, oxygenated 100 octane and I've paid somewhere around $7-9 a gallon when I have purchased it. Avgas 100LL is a good option if you have a small airport near you that allows self service. Price is right where bored&stroked said, it's around $4.70 near me. You can check prices here.
 
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i like using leaded fuel as its great for detonation resistance and also provides extra lubrication especially for 2 stroke engines. ive used 100LL many times with no issues as well as certain marathon gas stations would sell unleaded 100 at the pump. my x2 with a built 750 needs minimum 96 octane so ive been using "predator" brand leaded 110 with 93 to make a 98-99 octane blend. ill mix 1.5g of 110 with 3.5g of 93
 

Big Kahuna

Administrator
i like using leaded fuel as its great for detonation resistance and also provides extra lubrication especially for 2 stroke engines. ive used 100LL many times with no issues as well as certain marathon gas stations would sell unleaded 100 at the pump. my x2 with a built 750 needs minimum 96 octane so ive been using "predator" brand leaded 110 with 93 to make a 98-99 octane blend. ill mix 1.5g of 110 with 3.5g of 93
Extra Lubrication?????????????????
 
Here is some related reading. Some oxygenates are corrosive so just be aware. Ethanol is the most common oxygenate too.
https://thumpertalk.com/forums/topic/1189147-oxygenated-fuel-experiences/
http://greenhulk.net/forums/showthread.php?t=17626

I don't have experience running 260 GT in a ski but I have a tune for it on one of my turbo cars. Mainly mentioned it due to availability and since you said you were looking for an oxygenated fuel.
Those links have some good info thanks for those. I don't have a reliable sunoco dealer within 100 miles or so. VP and Renegade are much easier for me to get over here
 

Big Kahuna

Administrator
We not talking about 4 Strokes. I am curious about the "Lubricating Qualities" I searched, could not really find anything.
 
In a twostroke, lead is mildly abrasive, its not an issue in high performance applications . Lead is the easiest way to get the octane up.
 
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