Racing Fuels

[cars4me89]

In my nearly bone stock supra, i usually put shell 93 octane fuel but was wondering what 100+ octane fuel would hurt in my car if anything.

[ravenmaster]

i WOULD not SUGGEST USING THAT ADDITIVE STUFF BUT IF YOUR TALKING ABOUT THE STUFF THEY SELL AT SOME GAS STATIONS...WE HAVE ONE HERE IN MY TOWN THAT SELLS 100 OCTANE I USUALLY UT A TANK OF IT IN MY CAR EVERY MONTH. hIGHER OCTANE BURNS HOTTER WHICH HELPS CLEAN OUT CARBONS AND OTHER BAD STUFF IN YOUR ENGINE. bUT NO IT SHOULDN'T HURT YOUR CAR AT ALL.

[volto]

Thats the same thing the addatives do. The ones ive used only boost octane, they dont contain anything else. (at least i hope not)

[rnoswal]

Actually, the fuel buns slower and cooler. The extra lead or chemical is put in to the hight octane fuel to help it avoid pre-ignition. The only way to help that is to slow the burn down which means a cooler burn and more controlled to fight against detonation.

Usually the additives help disolve the particles to clean out the valves and injectors, but ideally you want a low enough octane fuel that burns fast and gives you the most power without detonation. You can adjust ignition timing to get the best power curve and let you know if you are detonating at any point, When that happenes, you get a hotter burn, but an uncontrollable burn, Many times there are two or more flamefronts and when they meet it is heard and a nice pinging sound and very detremental to the combustion chamber.

Put it on a chassis dyno, ( God I Wish I had one! No one hear does in this neighborhood and it wouldn'd be long before it was paid for and the drivers would get such huge benefits from this. The higher the octane with everything else being the same will mean a less powerful engine.\

Russ

[volto]

I thought most toyotas ask for mid grade or premium gas?

[Supra2NR]

what would happen if u filled up ur tank with racing gas rating 103 octane?

if not what is a good ration between the 93octane : 103octane

cuz on racing nights i put
1 gallon of 103 per 3 gallons of 93

[ravenmaster]

Originally Posted by rnoswal

Actually, the fuel buns slower and cooler. The extra lead or chemical is put in to the hight octane fuel to help it avoid pre-ignition. The only way to help that is to slow the burn down which means a cooler burn and more controlled to fight against detonation.

Usually the additives help disolve the particles to clean out the valves and injectors, but ideally you want a low enough octane fuel that burns fast and gives you the most power without detonation. You can adjust ignition timing to get the best power curve and let you know if you are detonating at any point, When that happenes, you get a hotter burn, but an uncontrollable burn, Many times there are two or more flamefronts and when they meet it is heard and a nice pinging sound and very detremental to the combustion chamber.

Put it on a chassis dyno, ( God I Wish I had one! No one hear does in this neighborhood and it wouldn'd be long before it was paid for and the drivers would get such huge benefits from this. The higher the octane with everything else being the same will mean a less powerful engine.\

Russ

Your right on most other stuff except the slower cooler burn. That is a myth I have seen on many a website and told around but what I learned in mechanics school (i took one so i know what it is I am looking at, before hand I would look at an engine and be like uhhh where is the intake again?" Anyway your wrong about that. HIGHER OCTANE= Higher BURN. Its designed that way for racing vehicles. Don't want to get carbon choke in the middle of a race do you?

[ZauggIt1]

Its actually higher the octane the cleaner the burn and the burn last longer, why do you think you get better gas mileage with higher octane?? becuase it takes longer to burn which in fact is better for the motor, if it burns longer, it burns purely, which is cleaner. SO yes, it is better for the motor to be runing higher octane, the only thing is that the timing might have to be adjusted for it, it is going to have to be advanced a couple of degrees for it to run at its fullest. I dont know how much the computers advance and retard the timeing, i dont think it will if you puter higher octane in it. Hope this helps.

[cars4me89]

I also think that you are correct that higher octane burns hotter.. i just wanted to know about that retard and timing stuff. so if i go to sp, i live bout 30 min away from them, and tell them i want it set up for racing fuel 100+ octane.. they could "tune" the ignition for that?

[ravenmaster]

Highly doubtful a gas station would do it. Plus in all honesty The adjustments are so miniscule that its pointless if your only gunna run a tank of it every once in awhile if your going to use it all the time though...in that case I suggest use your best judgement. HEED THIS ADVICE THOUGH: MEsS WITH THE STOCK AFM AS A LAST RESORT!!!
Oh and toyota told me today that recommended current fuel for "o-ptimum" efficiency, for the 7MGE and 7MGTE whether newer, older or rebuilt is mid grade 89.
(Use the mid gade for your location, my 89 is based off the following fuel availabilities: 87 Octane[LOW] 89 Octane[Mid Range] 91 Octane[Performance].)
Anyway use whatever your comfortable with I have always used 89 on my 87 N/A but if your turbo i suggest using your bat rope. :-) I mean errr the highest NON RACE octane available (i.e 91)