which is faster- VP C-11 or C12 - Page 2

Ed Wright · 05-07-2012, 09:29 AM

I may be doing something wrong. After some tuning my LT1 likes C11. Never one issue with fuel check. I don't drain or seal anything. Your results may vary. LOL

KRatcliff · 05-07-2012, 10:06 AM

Ed,

You are not doing anything wrong. I think C11 is easier to tune than C12 in our stuff. They both seem to be about as fast, but I prefer C11.

Pedigo,

Quit posting and get back to putting your engine together! Either you show up and race or you get to be my pit bitc...

Pedigo Perf · 05-07-2012, 10:26 AM

[QUOTE=KRatcliff;325281]Ed,

You are not doing anything wrong.

How can you be racing and not doing ANYTHING wrong.... KYLE?

KRatcliff · 05-07-2012, 11:05 AM

True!

Mike Croley · 05-07-2012, 11:50 AM

Quote:

Originally Posted by Aubrey N Bruneau

excellent, Alan !
I'm about to trailer 750 miles one way, to the only race I'll be able to attend, with $210.00 of fuel, that probably won't pass for qualifying ?
ah yes, this is getting better and better !

Interesting about tyhe C11. Good to know.

Let me make a suggestion Aubrey . As of the beginning of the year , Renegade Racing Fuels are NHRA and IHRA legal . Contact them and see if they have any dealers near you . Renegade will get you the same or better performance than you have now at a lot less money . If they don't currently have a dealer in your area , I imagine it would be well worth your while to talk to them and see about becoming a dealer . Or if you know of a shop that would be a good candidate to sell race gas , have them contact Renegade .
I know race fuel is difficult in Canada at the moment , so this would be an ideal time to make a move .

Alan Roehrich · 05-07-2012, 12:10 PM

Quote:

Originally Posted by Pedigo Perf

How can you be racing and not doing ANYTHING wrong.... KYLE?

Amen.

Aubrey N Bruneau · 05-07-2012, 12:43 PM

Does this mean that the more a person does wrong, the better racer thay are ???
wow !

I'm the best
I'm the best
the best, I tell you

Just checked, Mike. There's a dealer in Calgary.
The fuel seems to be VERY VERY 2 stroke oriented though ?

Altidude must make quite a difference. Didn't even think of it before.
I tuned carefully, with some pretty high tech equipment on a dyno, here at 3000+ ft, whispy air, using C11.
Went to Mission, at near sea level ( 700 ft cool air I believe ). When I got there, I bumped all 8 jets up 2 steps, and bought C12 fuel that ended up getting mixed with about half a gallon of C11 that was in the tank. Car went almost 5 MPH faster than it ever went before.
Whatever I did... I want to try and repeat it.
I know that may be over simplifying things, but I don't have a data logger, ect, to verify my tune at the track, and I can't really afford to make a half dozen tuning-passes ( car is somewhat hard on parts ).

Mike Croley · 05-07-2012, 12:57 PM

Quote:

Originally Posted by Aubrey N Bruneau

Does this mean that the more a person does wrong, the better racer thay are ???
wow !

I'm the best
I'm the best
the best, I tell you

Just checked, Mike. There's a dealer in Calgary.
The fuel seems to be3 VERY VERY 2 stroke oriented though ?

Altidude must make quite a difference. Didn't even think of it before.
I tuned casefully, with some pretty high tech equipment on a dyno, here at 3000+ ft, whispy air, using C11.
Went to Mission, at near sea level ( 700 ft cool air I believe ). When I got there, I bumped all 8 jets up 2 steps, and bought C12 fuel that ended up getting mixed with about half a gallon of C11 that was in the tank. Car went almost 5 MPH faster than it ever went before.
Whatever I did... I want to try and repeat it.
I know that may be over simplifying things, but I don't have a data logger, ect, to verify my tune at the track, and I can't really afford to make a half dozen tuning-passes ( car is somewhat hard on parts ).

The Renegade web site is pretty heavy on motorcycle race fuels , they're producing the top MX fuels in the sport . Once you look past the MX fuels though , they have a complete lineup of race fuels for drag , circle track , marine , etc .

Ed Wright · 05-07-2012, 10:59 PM

Btw, I do not want to sound like I was disputing what Alan said. I have had too many friends experiencing the fuel check issues with C12 he mentioned. I would never use it myself.

FastbackTom · 05-11-2012, 10:58 AM

I attended a fuel seminar at Sema about 10 yeas ago... the guy was the NASCAR liaison from Unical, and offered up some real good advice (for us non-chemist-types) on race fuels in general. I've also learned a lot from my own experience with dynoing my own engines, talking with engine builders about various compression ratios and cranking compressions. I also have a fair amount of experience with VP's C12, and a little with C14 and C14+. My current engine is built around VP's C12, the mandated spec fuel for this other class I run (outside of NHRA SS).

-Quality gasoline contains the same number of BTUs per gallon regardless of octane. Higher octane does not mean more power (a common misconception)

-Octane is a measure of burn rate, or the way I view it, burn retardant. All things being equal, the higher the octane number, the slower the burn.

-Higher dynamic compression speeds up burn rate. A high compression engine with a cam that has lots of duration my have a lower dynamic compression ratio than you think. Cranking compression, measured with a traditional (quality) compression tester, is a decent way to determine dynamic compression on a normally aspirated engine.

-The simple way I look at octane; the best octane for my engine is the lowest that doesn't allow it to it knock.
-Too high an octane will make it lazy, and not want to rev up
-use sealed containers, drain your fuel after a race weekend... The chemicals that increase octane by retarding burn rate, are the lightest in the mix. They tend to 'boil off' at room temperature, lowering it's octane rating.
-UV light also has a negative effect on race gasoline. Those opaque poly fuel jugs allow UV to get through, I've been advised to use the colored ones that block UV, and store them out of direct sunlight. Also, poly jugs are not a perfect seal, the lighter chemicals will seep through poly jug material, when heated pressurize the cap and make it leak, and the vapor escape when you open the cap.
-The 2-valve wedge head engines I play with will not run on VPC12 with 300psi on cranking compression without rattling, but when brought back to 250psi, they will run on C12. Realize that's only one data point for one type of engine, but it may be an indicator of octane required for 250psi cranking compression.

05-07-2012, 09:29 AM	#11
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: which is faster- VP C-11 or C12 I may be doing something wrong. After some tuning my LT1 likes C11. Never one issue with fuel check. I don't drain or seal anything. Your results may vary. LOL __________________ Ed Wright 4156 SS/JA

05-07-2012, 10:06 AM	#12
KRatcliff Senior Member Join Date: Sep 2011 Posts: 763 Likes: 75 Liked 524 Times in 141 Posts	Re: which is faster- VP C-11 or C12 Ed, You are not doing anything wrong. I think C11 is easier to tune than C12 in our stuff. They both seem to be about as fast, but I prefer C11. Pedigo, Quit posting and get back to putting your engine together! Either you show up and race or you get to be my pit bitc...

05-07-2012, 10:26 AM	#13
Pedigo Perf Member Join Date: Feb 2008 Location: Wichita Ks Posts: 383 Likes: 70 Liked 30 Times in 17 Posts	Re: which is faster- VP C-11 or C12 [QUOTE=KRatcliff;325281]Ed, You are not doing anything wrong. How can you be racing and not doing ANYTHING wrong.... KYLE?

05-07-2012, 11:05 AM	#14
KRatcliff Senior Member Join Date: Sep 2011 Posts: 763 Likes: 75 Liked 524 Times in 141 Posts	Re: which is faster- VP C-11 or C12 True!

05-07-2012, 12:43 PM	#17
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: which is faster- VP C-11 or C12 Does this mean that the more a person does wrong, the better racer thay are ??? wow ! I'm the best I'm the best the best, I tell you Just checked, Mike. There's a dealer in Calgary. The fuel seems to be VERY VERY 2 stroke oriented though ? Altidude must make quite a difference. Didn't even think of it before. I tuned carefully, with some pretty high tech equipment on a dyno, here at 3000+ ft, whispy air, using C11. Went to Mission, at near sea level ( 700 ft cool air I believe ). When I got there, I bumped all 8 jets up 2 steps, and bought C12 fuel that ended up getting mixed with about half a gallon of C11 that was in the tank. Car went almost 5 MPH faster than it ever went before. Whatever I did... I want to try and repeat it. I know that may be over simplifying things, but I don't have a data logger, ect, to verify my tune at the track, and I can't really afford to make a half dozen tuning-passes ( car is somewhat hard on parts ). __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409 Last edited by Aubrey N Bruneau; 05-08-2012 at 12:40 AM.

05-07-2012, 10:59 PM	#19
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: which is faster- VP C-11 or C12 Btw, I do not want to sound like I was disputing what Alan said. I have had too many friends experiencing the fuel check issues with C12 he mentioned. I would never use it myself. __________________ Ed Wright 4156 SS/JA

05-11-2012, 10:58 AM	#20
FastbackTom Junior Member Join Date: May 2012 Posts: 7 Likes: 0 Liked 0 Times in 0 Posts	Re: which is faster- VP C-11 or C12 I attended a fuel seminar at Sema about 10 yeas ago... the guy was the NASCAR liaison from Unical, and offered up some real good advice (for us non-chemist-types) on race fuels in general. I've also learned a lot from my own experience with dynoing my own engines, talking with engine builders about various compression ratios and cranking compressions. I also have a fair amount of experience with VP's C12, and a little with C14 and C14+. My current engine is built around VP's C12, the mandated spec fuel for this other class I run (outside of NHRA SS). -Quality gasoline contains the same number of BTUs per gallon regardless of octane. Higher octane does not mean more power (a common misconception) -Octane is a measure of burn rate, or the way I view it, burn retardant. All things being equal, the higher the octane number, the slower the burn. -Higher dynamic compression speeds up burn rate. A high compression engine with a cam that has lots of duration my have a lower dynamic compression ratio than you think. Cranking compression, measured with a traditional (quality) compression tester, is a decent way to determine dynamic compression on a normally aspirated engine. -The simple way I look at octane; the best octane for my engine is the lowest that doesn't allow it to it knock. -Too high an octane will make it lazy, and not want to rev up -use sealed containers, drain your fuel after a race weekend... The chemicals that increase octane by retarding burn rate, are the lightest in the mix. They tend to 'boil off' at room temperature, lowering it's octane rating. -UV light also has a negative effect on race gasoline. Those opaque poly fuel jugs allow UV to get through, I've been advised to use the colored ones that block UV, and store them out of direct sunlight. Also, poly jugs are not a perfect seal, the lighter chemicals will seep through poly jug material, when heated pressurize the cap and make it leak, and the vapor escape when you open the cap. -The 2-valve wedge head engines I play with will not run on VPC12 with 300psi on cranking compression without rattling, but when brought back to 250psi, they will run on C12. Realize that's only one data point for one type of engine, but it may be an indicator of octane required for 250psi cranking compression.