If I were to put a few gallons of 93 octane gas in my near stock 99 T/A and follow that by a gallon or so of high octane race fuel <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" /> at a local gas station, how would that affect my engine? It'd run hotter, but what else would happen? Thanks

 

Hey,Riceburner come up Audio Advisors on thursday nights look for a Blus Ta and hang out before we get overrun with "rice"

 

Make sure it's unleaded race fuel. If it's leaded it won't make your cats and O2 sensors happy. Running leaded fuel a few times won't exactly kill the cats right off the bat but it will sooner or later. If you ain't got cats, never mind. BTW, the only way the higher octane will help make more power is if you have some knock retard due to detonation. JMO

 

At the track, with 1/4 tank of 93, or less add a gal. or 2 of 103 unleaded VP racegas, or 104 unleaded Sunoco racegas. Your car will like it on the top end. On the street, stick w/93 or 4 and don't waste your money on racegas. WJ. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

guiness-
i was going to head out there tonight, but i didn't get out of work until 10 30.I have a friend who goes out there, calls it 'car club'. I called him to tell him i was on my way but he said the cops came. what mods do you have done to ur T/A?

 

It's been my experience that my car has ran slower using race gas. Runs best on good old 93 octane.

 

check this link out:
http://auto.howstuffworks.com/framed.../racefuel.html

It's all about race fuels... but, I'm preety sure you can only get up to 100 octane that's unleaded (therefore purely octane molecules)

The lead that's added in race gas allows more octane molecules to be "chained" together thereby increasing its resistance to predetonation....

just my $.02

<small>[ February 14, 2003, 05:08 PM: Message edited by: get_sum ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Rice Burner:
<strong> If I were to put a few gallons of 93 octane gas in my near stock 99 T/A and follow that by a gallon or so of high octane race fuel <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" /> at a local gas station, how would that affect my engine? It'd run hotter, but what else would happen? Thanks </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">A few points, I hope I am correct.
1. in a very basic way, your car "learns" what octane you have put in it. Every time you add (refill) more than 20% tank of gas, the PCM resets the learning process to learn your new tank of gas. If you have been driving on 93 and you add a gallon of 105 unleaded, you get nothing more than what you had. Same average timing advance you had before.
2. If you add 3 gallons of 105 your car will reset this table (allowing more timing advance for a short time) and learn the new slightly higher octane. You can actually feel this performance when you fill up for a short period of time. As your car learns, it adjust the timing back down as neccessary.
3. adding three gallons of 105 to three gallons of 93, makes ~98 octane fuel assuming it sloshes around good. Your car will learn that it has a 98 octane fuel supply.
4. I go to the track with the Check Guages light on and buy three gallons of 105 unleaded. How much does my $15 get me? About a .1 to .2 in the quarter if the weather is good and I can advance my WOT spark and decrease the enrichment. Its really not worth it and I started running 93 again. If I made a couple 12.01 runs, I'd buy the good gas for $5 a gallon at the track.

Basically your car runs best with 0.0 KR. You can do that with 93 as easily as 105. If your car sees no KR it will continue to advance timing at WOT. KR in a slightly modded car is usually do to noises and vibrations other than pre-detonation. These issues need to be dealt with before octane.

Now, if you're running a race engine that is high compression without all that shitty PCM stuff and sensors, then **** it, put racegas in and run like Hell.

<small>[ February 15, 2003, 09:23 PM: Message edited by: 2000WhiteZ28 ]</small>

 

Thanks for the input everyone. I'll let you know how I make out in a week or so. thanks again

 

octane is not a horsepower increaser. the octane rating is just the fuels ability to resist detonation, it won't run hotter, maybe a little cleaner. if you add another type of fuel like a little nitromethane, you will get the hp you want. i mean the nitromethane in NOS octane boosters, it won't make ten, but a friend saw 3 at the wheels on back to back passes, wether that was the fuel?? who knows but it happened.

 

yup. If your not having detonation problems, higher octane won't help. Most of our cars run very rich..

 

from what i understand you car won't adjust any for better gas, it is designed for 92 or so and will adjust your timing down for worse gas from there if it needs to. but it doesn't have tables designed for gas any better than 92. lots of variables here so 93 might help if you have any KR but 100 or 104 wont help at all since there is no programing for it.