engineers help! need info on octane boost
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Burning Brakes
Joined: Oct 1999
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From: meraux louisiana
engineers help! need info on octane boost
as i worked in an oil refinery for 26 years i watched how carefully gasoline was blended from many different products in order to reach the required octane. after lead was wisely banned i saw toluene, mmt, mtbe, etc being used to increase octane ratings. the premium gasoline in my area is 93 octane. the question in my mind is what is the maximum octane rating that our corvette engine is designed for to reach the highest horsepower? since our cars have an electronic knock sensor and are designed to increase timing to the point where knock begins i know the higher the octane the faster it becomes. if i use a commercial octane booster it only raises the rating maybe 2points which is to say from 93 to 93.2. even then i can tell from the seat of my pants that my engine becomes more powerful. are commercial octane boost harmful to my engine. dont wont to hurt my baby but it jumps like a scared frog now. before it just jumped like a frog. :hurray: :D andy
Melting Slicks
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From: kansas city MO
Re: engineers help! need info on octane boost (2000 green hornet)
93 is all you'll ever need in a N/A car w/ stock CR
I'm boosted & can't even find 93 oct. here. 92 is all we got & even that is hard to find.
I mix mine w/ 10 % Toluene.
I'm boosted & can't even find 93 oct. here. 92 is all we got & even that is hard to find.
I mix mine w/ 10 % Toluene.
Le Mans Master
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From: A FEW CLICKS NORTH OF THE CANAL
Re: engineers help! need info on octane boost (boblackhardtop)
I wish we could get 93:sad: I live in the land of the tree huggers and you can only get 91 :banghead: :skep:
Le Mans Master
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From: Fort Worth Texas
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Re: engineers help! need info on octane boost (2000 green hornet)
Hornet, as im sure you know, octane rating does not produce more power because of a higher number, and is simply a rating of a fuel not to combust under heat and pressure before the spark ignites it.
Too much octane rating when not needed, can actually act as timing retard, because of the burn rate of the fuel slows as you go up in octane rating.
I've seen hundreds of readouts where there is no knock retard through the WOT, RPM range, when using 92 and even 91 octane. I have seen many with KR, even when adding 100+ octane. This is usually due to some other issue, such as carbon building in the chamber, a rattle in the drivetrain, faulty or too sensistive knock sensors, etc.
With that said. 91-93 Octane is sufficient enough on a otherwise stock compression ratio with respect compression ratio and heat requirements. But as said, there can be other contributing factors that creat KR that increasing octane rating isnt going to help, and can actually be detrimental if taken too far.
[Modified by kewlbrz, 10:29 AM 1/12/2003]
Too much octane rating when not needed, can actually act as timing retard, because of the burn rate of the fuel slows as you go up in octane rating.
I've seen hundreds of readouts where there is no knock retard through the WOT, RPM range, when using 92 and even 91 octane. I have seen many with KR, even when adding 100+ octane. This is usually due to some other issue, such as carbon building in the chamber, a rattle in the drivetrain, faulty or too sensistive knock sensors, etc.
With that said. 91-93 Octane is sufficient enough on a otherwise stock compression ratio with respect compression ratio and heat requirements. But as said, there can be other contributing factors that creat KR that increasing octane rating isnt going to help, and can actually be detrimental if taken too far.
[Modified by kewlbrz, 10:29 AM 1/12/2003]
Drifting
Joined: Feb 1999
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From: Post Falls ID
Re: engineers help! need info on octane boost (kewlbrz)
Additionally, if I remember correctly, octane boosters with MMT will void your warranty. Many if not most boosters contain MMT. Any gains felt are probably the opposite end of SOPT, "BTEP" (Between The Ears Performance) JMHO
If you really want to increase Octane, add 10% (10:1 ratio) Racing Fuel (110 Octane) to your tank, now you'll have 94.5.
If you really want to increase Octane, add 10% (10:1 ratio) Racing Fuel (110 Octane) to your tank, now you'll have 94.5.
Safety Car
Joined: Sep 2001
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From: Wilmington NC
Re: engineers help! need info on octane boost (2000 green hornet)
as i worked in an oil refinery for 26 years i watched how carefully gasoline was blended from many different products in order to reach the required octane. after lead was wisely banned i saw toluene, mmt, mtbe, etc being used to increase octane ratings. the premium gasoline in my area is 93 octane. the question in my mind is what is the maximum octane rating that our corvette engine is designed for to reach the highest horsepower? since our cars have an electronic knock sensor and are designed to increase timing to the point where knock begins i know the higher the octane the faster it becomes. if i use a commercial octane booster it only raises the rating maybe 2points which is to say from 93 to 93.2. even then i can tell from the seat of my pants that my engine becomes more powerful. are commercial octane boost harmful to my engine. dont wont to hurt my baby but it jumps like a scared frog now. before it just jumped like a frog. :hurray: :D andy
After watching lots and lots of C5 dyno runs I can say I have never seen a car with decent gasoline go into knock detected retard. That's not to say it doesn't happen but I don't believe it is going to happen if you get a decent fill up of 93 octane. As far as octane boosters you add from a can. IMO they are a total waste of money. If your car doesn't knock extra octane will do nothing but add deposits.
[Modified by Richin Chicago, 11:42 AM 1/12/2003]
Le Mans Master
Joined: Oct 2001
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From: Southern California
Re: engineers help! need info on octane boost (RHILL)
I wish we could get 93:sad: I live in the land of the tree huggers and you can only get 91 :banghead: :skep:
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Racer
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From: mississauga ont.
Re: engineers help! need info on octane boost (RWhite)
i run only sunoco 94 octane. I notice a big difference if all I can find is 91.
My friend runs a mixture of 94 with race fuel when he is spraying(that's pretty much all the time) and no problems!
My friend runs a mixture of 94 with race fuel when he is spraying(that's pretty much all the time) and no problems!
Melting Slicks
Joined: Jan 2001
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From: Aloha, Oregon
Re: engineers help! need info on octane boost (topgun)
Additionally, if I remember correctly, octane boosters with MMT will void your warranty. Many if not most boosters contain MMT.
Kwlbrz hit the nail on the head in his post here. Octane is only its ability to resist knock. nothing to do with more power. too much octane vs the engine's real need WILL hurt performance due to flame burn rate and propagation.
If you do discover you can benefit from increased octane, use Toluene or Xylene, both of which have an octane rating of 116-117. just do the math to figure out your ratio to achieve the final octane you require. Again, i caution about increasing your octane a whole bunch without knowing your needs. If you've modified your car (blower, increased static CR, heavy nitrous use) and you know you need more octane to combat knock, experiment with ratio's of pump gas and Toluene until your knock goes away, then maybe go one more point above that. I can purchase a 55 gal drum of Toluene here in Oregon for ~$2 a gal. A 5 gallon drum from a paint store goes for $35 ($7/gal).
[Modified by rwj383, 10:53 PM 1/12/2003]
Safety Car
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From: Insert Wittty Comment here
Re: engineers help! need info on octane boost (Mitch Alsup)
Safety Car
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From: Ocean Springs MS
Re: engineers help! need info on octane boost (2000 green hornet)
the question in my mind is what is the maximum octane rating that our corvette engine is designed for to reach the highest horsepower? since our cars have an electronic knock sensor and are designed to increase timing to the point where knock begins i know the higher the octane the faster it becomes. if i use a commercial octane booster it only raises the rating maybe 2points which is to say from 93 to 93.2. even then i can tell from the seat of my pants that my engine becomes more powerful. are commercial octane boost harmful to my engine. andy
IMHO :yesnod:
Safety Car
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From: Insert Wittty Comment here
Re: engineers help! need info on octane boost (fdxpilot)
The engine will only retard timing when it detects knock. Also refered to as KR. You can look at this with ATAP or EASE. Toluene can boost your octane from 93 to 96 pretty easily. ! gallon of Toluene or Xylene to 5 gallons of 93. Or you can get 104 race gas for $4.75/gallon...
Your factory timing is set already. Even if you have 104 octane, it won't go pasts its maximum without a programming change (diablo or ls1edit). Your factory program is optimized for regular gas...
As for octane boost. Make it yourself and save a lot of money. Most octane boost is simply a small bottle of Toluene marked up 500-1000% or a small portion of MMT.
Your factory timing is set already. Even if you have 104 octane, it won't go pasts its maximum without a programming change (diablo or ls1edit). Your factory program is optimized for regular gas...
As for octane boost. Make it yourself and save a lot of money. Most octane boost is simply a small bottle of Toluene marked up 500-1000% or a small portion of MMT.
Race Director
Joined: Jul 2002
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From: Sterling VA
Re: engineers help! need info on octane boost (J-Rod)
Well, I had been running 93 octane since I first got my '01 vert in July '02, but when I mashed the gas it would ping. Switched to Sunoco 94 octane recently, now no ping.
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
Le Mans Master
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From: Fort Worth Texas
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Re: engineers help! need info on octane boost (bierbelly)
Well, I had been running 93 octane since I first got my '01 vert in July '02, but when I mashed the gas it would ping. Switched to Sunoco 94 octane recently, now no ping.
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
Race Director
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From: Sterling VA
Re: engineers help! need info on octane boost (kewlbrz)
Well, I had been running 93 octane since I first got my '01 vert in July '02, but when I mashed the gas it would ping. Switched to Sunoco 94 octane recently, now no ping.
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
I highly doubt that 1 increase in octane would fix a consistant pinging problem when going to WOT. The more likely reason is that the quality of the fuel is better then the the quality you were using before (not the difference in octane). Just my guess. :cheers:
Toluene or mixed xylenes are probably the cheapest way to boost octane. Toluene is frequently used as paint remover--so don't get it on your paint, needless to say.
I highly doubt that 1 increase in octane would fix a consistant pinging problem when going to WOT. The more likely reason is that the quality of the fuel is better then the the quality you were using before (not the difference in octane). Just my guess. :cheers:
