Racing Gas
 

We do not have the weather extremes that are common to the North East. On several occasions I have in the past ran about 10 gallons straight of Unocal 114 leaded. There is a HUGE difference in throttle response, idle, and all around drivability, it definately smells different and the pipes get that NICE tan color that can't be obtained with unleaded.and your plugs color quickly to aid in asessing your tune up. There are a few Unocal stations locally that have a pump designated for 100 octane unleaded race gas too.

Some of you may remember the old Standard Station/ Chevron White pump leaded @ 103 octane at 43 cents a gallon. That's another story......
Currently 91 octane is the norm for all the stations in our area.

..........Rick

Rick:

Unlesss your timing was retarded because of detonation problems, and you advanced it when you put the 114 in, its your imagination. Many articles have been written and tests done to prove this. Higher octane gas burns slower, not faster.

It does smell better and cleans the tips of the pipes, but your car is not faster. If you don't believe me, which I know you don't, bring it to the dragstrip.

I agree with Jeff.....the only thing octane does is control detonation....more octane will allow you to play with your timing. The reason lead was put into gas was for use as a lubricant for the valve guides and seats....

I only know what i read. One of the car magazines several months ago ran an Octane and gas test on a "built" 340 Mopar. I think it was Popular Hotrodding.

Dispelled some of my long held cherished beliefs about gas, octane, timing, and power.

They found that indeed, as the gas "quality" increased (they also ran tests with octane boosters), starting with 87 octane, going up to 114 octane, that the motor did make more power, i think like 15 more horses as i recall over baseline. They also found that on this specific engine, trying to increase the timing, to take advantage of the higher octane, only dropped the power a bit.

It seems that internal combustion is a very complex thing, and it is far too simple to state that all higher octane does is burn slower.

This article did change how i run at the drag strip, i do run race gas, and leave my timing alone. If the original poster noted his car ran better, perhaps it is because (at least here in SC) we are still getting winter gas, with its higher Reid vapor pressure, and i can tell exactly by driving when they start in the fall, and cease in the spring. My custom engine for sure runs much better, especially in hot stop and go traffic, with less fuel percolation, on the summer blend.

I often put in about 10 bucks of 100 octane, which i can get at the pump here, it does seem to improve my winter gas drivabilty some, by making the gas less volitile.

Now define the word "built" Engines are built with a certain CR and to run on a certain octane...very easy to pick up HP if the engine was made to run on 94 and you start off using 87....After you pass the point of octane that your engine was made to run on, more will do you no good....as far as winter and summer gas, your engine will run cooler on summer gas...you're running more gas through the engine, thus having a cooling effect..winter gas has more oxygen, thus making your engine run hotter...just increase your jets in the winter and you won't notice a difference, might even pick up a couple of horses because of burning more oxygen......

Jeff,
Contrary to your informative articles, the test can be set up to show a power / driving difference, or not, without jockeying timing. The people writing the articles almost know what they are talking about.
The missing link here is the fuel density. Auto fuels are getting less dense. It even changes among brands. Think what this does to a float setting.
Aircraft Airframe and Powerplant technicians have been on top of this now for awhile. Airplanes are a place where the technology is further behind than Cobras. A guy buys fuel for his plane from one place and the engine misses and hicups, and buys another brand and all is well. They check the float setting and it is within parameters. Usually barely though.
There is no reason why a guy in a cobra could change fuel and not notice a difference in how it runs. It doesn't have to be his "imagination".
Bob

webebob:

Go to the dragstrip and prove me wrong. I guess all of the magazine writers are idiots.

Hal:

How much faster do you go wih the race gas?

Jeff,

The posters claim was "There is a HUGE difference in throttle response, idle, and all around drivability, it definately smells different and the pipes get that NICE tan color that can't be obtained with unleaded.and your plugs color quickly to aid in asessing your tune up."

And your reply was "its your imagination"

And now you say I have to go to the drag strip to prove something to you!? Nah. Take it for what you feel its worth. Add some brain power to it ....like.... aviation fuel is very heavily regulated and it is having similar issues. Just think how much variance there must be in un-regulated automotive fuel. Could someone really notice a difference in drivablility?

I personally don't think the poster was lying. But if some hot rod magazine says he was........ well then ...... that is good enough reason for me! I'm off to the drags! Ye Ha! Your right! Drag racing it is. Like I need that much of an excuse! Lets go.

Bob

If a car is set up right, to begin with, ie plugs heat range, carb jets, timing, idle..etc etc You will not get anymore performance from using a higher octane fuel than what you need...with the heavy regulation on avgas it's a pretty scary thought that someone would actually fly a plane that misses and hiccups.....

webebob:

Did I call him a liar? It sure is great that you are putting words in my mouth. Have you ever heard of a placebo? It is commonly accepted that higher octane does not produce more hp in an engine that doesn't need it.

What does aviation fuel have to do with the discussion? I personally don't give a rats ass if you or anybody else wants to waste their money. I have watched with my own eyes my friend Nova (14:1) go slower on 114 octane gas than it did on 110. Maybe my eyes wern't reading the time slip correctly.

Nova.... nice

There is a simple test you can do on the 114 and 110 that explains why the 114 went slower (keeping in mind that according to you there should be NO difference but there was),
Oh geez, skip it,

Have a nice day
Bob

Bob:

You need to learn how to read (or play fair). Where did I say that there is no difference. I said no more hp. No more means no more and could mean less.

I wish my car was as fast as his small block Nova. 9.90's with one naturally aspirated four barrel .

Are you going to DVSFII? Would love to go to the strip with you Friday night.


Just having fun:

Rather than get into the typical whizzing contest that always seems to result when mythology meets fact I'll just refer any of you who might be interested in a well researched article about lead additive in fuel to the Spring 2002 publication of "American Heritage of Invention and Technology"

There is an article about Thomas Midgley who discovered both lead additive (later trade named Ethyl) AND the refrigerant gas that became known as R-12/R-22 (trade name Freon).

This excellent publication is printed quarterly, and deals with a wide range of subject matter. You can get a sample issue or a full subscription on their web site www.americanheritage.com . They also have excerpt articles from the printed magazine on the site, but the above referenced one is not one of them.

For the answers to some faq on racing gasoline go to www.tgill.com/racing/faq.htm also www.dragracingpinoy.com/tech_faq.html (question titled How Much Octane?) for some comments by Tim Wusz who (due to mergers and acquisitions) now works for Phillips Petroleum. I've worked with Tim and he knows more (factual information) than anybody about racing gasoline. If you're really sincere about learning the reality of gasoline performance his email address is twusz@ppco.com. He can probably steer you to some factual literature.

Bob P.

Thank you for the info. I wasn't trying to create a pissing match. I should have said: "Its probably your imagination." I just don't understand why people want to argue against facts. I bet you could never guess I'm an engineer.

Here is a quote from the third web site:

Quote

OCTANE REQUIREMENT
The octane requirement of an engine in a vehicle can be measured on a chassis dynamometer with a standard series of reference fuels. Racers are not expected to conduct these tests but must be able to recognize when they need a higher-octane number gasoline. Keep in mind that higher octane does not mean more power unless your engine is experiencing detonation. If racers are not sure if detonation exists, try a higher octane gasoline and see if their speeds and e.t.s improve. If they do improve, probably the engine was experiencing detonation.

i posted this morning, then could not find this thread until now. There are enough variables in drag racing that i can' t compare the difference in octane and performance in my car. I do jet up one size in the winter, just on theory, i guess.

The Hot Rodding article was done on an engine dyno, pretty stout 340, it put out about 400 hp or so. They ran octane boosters, too. All i know is that i used to believe rather naively that race gas burned slower, or some such thing. Performance improvements can certainly depend on complex things like combustion chamber characteristics, and so on. I am well aware that comparing the Mopar to my Windsor based motor could be a far streatch, too.

But i did decide that i would not advance my timing just because i put in some "race gas." In this Mopar, power fell off abit as they added more advance.

I can tell a difference in drivability, not necessarily power, (because i think you have to increase power by about 10% to tell by the seat of one's pants), when the weather conditions are different, and in some brands of gas. Drivability i can tell easily, as i drive my car every day, in every weather. My car runs much better on "summer gas". Power, i can't say. I run race gas on all track and road course events, to reduce engine detonation risk. Not because i am good enough to use my car's power anyway. But at about 55 quarter mile runs in my car, i am indeed getting pretty consistent, proud to now run a very consistent RT of .65.

Perhaps a fuel's power and drivability might have a lot more to do with variables than just octane. Beats me.

You guys do yourself a favor an save some major bucks by
adding 6 ounces of cheap laquer thinner to a every gallon
of gas. Now go see what happens. I read a big thing about
this last year and I was sceptical so I asked a good friend
of mine who holds 187 fuel & oil improvement patents. He
just retired from Amoco. He also owns a new
Mustang cobra. He still has the ability to test his fuel octanes
and uses laquer thinner to boost the octane. It's actually
the tolulene in the thinner that does the trick. He advises to
stay away from tolulene by it's self as it is some pretty nasty
stuff on the skin . He worked it out to no more than
eight ounces to a gallon of 87 octane. I stay with six.

Happy motoring !:3DSMILE:

Hersh:)

It's April 3, so you must be serious...
 

Hersh,
OK, what difference does the laquer thinner make?

Laquer Thinner
 

If you use laquer thinner, just be sure to read the label and get thinner with toluene...some brands use other stuff, and stuff that's not so good for your motor. Maybe a better way to do it is to buy pure Xylene (try a Sherwin Williams paint store, but at $26 for 5 gallons it isn't cheap). Toluene has an octane rating of 114, Xylene has a 117 octane rating. Also, Xylene is one of the ingredients commonly used in octane boosters and injector/carb cleaners.
Check out this website for some interesting comments:
http://www.vtr.org/maintain/gasoline-octane.html

The difference is really obvious to me. I know my engine
runs much better with it. I can feel the power increase.
I had two gallons of thinner on the shelf and gave it a
try about 6 months ago. I don't do it on every tank but
when I do I can really tell the difference. One thing I
did was to take a spin and shut the motor down while at
6000 RPMs. Then I coast up to my driveway and pull the
plugs. They were all the perfect chocolate color indicating a
clean burn. I did this without the thinner and the plugs
were slightly blacker. Another indication is that I
have a laptop connection to my fuel and timing and I have to
reset the idle fuel lower. The timing has stayed the same.
I also set the Global fuel 2% less. Everytime I use the thinner I
switch to this saved setting on the computor.

Hersh:)