which is faster- VP C-11 or C12

[Alan Roehrich]

Aubrey, the best advice I can give you with C12 is to NEVER, under ANY circumstances, allow it to be exposed to the atmosphere for long periods of time. keep it sealed up in any container you have it in. Take your jugs and turn them upside down. If they leak, either fix the leak or replace the jug. Either drain your fuel cell, or seal all the vents. If you buy it by the drum, keep the drum sealed with the bungs, and use bung wrenches.

I should, in the interest of fairness and honesty, disclose that we do not use VP C12 anymore, we're on the Sunoco program now, we use Sunoco Supreme.

[Ed Carpenter]

Originally Posted by Alan Roehrich

Aubrey, the best advice I can give you with C12 is to NEVER, under ANY circumstances, allow it to be exposed to the atmosphere for long periods of time. keep it sealed up in any container you have it in. Take your jugs and turn them upside down. If they leak, either fix the leak or replace the jug. Either drain your fuel cell, or seal all the vents. If you buy it by the drum, keep the drum sealed with the bungs, and use bung wrenches.

I should, in the interest of fairness and honesty, disclose that we do not use VP C12 anymore, we're on the Sunoco program now, we use Sunoco Supreme.

X2 on the Sunoco never had a problem.

[Aubrey N Bruneau]

Hey, I know what....
I'll drain this 10 gallons of C12 out of the car, and add it to the pump gas in the fuel tanks on my tow rig ! About 1 gallon C12 to 5 gallons pump premium. DAMN this truck ran nice when I did that before ! ( great for pulling the big hills through BC ! ) Pretty expensive haul though.

I used Sunoco before. Absolutely, stuff worked just fine, and seemed easier to tune too.
We'll see. Race fuel in Canada is awful expensive.

Bought two sealed 5 gallon drums, Alan.... fresh batch. Should be good.

[rustbucket79]

Might be worth hauling the sealed pails to the fuel check station and have it tested before you put it in the car. Make sure you have fresh fuel up to the fuel check access point prior to making a pass, would be a shame to have some old fuel screw you're first qualifier.

[Pedigo Perf]

Originally Posted by rustbucket79

Might be worth hauling the sealed pails to the fuel check station and have it tested before you put it in the car. Make sure you have fresh fuel up to the fuel check access point prior to making a pass, would be a shame to have some old fuel screw you're first qualifier.

After you refill fuel system in the car, take it to fuel check and make sure it passes before you make a run. It may take some flushing out to get rid of old C12 to the point you will pass fuel check with the new fuel in the car. Speaking from experience.

Also, the specific gravity is significantly different from C11 to C12 and requires jet change just to get an apples to apples comparison. Of course there are other considerations such as fuel curve change and timing requirement may even change a little. Replacing one fuel for another without re-tuning wont give you a fair assesment.

Lower compression (less than 11-1) engines typically make better power on C11, my combo is closer to 12-1 and it make about the same power either way so I run C12 as it is easier to get and cheaper too. I have considered trying C11 at Denver but we haven't been able to test there. I have a hunch it may be faster at altitude as cylinder pressure drops up there.

Tracy Pedigo

[Ed Wright]

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]

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...

[Mike Voth]

Originally Posted by Ed Wright

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

Same with our Monte Carlo. More power with the C11, no failed fuel checks.

[Jack Matyas]

C-11 has always been faster for me and has never failed fuel check in one of my cars .............The fuel check issues with C-12 have always been with fuel that came from 54 gallon containers .Yes , I know that sounds odd but I've not heard about problems with fuel from 5 gallon pails .

[art leong]

I've used C12 since I built my car (over 5 years) and I've never had a problem with fuel . I even left about 3 gallons in my fuel cell for 4 months and just figured it was bad but had it checked anywaycheck. much to my surprize it was fine. That was without capping the vent, and in an unheated garage.