Super Stock Race Fuel
 

I have a race gas question.

I have always run VP C-12. Now, my local distributor only carries Sunoco. I can still get VP, but have to drive a bit farther to get it.

Will the 110 octane Sunoco work as well as the VP?

Any help is appreciated.

Thanks.

Jeff Goss
6990 SS/MA

Better.

Jeff,

Check the 'reid vapor pressure' differences between the fuels if possible, especially with a low compression motor. Reid vapor pressure (RVP) is the ability of the fuel to vaporize. VP publishes their RVP but not sure about Sunoco.

Octane is a 'burn retardent' with basically no impact on fuel energy content (btu/lb); it ust affects how it burns.

Don,

Thanks for the reply.

I found a website that lists the RVP for the different race fuels.

http://www.smithtex.com/racing/fuelcomp.html

It shows Sunoco Supreme with 8.0.

VP C-12 is 7.75.

I need to read up a little more, but Sunoco should be in the ballpark or a little better? The higher RVP should make it vaporize quicker?

Motor is a 327-250 horse with the 4GC Carb. Small valves and 10.25:1 compression.

Jeff

Jeff,
When Steven made up that list he also included a list of Terms we use with fuel. It give you some info about what all the terms in the chart are.
Go back and take a look at it.


Adger Smith

The problem you can run into is inadvertantly mixing the VP fuel in with your Sunoco fuel as NHRA uses VP as the "official" fuel and Sunoco wont be sold at an NHRA event. Even straight Sunoco seems to be a problem with NHRA tech at times.
I would rather use Sunoco as it's roughly 30% cheaper than VP. Personally, in my application, I can't tell any difference between the two brands; other than in the wallet.

NHRA #7494 SS/H
1970 AMC AMX
"Best Appearing" @ NHRA '06 Pacific Sports Nationals
JeffLeeAzRealty@Qwest.net
602-418-9797

Thanks a bunch for the good info!

Jeff

Jeff i've always run sunoco 110....my buddy Mike Galuk had his car @ my house having some work done to it (changing oil plugs) well while we were messing around with it we ran it out of fuel...C12.....all i had was sunoco....so we put that in the car & went and got him a jug of it. he left & went to Byron for a div. race.....it was the quickest he had ever run. (& this ws in the middle of summer)

novamoation

Jeff, please EMail me your phone number and a good time to reach you. I live in W.V. so there is a time difference. Mike. LGaluk@aol.com

Mike Galuk
JOE COOL RACING
Stock-2080

Jeff (Goss):

Reid vapor pressure numbers are as follows...

...the lower the RVP number is numerically, the less volatile (i.e., harder to vaporize) the gasoline is.

Using your info, the C-12 is slightly less volatile than the Sunoco, however I would consider both fuels fairly close in range.

I would also compare the density of the fuels to determine impact on your carb settings.

And as Jeff Lee pointed out, I wouldn't mix them, unless you like hanging out at fuel check and answering lots of questions...

Thanks alot for the good info.

I think what it comes down to is I'll just need to try it. Too many variables in each combination for my small brain-LOL!

Jeff

I looked at Sunoco's and VP's web sites to compare specs. on there fuels and the #'s posted above are not the same as the #'s given by the manufacturers on there web sites. The main difference being RVP.
VP C-12 has a RVP of 7.30,
Sunoco Supreme has a RVP of 6.3
Octane #'s are similar 108 to 110
Spec. Gravity are similar .717 to .715

My question is how well does the Sunoco Supreme (BLUE) work in higher compression motors? I.E., 396/375 stocker

THX--Matt

Jeff, I have been using Sunoco for the past two years in my Super Street Nova, and haven't seen an issue with horsepower.
I did have a conversation about the difference in VP and Sunoco, with Mark Kidd of Twin Falls Idaho, who has spent alot of hours testing each fuel on his Dyno, and he claims that the VP in good for approx. 7 horsepower in a high compression test mule.
I still dont see any difference in my case, running 13-1 in a small block Chevy.
However, last year a good friend of mine at the first division race (Div 6), did have a problem with Sunoco passing the fuel check with his L/SA Malibu wagon.


S/ST6608,S/Pro D608

Steve,
Mark Kidd sees the same HP improvement I have seen in High compression engines. That could be due to VP reformulating the C-12 a couple of years ago. It seems to work better in higher compression engines now. I would assume there is little difference in low compression engines. Lower compression engines might even do better with the lower octane fuel.
In testing I have expereienced a 26 Hp difference in VP C-14 & Sunoco Maximal in the Splayed Valve V-6 I run. This V-6 engine is a very high RPM & high compression engine. It just likes the VP C-14, but makes even more power on VP C-25. Just try the fuel & see if it works for your combination. Each engine & engien combination could be different. I guess that is why VP lists over 50 different fuel mixtures.

Adger Smith

Thanks Steve.

I think my lower compression will make the two fuels about equal.

I am a little worried about fuel check. I guess if we see a big DQ next to my name on the qual sheet in Mission we'll know why-LOL!

I have met your friend with the Malibu wagon-in Boise a few years ago. Good guy!

Jeff

Jeff, don't worry about passing fuel check. I have been racing with Greg for about four years now and have never seen him fail. Good luck, Mike

Mike Galuk
JOE COOL RACING
Stock-2080