Why use race fuel?

Curtis Bosarge, Jr · Joined: 08 Sep 2001 Posts: 6 Location: Des Allemands, La

Someone asked me today "Why do you use C-12 in your shifter?" I replied "That's what I've always been told to use. C-12 or equivalent." Then I realized how lame that was. Considering this guy builds race car engines for a living, I felt that his question had merit.
So, I ask the Tech Hit Squad; Why use race fuel instead of pump gas? Is there a scientific reason? Hard data, or just coincidental bad experiences.

Thanks,

Curtis

Don McGregor · Posted: Sat Sep 08, 2001 6:39 pm Post subject: Why use race fuel?

One good reason is the inconsistancy of pump gas. It can sometimes work very well in a kart, and sometimes very poorly. It just depends on the seasonal additives and compostion. The seasonal additives can also lead to fuel being found illegal during tech, which makes it not a good gamble.

Don

P.S. One time at a club race no one had any race fuel left to sell so we bought some pump gas from a local station. We went so fast after putting it in, most of the competition went and bought some!

Jack Burroughs · Joined: 18 Jul 2001 Posts: 144

Get yourself a gasoline hydrometer, learn how to use it, you may find a few interesting things like temp and detonation control, getting consistant performance, etc..

John Neilson · Posted: Sun Sep 09, 2001 7:17 am Post subject: Why use race fuel?

Simple, consistancy, both in performance and in the tech procedure.
John

Brian Kay · Posted: Sun Sep 09, 2001 12:17 pm Post subject: Why use race fuel?

That would be a very good question if you were running a STOCK CR125 motor. When you consider the factors that MANDATE the use of high quality fuel, it becomes obvious why we all run race gas.

*Compression
*Timing
*Temperature
*RPM

All of the above are altered from stock form, thus requiring the use of high quality / high octane fuel. Think of race gas as your motor's protection from certain disaster. After all it is a cooler / slower / more consistent burning fuel, which is opposite what some people think.

If your motor IS stock, I would still suggest you use something in the 98 to 100 octane range. Sure you can run 93 octane pump gas, but there's no guarentee it will pass fuel tech (alcohol) and I promise it wont be consistent (jetting).

Hope this helps,

Brian K - T2 RaceKarts

Keith Archambeau · Posted: Mon Sep 10, 2001 1:32 pm Post subject: Why use race fuel?

Chris, The above comments are very accurate. Actually with pump gas, in the 100cc Yamaha classes you can get more power. Due to the low compression, timing ports ect. Legal of course. The problem with the pump gas is, the additives used in most formulations will and are somtimes detected as the same as nitro, alcohol, excess benzine ect. If pump gas was allowed this would open the door for competitors to start adding ingredents. Swearing that they bought it that way. The race gas rules prevent garage chemist from cheating & also keeps fires & cancer at a lower level. Good rule!
RACE!

Doug Welch · Posted: Mon Sep 10, 2001 1:55 pm Post subject: Why use race fuel?

Most pump gas here in the high altitude areas will not pass the fuel test as they add oxygenators to lower emmisions. Same is true for those areas of the country where pollution controls are in effect. If you use a quality race fuel and it comes from a reputable source, you should never have a problem with passing a fuel test anywhere. I have seen pump fuel test +40 or more on the digitron gage. About the same as if you added 5% nitro or any one of a dozen other good things that actually boost performance. Good old race gas (C-12) will come in -40 or so. Using a castor oil will bring that number up a bit but not enough to really mean anything as far as the test goes.

If you need to lower the octane rating because your motor is more or less stock, add more oil.

Doug

Sean Robbins · Posted: Mon Sep 10, 2001 3:32 pm Post subject: Why use race fuel?

One downside with pump gas is detonation. I once ran 93 octane in my shifter--it ran well. However, the motor wouldn't start the next weekend. When I pulled the head, the whole combustion chamber looked like it had been sandblasted. The few bucks I saved in fuel costs did not offset the $400 or so I spent fixing the damage.

Curtis Bosarge · Joined: 18 Jul 2001 Posts: 28 Location: Des Allemands, La.

I understand now. At least I'm no longer relying on "Because" as a reason. Thanks to all for the excellent feed back.

Just for the record, I have never used pump gas in our shifter, and will continue to run C-12 or equivalent. I've already done two complete tod-ends this year, don't need any more failures for a while. $5/gal is a bargain compared to cylinder & piston cost. Just want to race for a while.

I will send this thread to my friend.

Thanks again.

Curtis