Whats The Purpose...
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From: Long Island
Whats The Purpose...
Why do people tune their car to accept 93 octane with only 2.4 Manifold,Exhaust,Header,Intake,Downpipe and Underdrive Pulley? Is their really a difference of switching to a higher octane with these mods?
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From: Livonia, MI
Actually no, this is incorrect. The octane rating is actually resistance to detonation. The higher the octane rating, the less likely to burn. But as you increase timing, boost, and compression ratio, the cylinder pressures increase as well as temperatures, which casue preignition. So the advantage to the higher octane is that you can tune your car for maximuim power without preignition.
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From: Michigan
Actually no, this is incorrect. The octane rating is actually resistance to burn. The higher the octane rating, the less likely to burn. But as you increase timing, boost, and compression ratio, the cylinder pressures increase as well as temperatures, which casue preignition. So the advantage to the higher octane is that you can tune your car for maximuim power without preignition.
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From: Long Island, NY
Actually no, this is incorrect. The octane rating is actually resistance to burn. The higher the octane rating, the less likely to burn. But as you increase timing, boost, and compression ratio, the cylinder pressures increase as well as temperatures, which casue preignition. So the advantage to the higher octane is that you can tune your car for maximuim power without preignition.
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From: "Central", PA
Actually no, this is incorrect. The octane rating is actually resistance to detonation. The higher the octane rating, the less likely to burn. But as you increase timing, boost, and compression ratio, the cylinder pressures increase as well as temperatures, which casue preignition. So the advantage to the higher octane is that you can tune your car for maximuim power without preignition.
that's why i didn't write a paragraph... i just knew if tuned properly, it was better for power.
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From: Baltimore
Actually no, this is incorrect. The octane rating is actually resistance to detonation. The higher the octane rating, the less likely to burn. But as you increase timing, boost, and compression ratio, the cylinder pressures increase as well as temperatures, which casue preignition. So the advantage to the higher octane is that you can tune your car for maximuim power without preignition.
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From: "Central", PA
hope you weren't refering to me.
i wasn't that far off with my answer. I said it burns more efficiently. He corrected the technicalities in my post and provided a more detailed description of the combustion process.
and i'm an ass because of douchebag newbs like you.
i wasn't that far off with my answer. I said it burns more efficiently. He corrected the technicalities in my post and provided a more detailed description of the combustion process.
and i'm an ass because of douchebag newbs like you.
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From: Livonia, MI
Back when we were tuning the spark/fuel maps for the OEMs on the dyno we would run 91 RON (research octane method. The pump octane rating most people know is an average of the RON and MON methods. You will see a R+M/2 on the octane sticker on the pump, this is what that means). We would tune with the 91 RON, then go back and tune with 85 for the people that didnt run premium
usually. the difference between 87 octane and 91 octane at the pump is only a $30 fill up for 87, or a $32 fill up for 91....does the extra $2 matter to you? or is $2 worth the extra horsepower? Its easily worth it to me
Last edited by HunterKiller89; Apr 4, 2009 at 04:05 PM.
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From: Vancouver, WA
two fuel tables, one for high octane, one for low. lets say you get some gas, upon startup it will attempt to run the high octane table w/ advanced timing and will back it down. Stock the l61's don't have anything set to really get the most out of high octane, probably why my stock cobalt dyno vs stock w/tune was only a 4hp increase. you could see the advanced timing and adjusted fuel table at work in combination with the higher octane fuel.
One cool cool thing about the tune and computer is that if we enter a great depression, we can still run regular. at least those of us with nothing crazy done(turbo, sc)
i forget how many degrees he was able to advance my timing, i think if was more than 3 degrees though lol.
you just described the very thing our l61 powered cobalts do as well. i know 07+ has this, and pretty sure about previous years as well.
two fuel tables, one for high octane, one for low. lets say you get some gas, upon startup it will attempt to run the high octane table w/ advanced timing and will back it down. Stock the l61's don't have anything set to really get the most out of high octane, probably why my stock cobalt dyno vs stock w/tune was only a 4hp increase. you could see the advanced timing and adjusted fuel table at work in combination with the higher octane fuel.
One cool cool thing about the tune and computer is that if we enter a great depression, we can still run regular. at least those of us with nothing crazy done(turbo, sc)
i forget how many degrees he was able to advance my timing, i think if was more than 3 degrees though lol.
two fuel tables, one for high octane, one for low. lets say you get some gas, upon startup it will attempt to run the high octane table w/ advanced timing and will back it down. Stock the l61's don't have anything set to really get the most out of high octane, probably why my stock cobalt dyno vs stock w/tune was only a 4hp increase. you could see the advanced timing and adjusted fuel table at work in combination with the higher octane fuel.
One cool cool thing about the tune and computer is that if we enter a great depression, we can still run regular. at least those of us with nothing crazy done(turbo, sc)
i forget how many degrees he was able to advance my timing, i think if was more than 3 degrees though lol.
you just described the very thing our l61 powered cobalts do as well. i know 07+ has this, and pretty sure about previous years as well.
two fuel tables, one for high octane, one for low. lets say you get some gas, upon startup it will attempt to run the high octane table w/ advanced timing and will back it down. Stock the l61's don't have anything set to really get the most out of high octane, probably why my stock cobalt dyno vs stock w/tune was only a 4hp increase. you could see the advanced timing and adjusted fuel table at work in combination with the higher octane fuel.
One cool cool thing about the tune and computer is that if we enter a great depression, we can still run regular. at least those of us with nothing crazy done(turbo, sc)
i forget how many degrees he was able to advance my timing, i think if was more than 3 degrees though lol.
two fuel tables, one for high octane, one for low. lets say you get some gas, upon startup it will attempt to run the high octane table w/ advanced timing and will back it down. Stock the l61's don't have anything set to really get the most out of high octane, probably why my stock cobalt dyno vs stock w/tune was only a 4hp increase. you could see the advanced timing and adjusted fuel table at work in combination with the higher octane fuel.
One cool cool thing about the tune and computer is that if we enter a great depression, we can still run regular. at least those of us with nothing crazy done(turbo, sc)
i forget how many degrees he was able to advance my timing, i think if was more than 3 degrees though lol.
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From: Long Island
okay now this may be a stupid question but lets say i get the 93 octane tune, and at a gas station with only 91 octane can I use that, or would I have to add a bottle of octane boost?
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From: Blaine, MN
^I am not going to say I know the answer to that, but I would say that it will run fine. I was going to ask if you're tuned for 91 or higher and go back to 87 if there will be any issues, but I realized that you would only have a problem (or possibly have a problem) if you had F/I, not N/A (again, not 100% sure, but pretty sure).
Also, if I understand correctly, Octane Booster is a waste of money, you're only boosting it by points (correct me if I'm wrong as I really don't know much about this either, just read something along those lines).
Definitely not a stupid question as it would be good for a lot of people to know.
Also, if I understand correctly, Octane Booster is a waste of money, you're only boosting it by points (correct me if I'm wrong as I really don't know much about this either, just read something along those lines).
Definitely not a stupid question as it would be good for a lot of people to know.