VP race fuel question

[overkill131313]

the new sled is running 15 to 1 compression ratio.....was going to run av gas (100LL) but it has gone up from $1.43 last year to $1.70 plus......I run it straight in the turbo tank but was wondering what the cost of VP is a liter? and what do I need to make 100 octane???? C12, C14, what is everyone running? what is a good oil mixture to run so I dont foul plugs? should I get those EV plugs?

 

[pipes]

the new sled is running 15 to 1 compression ratio.....was going to run av gas (100LL) but it has gone up from $1.43 last year to $1.70 plus......I run it straight in the turbo tank but was wondering what the cost of VP is a liter? and what do I need to make 100 octane???? C12, C14, what is everyone running? what is a good oil mixture to run so I dont foul plugs? should I get those EV plugs?

$1.70+ still about half the price of VP

 

[Rhodesie]

the price of vp will make you sheet yourself!

 

[overkill131313]

but if I only need to mix it 50-50.....so VP is about $3.50 liter......just trying to work out some figures like every time I go to airport it cost me $20......but I can get VP in town, which saves me $20...... and if I mix it 50-50, it might be the same or more......I dont know!

 

[ryan#1]

I run about 60/40 (91/C12 and no problems with it at 14:1. When i run out of VP I may switch to straight Av as the cost is getting up there for race gas. Why don't you just fill a barrel at the airport and save yourself a bunch of trips.

 

[jbb]

its 4 bucks a liter gary. and you dont need 50/50 unless your running big boost. at 15lbs i run 75/25 or 50/50 with avgas.

 

[P_ZIZZ]

VP in my books is way over priced I just bought a barrel of AFD track tech 111 for 548 bucks for me to get VP 111 it was around 650. And if you already had a barrel you get can buy track tech by the litre which was a bit cheaper ( 40$). They were great to deal with and even had a guy stay late so I could pick it up! I looked into running av gas as well but when I asked linderman he told me at elevation I can run 10psi boost without too much of a worry but any more than that I should be running 111. Just another option

 

[fatguy1]

I'm by no means an expert in this field, but I have been looking into this also.

I'm not sure if motor octane is what a person should compare or some other octane rating, however:
VP 110 has a motor octane of 107
C12 has a motor octane of 108
C14 has a motor octane of 114
LL 100 has a motor octane of 102 (I'm told by my supplier that 102 is the min. that it can be, the last batch I bought was 104 from him)

If getting to the airport is costly maybe the cheaper VP110 will work for you, for me it's waaaaay cheaper to stick with LL100.

 

[moyiesledhead]

VP has the goofiest numbering system I've ever seen!

 

[imdoo'n]

for your mix ratio's modman had a fel calculater posted a while ago.. ya put in yer high test octane, then yer low test octane and what mix octane ya want to get, gives ya the ratio's.

that modman is like one friggin genious i tell ya.

 

[f650]

just bought some at AFD FUELS IN EDMONTON 20 liter pail 54 BUCKS if i bring in my own jugs for every 3 JUGS i buy
i would get one free that the savings with your own jugs and thats 111

 

[Modman]

I'm by no means an expert in this field, but I have been looking into this also.

I'm not sure if motor octane is what a person should compare or some other octane rating, however:
VP 110 has a motor octane of 107
C12 has a motor octane of 108
C14 has a motor octane of 114
LL 100 has a motor octane of 102 (I'm told by my supplier that 102 is the min. that it can be, the last batch I bought was 104 from him)

If getting to the airport is costly maybe the cheaper VP110 will work for you, for me it's waaaaay cheaper to stick with LL100.

Yes, you are comparing it right. You want to compare the Motor Octane Number (MON), not the research octance (RON). Av and race fuels are not the same thing, but they work in the same applications, only difference is quality. Race gas is blended much more consistent than av and often times has things like different specific gravitys and vapourization pressures. I know lots of people will think I'm "crazy" for saying that av and race fuels are different, some people are stuck believing that av and race fuel come from the same tank at the refinery - they don't. Honestly. Most applications of the internal combustion engine will tolerate each fuel, but race gas is far more consistent in the product you buy, which is why you pay more. Race fuel does not sit in a large tank vented to atmosphere and exposed to the elements like so many tanks at airports across the country, race comes in sealed containers that maintain its components. Will it matter to you in your sled and will you be able to tell the difference between av or race? Not likely. While most people do not pay attention to anything other than octane value, knowing the info about the other components of the fuel will really help you in selecting the appropriate fuel for your application. As atmospheric pressure decreases at elevation, selecting the lowest octane you can run for any given elevation will help you make the most power, in addition to selecting a fuel with a proper vapourization for your engine compression and operating temperatures. The less energy it takes to vapourize the fuel the better because as the elevation increases, the atmospheric pressure drop only makes it worse. Higher vapourization values take less energy to ignite, which is what you want in a colder climate and at higher elevations. Lower vapourization values in the fuel can leave unburned fuel in the cylinder, and are harder to ignite, meaning hard starting at elevation and in the cold.

The simple analogy that I give people is that race/av fuels are like diesel compared to 89 octane at the pump. Race/av fuel has less "light end" hydrocarbons in it than pump gas, because these light end hydrocarbons vapourize really quickly (Volatiles). This is because race fuels need to endure higher compressions where volatiles would pre-ignite (detonation). The lack of volatiles makes race/av harder to ignite on start up though and in colder weather, so if you need to run a 100% av/race at 3,000 ft (parking lot) but mainly ride at 6,000 ft where you only need a 50/50 blend, your sled may be harder to start at 6,000 ft and it will not make the most power with 100% av/race in the tank, so you want to run the lowest octane you can at the highest elevation you are riding. You need the lowest octane you can run to make the most efficient combustion process (often times heat) for the most efficient power.

Boosted sleds with electronic boost controllers or adjustable wastegates/blowoffs are easy, just run the 50/50 blend and just crank the boost down until you get to the higher elevations. Naturally aspirated sleds or fixed boost sleds take a little more fuel management (or throttle restraint on the trail.....), if you want to be making efficient power at the higher elevations, not a big deal but still more effort than just running one type of fuel. I've gone away from av gas this year because of the hassles of getting it, transporting it and not being able to fill up at the pump.

Sorry about the long winded explanation. Hope that helps in your fuel choice though.

Edit: re-read my post and realized it might be confusing, not looking to debate race vs av fuel as they are both leaded fuels but mainly to comment on blending of fuels and how your motor makes power based on what you give it to drink.

Coles notes version is this: Whether its race/av gas doesn't really matter as they are the same (generally speaking), but run the lowest octane you can and you will make the most power.

 

[overkill131313]

Modman......well said!

I'm trying to find a 45 gallon drum to fill at the airport, but I fill the sled right there and a few jerry cans. I normally run straight Av gas in the turbo tank and run up to 18-19 PSI....should I be running Av gas 100LL 50/50 with chevron 94? my new mod sled has 15 to 1 CR......what should I run in it to be safe at 3000 feet?

 

[canuck5]

Good write up Modman, and I agree 100 percent with the analagy that Race will always be more consistant in a sealed barrel than av gas. I personally on a boosted Nytro now use av gas because I hated mixing fuel it was a PITA and I always questioned my octane in my tank if I put too much pump gas in or had just say dumped a jerry can in with pump gas. I believe my buddy picks our AV gas up at the lacombe airport for 1.40/liter reigon so its a no brainer compared to the VP at 3.20/liter even mixing it at 50/50.

 

[moyiesledhead]

for your mix ratio's modman had a fel calculater posted a while ago..

MotorSports Racing Fuels - Racing Gas - Nitromethane - Methanol - Racing Lubricants - Additives - Race Fuels

 

[Modman]

Good write up Modman, and I agree 100 percent with the analagy that Race will always be more consistant in a sealed barrel than av gas. I personally on a boosted Nytro now use av gas because I hated mixing fuel it was a PITA and I always questioned my octane in my tank if I put too much pump gas in or had just say dumped a jerry can in with pump gas. I believe my buddy picks our AV gas up at the lacombe airport for 1.40/liter reigon so its a no brainer compared to the VP at 3.20/liter even mixing it at 50/50.

Well that's cheap for av gas ! I was buying it $1.86/L here last year, going through about $80-$90 worth a day on a big day, and I know its over $2/L here now. Biggest PITA is only having so much of it and driving a mini-tanker truck around. My one riding buddy also runs av so between us we had like 6-7 jerry cans in the truck for a weekend of riding. I opted for more displacement and less compression to make the same power, and I can do it on pump gas too.

 

[overkill131313]

so if I put back on a stock 809 head what compression would it be? and how much HP would I loose?

 

[oler1234]

so if I put back on a stock 809 head what compression would it be? and how much HP would I loose?

had a buddy do the same thing on a cutler 1100 twin. HP wise he didnt loose alot, it was just the throttle response was lacking. Still peppy, but once you have a tase of te hih comp head you may not want to go back.

 

[Modman]

so if I put back on a stock 809 head what compression would it be? and how much HP would I loose?

LOL you lost me a couple posts back - I'm assuming you got a new ride something based on an 809 triple from a Mach Z. Who built the motor, what head, what RPM you going to run, what pipes, porting etc. Lots of things can determine what fuel you need, if you have a wild port job then starting will be hard enough at elevation without adding race fuel in the equation so you may want to consider the stock head, but below 3,000 ft shouldn't be too bad for starting but you will need definitely need more octane with the 15:1 CR. There is corrected and uncorrected ratios for compression so you need to determine if you want the corrected or uncorrected ones (there is also a separate one for 4 stokes that accounts for dished or domed pistons - negative or positive values) so make sure you use the right formula. Corrected ratios use the effective piston travel (from port close to TDC - NOT the full stroke!). To determine the uncorrected value for your sled you need the bore, stroke and head volume in CC's. The manual for the stock 809 should list the compression ratio for the stock head, and I believe Doo lists the uncorrected value (probably something like 9:1), but if its like 5:1 then it might be a corrected value.

 

[Longhairfreak]

LOL you lost me a couple posts back - I'm assuming you got a new ride something based on an 809 triple from a Mach Z. Who built the motor, what head, what RPM you going to run, what pipes, porting etc. Lots of things can determine what fuel you need, if you have a wild port job then starting will be hard enough at elevation without adding race fuel in the equation so you may want to consider the stock head, but below 3,000 ft shouldn't be too bad for starting but you will need definitely need more octane with the 15:1 CR. There is corrected and uncorrected ratios for compression so you need to determine if you want the corrected or uncorrected ones (there is also a separate one for 4 stokes that accounts for dished or domed pistons - negative or positive values) so make sure you use the right formula. Corrected ratios use the effective piston travel (from port close to TDC - NOT the full stroke!). To determine the uncorrected value for your sled you need the bore, stroke and head volume in CC's. The manual for the stock 809 should list the compression ratio for the stock head, and I believe Doo lists the uncorrected value (probably something like 9:1), but if its like 5:1 then it might be a corrected value.

You got me a little confused I can only imagine how overkill is doing lol.