V.P. C-11 vs. C-12 - Page 2

Andrew Hill · 09-11-2015, 01:45 PM

Quote:

Originally Posted by Mike Croley

NHRA may not want to add any more fuel blends to the list, but we'll see.
I'll give you some info on fuel specs.
Sunoco 110 motor octane is 106
VP 110 motor octane is 107
VP C-12 motor octane is 108
The Renegade Pro 110 motor octane is over 108

Mike, could you give us a little info on how motor octane vs research octane differ? Is motor octane what's important to us?

Mike Croley · 09-11-2015, 03:48 PM

The designation of "110" race fuel is derived exactly the same way the "87" octane designation at your local gas station pump is. And they both mean the same thing, so you have something to compare race fuel and pump gas.
Both race fuel and pump gas are tested in two ways. One test is called the Research Octane. The results of the research octane test are more pertinent to low compression, low rpm engines. The other test is the Motor Octane test. It relates much more to racing engines, higher compression and high rpm.
Each fuel goes through both tests, then the results are added together to get the R+M/2 number that you see posted on gas pumps and on the specs for race gas.The higher the Motor Octane number, the more race gas you're getting for your money. For instance, the Renegade Pro 110 is listed as R+M/2 of 110.5. The Motor Octane is 108,and the Reserch Octane is 113. Added together and then divided by 2 gives you 110.5 octane.

Mike Croley · 09-11-2015, 04:00 PM

There are other important aspects of racing fuel of course. Specific Gravity, and RVP ( Reid Vapor Pressure ) are two that matter.
All brands and all blends of racing fuel have different specs. 4 different brands of 116 will all have different Specific Gravity and RVP numbers. If there was only one RVP, or one Specific Gravity that was the best, all manufacturers would just plug those numbers into every blend and be done with it. Each manufacturer works very closely with racers and engine builders to come up with blends that make power, make torque, and most important, control detonation and pre-ignition.

James L Miller · 09-11-2015, 07:32 PM

https://en.wikipedia.org/wiki/Octane_rating

Usually the short chain alkanes like methane and ethane have the higher octane ratings. And they usually are the ones that boil off first, so the old stale/flat gas has probably lost the good stuff and eventually you end up with paint thinner or varnish.

That chart I think is wrong on benzene. I've always heard it's off the chart and they couldn't get an engine to knock on it, so MON of 130 or so. I think that is the top number in the rating system.

All these ratings are performed on a single cylinder engine made by Waukesa. It probably doesn't look like anyone's racing engine. Perhaps closer to a farm tractor engine.

http://www.waukeshacfr.com/f1-f2/

09-11-2015, 03:48 PM	#12
Mike Croley Member Join Date: Apr 2010 Posts: 182 Likes: 0 Liked 0 Times in 0 Posts	Re: V.P. C-11 vs. C-12 The designation of "110" race fuel is derived exactly the same way the "87" octane designation at your local gas station pump is. And they both mean the same thing, so you have something to compare race fuel and pump gas. Both race fuel and pump gas are tested in two ways. One test is called the Research Octane. The results of the research octane test are more pertinent to low compression, low rpm engines. The other test is the Motor Octane test. It relates much more to racing engines, higher compression and high rpm. Each fuel goes through both tests, then the results are added together to get the R+M/2 number that you see posted on gas pumps and on the specs for race gas.The higher the Motor Octane number, the more race gas you're getting for your money. For instance, the Renegade Pro 110 is listed as R+M/2 of 110.5. The Motor Octane is 108,and the Reserch Octane is 113. Added together and then divided by 2 gives you 110.5 octane. Last edited by Mike Croley; 09-11-2015 at 03:52 PM.

09-11-2015, 04:00 PM	#13
Mike Croley Member Join Date: Apr 2010 Posts: 182 Likes: 0 Liked 0 Times in 0 Posts	Re: V.P. C-11 vs. C-12 There are other important aspects of racing fuel of course. Specific Gravity, and RVP ( Reid Vapor Pressure ) are two that matter. All brands and all blends of racing fuel have different specs. 4 different brands of 116 will all have different Specific Gravity and RVP numbers. If there was only one RVP, or one Specific Gravity that was the best, all manufacturers would just plug those numbers into every blend and be done with it. Each manufacturer works very closely with racers and engine builders to come up with blends that make power, make torque, and most important, control detonation and pre-ignition.

09-11-2015, 07:32 PM	#14
James L Miller Member Join Date: Apr 2005 Posts: 494 Likes: 6 Liked 25 Times in 16 Posts	Re: V.P. C-11 vs. C-12 https://en.wikipedia.org/wiki/Octane_rating Usually the short chain alkanes like methane and ethane have the higher octane ratings. And they usually are the ones that boil off first, so the old stale/flat gas has probably lost the good stuff and eventually you end up with paint thinner or varnish. That chart I think is wrong on benzene. I've always heard it's off the chart and they couldn't get an engine to knock on it, so MON of 130 or so. I think that is the top number in the rating system. All these ratings are performed on a single cylinder engine made by Waukesa. It probably doesn't look like anyone's racing engine. Perhaps closer to a farm tractor engine. http://www.waukeshacfr.com/f1-f2/ __________________ Mopar 2 Ya!