Race gas... Methanol... Avgas even??

[rowsto]

Hi all, im looking at converting to high compression on my dasa and running race gas, although price and availablility is far from perfect. Has anyone looked at mixing say 25% methanol with 98 ocatane fuel? My sums put this mix at about 103 octane. Is this actually an option or should i just fork out the high cost of 105 octane race gas?

just some numbers in case anyone was interested (australia)
98 octane - $1.40 / L
Methanol - $363 200L drum
105 octane gas - $850 200L drum
VP race fuel MS109 (the blend Lee Stone uses) $215 for 20L yes thats not a typo 20 Litres

 

[Nsmith212]

Methanol probably won't mix well with the rubber in your carbs and stuff. I believe you'd need Teflon parts. Never used it personally. It burns twice as fast so your jetting would change significantly. AV gas is a pretty good option at 5.25 ish a gallon for like 100LL. -low lead 100 oct. 100 octane should be plenty for freestyle type riding. Long wot runs would be iffy. Just my 2 cents.


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[rowsto]

It's a flat water only boat 1100 dasa. You mean run straight avgas? Would 98 fuel plus some decent octane booster suffice?

 

[Nsmith212]

I'm not sure I believe it but I've been told from engine builders your better off running sand than octane booster lol but I haven't seen any damage from it


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[Nsmith212]

Vp makes a fuel called import, and it's a high rpm fuel that's rated over 120 octane. Maybe you can mix it with a low enough percent to make it cost effect?


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[Harbor]

Somebody else tried the octane booster in another thread and it didn't go well at all, don't do it

 

[rowsto]

So that's a no to the octane booster and a no to the methanol mix, I'll check the prices of the 120 octane vp although it's probably going to be 250-300 a 20l drum. So tell me about avgas, what's the difference between 100ll avgas (100 octane) and normal premium unleaded. Apart from the slight octane difference is there any other pros and cons?

 

[Nsmith212]

Yeah I hear it doesn't go bad very quick so it's good for winterizing. Over than that not really. It's low lead so not really any increase in lubrication. Not oxygenated so no huge power gains. But it does burn faster I believe, so tune a little richer and you should get a little more power.


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[Nsmith212]

I'm probably not the best to be giving you info but there are a thousand answers to your original question. Just giving you some info to chew around on


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[rowsto]

I'm not really chasing power gains from the fuel itself, more so the gains from the high compression and advanced curve. I just want a fuel that will compliment the setup and be "reliable". Maybe avgas is the go

 

[jo5hi3]

Check out vpr. Its a 105 oct fuel with like 6% oxygen. You will get added power from the oxygen. Vpr also has lead in it. Its a little cheaper than ms109.

 

[Waveblaster785]

Location probably kills you, but to pay that much for MS 109 seems absurd. You're buying the can.

I purchase 110 at the pump for $8.00 per gallon where I am. I also purchased a drum for the same per gallon price.

It's about 50% more expensive in the 5 gallon cans from my experience.


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[Schmidty721]

Fuel threads always get so much info spit around from so many ppl, much of it being incorrect.

First off, your 98 premium is on a different rating scale than our premium in the US. US uses R+M/2 to average the octane ratings giving you pump octane. Your 98 is based on Research octane numbers only. Ie, your 98 is = to our 91-93 premium. 100LL AvGas would be more resistant to detention than just 2 octane points on your pump gas.

Methanol isn't worth the headache. Cross that one off.

Octane booster is a marketing scam. Don't use that crap.

Race fuel comes is so many different variations it'll make your head spin. I would discuss your options for fuel availability with your engine builder and come up with a fuel/engine package that will work well and not drain the bank account.

 

[rowsto]

Aw man just when I thought I was getting my head around it haha. Would fuel stations have a msds sheet or information sheet on their fuels listing the values that I could get if I asked?

 

[Harbor]

Look at your pump, ours are marked

 

[rowsto]

Yeah premium says either 95 or 98, but Schmidty just said that's not an accurate measurement?

 

[Lumpy]

Do a Google search. It's the same garbage, the octane numbers posted at the pump are just calculated differently.

 

[Harbor]

Sorry, I ment for you too look at the pump, it will most likely tell you the method used to calculate the min octane. If you look at the above pic it has the formula on the labal above the 91. Reading that info at your pump will help you verify the octane. In the EU the 98 is our US 93, this is what he's talking about

 

[Schmidty721]

Yeah premium says either 95 or 98, but Schmidty just said that's not an accurate measurement?

It's accurate, just not the same calculation used in the US. Typically "R" octane numbers are about 10-12 points higher than "M". In your fuel they are only using the research " R" number on the pumps. Here they average both.
(98 R + 86M)/2 = 92

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[jetpilot36]

at 200psi compression AV gas will be perfect. That's going to be your best option. Well...your best option economically.