PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   Pontiac - Race (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=419)
-   -   Race Gas !!! (https://forums.maxperformanceinc.com/forums/showthread.php?t=415819)

LouisianaGuy 04-20-2003 08:35 PM

Ok i usually run plain old 93 Octane here in Louisiana in my TA, my question is how much of that race gas should i mix with a Tank full of Regular premium to attain the best ET possiable?
Motor is around 9 to 1.
What grade race gas should i get?? the 110 or higher?
And how much of a performance gain will the stuff really give me at the track?? i mean for like 5 bucks a gallon it better give at least a mph or two.
Mike

LouisianaGuy 04-20-2003 08:35 PM

Ok i usually run plain old 93 Octane here in Louisiana in my TA, my question is how much of that race gas should i mix with a Tank full of Regular premium to attain the best ET possiable?
Motor is around 9 to 1.
What grade race gas should i get?? the 110 or higher?
And how much of a performance gain will the stuff really give me at the track?? i mean for like 5 bucks a gallon it better give at least a mph or two.
Mike

torqjunki 04-20-2003 08:44 PM

DO NOT run race gas in that 9:1 motor http://forums.performanceyears.com/g...s/icon_mad.gif It will not run any better and will probably slow it down. Will also degrade idle quality. The high octane race gas burns slower and should only be used with high compression. http://forums.performanceyears.com/g.../icon_wink.gif

Jack Ferris 04-20-2003 09:07 PM

What T-J said......

Bartman 04-20-2003 09:30 PM

The only way it might make you run quicker is if you are running too rich as it is. Race gas weighs less than pump gas which you will need to rejet accordingly.
Contrary to what TJ said it doesn't burn slower (common misconseption). It can make you car act different because your carb isn't setup for it.
I wouldn't bother with the race gas. I have a 10 to 1 455 and it runs fine on 93 octane. I would suggest you get the gas at the same station if possible. Gasoline can vary from station to station and keeping your gas consistant is just one more way to keep your car consistant.
Bartman

Ponies run but Birds fly

LouisianaGuy 04-20-2003 11:08 PM

The how come so many people are running a mix of regular pump gas and race gas of there are no benefits to the higher octane levels?
i mean wouldnt an engine run better on say 100 total octane as opposed to 93?? i did not plan on running straight Race gas, just a mild mix to try it out, but may just stay away from the stuff after what yall have said.
Mike

PMDRACER 04-20-2003 11:35 PM

Octane is a measure of a fuel's resistance to pre-ignition (ping).

In California, you see R+M/2 on the pump. Research+Motor/2. Research is the theoretical point of detonation a fuel can take, and Motor is the number they got from their real tests. Incedentally, they use a two cylinder engine that they can change the compression ratio by screwing in or out the roof of the pistons!

While a higher octane fuel will resist pre-ignition, it also is more difficult for your ignition to fire it off. This is why some vehicles seem to "slow down with higher octane fuel".

Running higher octane fuel will do nothing for performance if your car runs fine on the cheaper stuff.

Many people confuse higher octane as meaning a more powerful fuel. Not so at all.

There is also merit to the idea of fuel being different from manufacturer to manufacturer. My '71 and my wife's new car both get better mileage from using Union 76 fuel. http://forums.performanceyears.com/g...n_confused.gif

TIGER EFI - Electronic Fuel Injection for the Traditional Pontiac Engine. [email protected]

tikiklubracing 04-21-2003 05:58 AM

This is probably useless but here goes. Here's one for ya. Reserchers and trial and error junkies (not you torq). Gas uses octane to slow burn of fuel to prevent knock. ??Any one tried Cetane, as in Diesel fuel?? Don't know anything about it, but I have questions. http://forums.performanceyears.com/g...on_biggrin.gif http://forums.performanceyears.com/g...icon_smile.gif http://forums.performanceyears.com/g.../icon_cool.gif http://forums.performanceyears.com/g.../icon_wink.gif http://forums.performanceyears.com/g.../icon_razz.gif

BIGGERISBETTER-15 yrs in NHRA tech ret. 400 .030 1977, RPM E-Take, Q-jet, 6X, TH350, 8.5 3.73 spool, 3650#, 78 Catalina, 14.50's. Check it out, www.nhra.com.

Brian Baker 04-21-2003 06:53 AM

If an engine only requires 90 octane to prevent detonation and preignition, then running 100 or 110 octane in it is not going to make it run better.

Higher octane does not equal higher horespower provided the engine's octane requirements are already being met. Having said this, 93 octane is all you'll ever need on a 9:1 engine (and you may be able to run 89 octane at the pump).

Nitromethane on the other hand is different. Becasue this fuel (which was originally used as a solvent) has oxygen bearing properties to it, the more you put in, the more power you make. This is why Top Fuel engines make the power they do, the fuel is carrying oxygen with it.

http://kurtspontiac.homestead.com/files/bbaker.jpg

Brian Baker 04-21-2003 06:54 AM

If an engine only requires 90 octane to prevent detonation and preignition, then running 100 or 110 octane in it is not going to make it run better.

Higher octane does not equal higher horespower provided the engine's octane requirements are already being met. Having said this, 93 octane is all you'll ever need on a 9:1 engine (and you may be able to run 89 octane at the pump).

Nitromethane on the other hand is different. Becasue this fuel (which was originally used as a solvent) has oxygen bearing properties to it, the more you put in, the more power you make. This is why Top Fuel engines make the power they do, the fuel is carrying oxygen with it.

http://kurtspontiac.homestead.com/files/bbaker.jpg

torqjunki 04-21-2003 10:05 AM

Before I decked my block with new combo, I had decided to run only the GOOD STUFF. The car ran like sh@#t. It stumbled, hesitated and performance seemed off, and was not responding to jet changes. Never thought about the fuel. As fate would have it, I was out street racing one weekend and ran low on fuel. I popped into the Chevron and topped off on premium. By the time I got back on the main road, the car smoothed out and ran like it had in the past.

head #96 04-21-2003 02:33 PM

Motor might not have liked the racegas, but the valveguides sure do love the lead. I sometimes will mix a couple gallons at the track to play with the timing. Hard to hear detination with open headers. Plus it smells so yummy. http://forums.performanceyears.com/g...on_biggrin.gif

Building a fast stock appearing street car.
homepage http://home.mchsi.com/~vroman6

Brinson Pachar 04-21-2003 07:10 PM

Used to run octane numbers on gasoline for a major oil company. I will tell what I know about octane. It is true the octane number relates to a fuel's ability to resist detonation under compression. Two catalysts are used to make leaded gasoline. Tel(tetraethyl-lead) for avition and tml(tetramethyl-lead) for automotive gasolines. The catalyst does indeed slow down the reaction rate of combustion. The octane you see at the pump is a combination of the reasearch method and the motor method which are both run on a single cylinder variable compression ratio engine. All octane numbers are based on a comparison between n-heptane which has a octane number of zero and iso-octane which has a octane number of 100. If you use a octane higer than what is required for your compression ratio, it could have adverse effects and slow you down. There are of course benefits to be gained from race gas if needed for your compression ratio. The quality of the feedstock used is higher than pump gas as lead will quickly reach a saturation point in gas ( aroun 4 grams/gallon) and will not raise the octane number after that. So VP and Sonoco and others must start with a higher quality fuel to gain the high octane ratings. Watch out for the games some race gas companies play though, most race fuel is rated by motor octane I believe, and some will use the reasearch number to make higher octane claims with the same fuel. Hope this helps.


All times are GMT -4. The time now is 03:01 AM.