race fuel requirements

[IFSM8]

Hi all,

I was just wondering if you have to mix C-111 in a stock machine or can you run it straight. I am only going to use it in the hills, but have never done it or have any knowledge about it. Any help would be great? Is it worth it for a stock machine or should i just stick with premium?

Thanks

 

[Summiteer]

Don't waste your money. As far as I know it won't do you any good on a stocker.

 

[Lococoin]

Running higher octane fuel than your sled requires is a waste.

 

[HagmanMod1]

your sled will make less power on race gas if its not needed. higher octane burns cooler

 

[kennyblatz]

higher octane burns slower so from what i understand it will just result in a loss of performance in a stock machine. when your going to the hills the elevation you gain will reduce the oxygen your motor gets decreasing the octane you need in the first place being 91 if that, most stock sleds do fine on 87.
just my opinion

 

[raustincat]

yes running higher octane fuel in an engine that doesn't require it does nothing for u... like stated about it will run worse.

basically in a nut shell the lower the octane fuel it has a higher "heat of compression" which basically means if you run 87 octane in an engine that requires higher octane fuels just the piston going up creates enough heat of compression to ignite the fuel before the spark plug does the igniting thus you great a really high pressure system between the piston and cylinder head so you hear a violent explosion or a "ping." Higher octane fuels have a lower heat of compression so the fuel won't ignite prematurely... instead it will be ignited by the spark plug at exactly the right time... therefore no pinging! higher octane fuel is only required in higher compression engines

running a higher octane fuel in a low compression engine will just burn slower and cooler and will actually lower the performance of ur engine... all those guys that say oh yea i throw a tank of premium in the old sunfire once a month to run it hot and burn out the carbon build up have no clue what they are talking about.

And as stated above the higher elevation you are at the less dense the air is so your air fuel ratio will be such that the octane rating on your fuel that is required goes down as you increase in elevation... not exaclt sure at what rate this is but if you run 91 down at sealevel 87 will definitely work at 5000+ ft.

hope that sorta explains it a bit better... it is quite a bit more complicated than that but thats sorta a nutshell explenation.

Auzz

 

[IFSM8]

So what about C-10 unleaded? I was informed today that what you buy as premium 92 octane is not as pure and is less octane as advertised. He said some where around the 89 range i think. Thanks for the input guys!

 

[Uturn]

Race fuel in a stock motor is a waste of money and will hurt performance as stated above. 92 R/M pump octane fuel will be within 1 of advertised unless it is old fuel. If you are dealing with a station that sells lots of premium(any sled area) it shouldn't be a problem.

 

[apex69]

Race fuel in a stock motor is a waste of money and will hurt performance as stated above. 92 R/M pump octane fuel will be within 1 of advertised unless it is old fuel. If you are dealing with a station that sells lots of premium(any sled area) it shouldn't be a problem.

where is the proof when i raced we tested all the fuel we used the closest one was shell they were 3 points low the rest were up to 7 lower than they stated on the pumps

 

[JungleJim]

The reason why running a few tanks of premium through any vehicle every now and then is not related to the Octane but to the detergent package. Regular typically has a basic detergent additive package and for unbranded stations the absolute minimum required by Provincial legislation. Premium offerings can have significantly better detergent technology and amounts vs Regular thus the valves, seats, and injectors get cleaned out which improves your performance. Shell's V-Power (premium gas) has been proven to significantly clean up engine deposits in as little as two fills. Other majors have pretty good offerings too. Premium octane ratings are also certified by every batch received into terminals so if you are seeing a significant drop it could be you are getting a motor octane # given to you from the lab vs. the typical Research Octane + Motor Octane divided by two as used in North America... or old premium from a slow moving retail site. Best to alway get premium from a major brand at a fast moving busy site and avoid keeping "half" jerry cans around as the light ends of the gasoline dissipate quickly.

 

[Uturn]

where is the proof when i raced we tested all the fuel we used the closest one was shell they were 3 points low the rest were up to 7 lower than they stated on the pumps

How were you testing? We run all our samples on gas chromatographs and we regularly get the samples verified by the Alberta Research Council lab. Our spec is very tight.

 

[hintonatv]

yes running higher octane fuel in an engine that doesn't require it does nothing for u... like stated about it will run worse.

basically in a nut shell the lower the octane fuel it has a higher "heat of compression" which basically means if you run 87 octane in an engine that requires higher octane fuels just the piston going up creates enough heat of compression to ignite the fuel before the spark plug does the igniting thus you great a really high pressure system between the piston and cylinder head so you hear a violent explosion or a "ping." Higher octane fuels have a lower heat of compression so the fuel won't ignite prematurely... instead it will be ignited by the spark plug at exactly the right time... therefore no pinging! higher octane fuel is only required in higher compression engines

running a higher octane fuel in a low compression engine will just burn slower and cooler and will actually lower the performance of ur engine... all those guys that say oh yea i throw a tank of premium in the old sunfire once a month to run it hot and burn out the carbon build up have no clue what they are talking about.

And as stated above the higher elevation you are at the less dense the air is so your air fuel ratio will be such that the octane rating on your fuel that is required goes down as you increase in elevation... not exaclt sure at what rate this is but if you run 91 down at sealevel 87 will definitely work at 5000+ ft.

hope that sorta explains it a bit better... it is quite a bit more complicated than that but thats sorta a nutshell explenation.

Auzz

So what would VP Ultimate 4.2 do then? It is "oxygenated", leaded and has a motor octane rating of 102. Energy value is an expression of the potential energy in the fuel. The energy value is measured in BTUs per pound, not per gallon. The difference is important. The air:fuel ratio is expressed in weight, not volume. Generally speaking, VP's fuels measure high BTUs per pound and thus, have a higher energy value. This higher energy value will have a positive impact on horsepower at any compression ratio or engine speed. Try running VP in anything for a while ,and then stop. You will notice a huge difference. Switch back to premium pump and you will think there is something wrong with your machine.

To get the straight dope on racing fuels visit VP Racing Fuels web site and educate yourself. Go to and look for the link called "the four fuel properties. It's a good read.

 

[IFSM8]

On the VP site i found that MS 109 Is the right fuel for a stock 2 stroke snowmobile. I think i am going to give it a try.