How much Octane is TOO much?
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From: Raleigh, NC
How much Octane is TOO much? If it is unleaded gas, can you put too high an octane gas in that it hurts your performance or your car?
I usually put in 100 or 104 if I want high octane. But I've seen unleaded 108 and even octane rating in the 100-teens at the track. Admittedly, there's likely a point where it no longer helps. But, is there a point that it actually HURTS?
Thanks!
I usually put in 100 or 104 if I want high octane. But I've seen unleaded 108 and even octane rating in the 100-teens at the track. Admittedly, there's likely a point where it no longer helps. But, is there a point that it actually HURTS?
Thanks!
Re: How much Octane is TOO much? Yes
Unless you are upping the timing or compression to require the octane you'll be pushing the combustion event too far past TDC. That results in incomplete combustion and loss of cylinder pressure. And thus a loss of power.
You can have too much octane <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Unless you are upping the timing or compression to require the octane you'll be pushing the combustion event too far past TDC. That results in incomplete combustion and loss of cylinder pressure. And thus a loss of power.
You can have too much octane <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
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From: Raleigh, NC
Re: How much Octane is TOO much? Thanks! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Your comment being said, does anyone care to speculate how high is too much? I'd think 104 is fine. How about 108? 116? Is there anyone who has experimented with different high-level unleaded octane fuel and found the down point?
Your comment being said, does anyone care to speculate how high is too much? I'd think 104 is fine. How about 108? 116? Is there anyone who has experimented with different high-level unleaded octane fuel and found the down point?
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Re: How much Octane is TOO much? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>You can have too much octane <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sure, but YOU can't, canya? Hmm? Hmmm?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Black LS1 T/A:
<strong>Your comment being said, does anyone care to speculate how high is too much? I'd think 104 is fine. How about 108? 116? Is there anyone who has experimented with different high-level unleaded octane fuel and found the down point?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Check your KR. I leaned on my combo with the MAFT more than I would EVER have expected with just 93. It took a seriously lean A/F to produce some KR. Then I just knocked it back. The thing is just an animal now.
IMO, if your not seeing KR on 93, you're just wasting your money...
SC
<small>[ May 08, 2002, 01:38 PM: Message edited by: SS00Blue ]</small>
<strong>You can have too much octane <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sure, but YOU can't, canya? Hmm? Hmmm?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Black LS1 T/A:
<strong>Your comment being said, does anyone care to speculate how high is too much? I'd think 104 is fine. How about 108? 116? Is there anyone who has experimented with different high-level unleaded octane fuel and found the down point?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Check your KR. I leaned on my combo with the MAFT more than I would EVER have expected with just 93. It took a seriously lean A/F to produce some KR. Then I just knocked it back. The thing is just an animal now.
IMO, if your not seeing KR on 93, you're just wasting your money...
SC
<small>[ May 08, 2002, 01:38 PM: Message edited by: SS00Blue ]</small>
Re: How much Octane is TOO much? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by SS00Blue:
<strong>Sure, but YOU can't, canya? Hmm? Hmmm?
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Just fill it with C16 and crank the **** till the heads lift. Than back it off half a turn <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />
You think i'm joking, i know you do <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
<strong>Sure, but YOU can't, canya? Hmm? Hmmm?
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Just fill it with C16 and crank the **** till the heads lift. Than back it off half a turn <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />
You think i'm joking, i know you do <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Re: How much Octane is TOO much? it depends. Effective compression and advance dictate the required octane
I ran 8 to 9 psi on 94 pump gas, making about 500RWHP.
leaving the advance unchanged, it needed to run 100 ocatne to get to 10+ psi and near 600 RWHP.
Too many ***** that can be turned just give a simple yes/no answer or an octane requirement.
Fix all other quantities, and then determine the octane needed
check this out for an idea
http://www.turbofast.com.au/TFcompB.html
I ran 8 to 9 psi on 94 pump gas, making about 500RWHP.
leaving the advance unchanged, it needed to run 100 ocatne to get to 10+ psi and near 600 RWHP.
Too many ***** that can be turned just give a simple yes/no answer or an octane requirement.
Fix all other quantities, and then determine the octane needed
check this out for an idea
http://www.turbofast.com.au/TFcompB.html
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Re: How much Octane is TOO much? The difference is merely in performance though. You aren't harming the engine by running excessive octane, right?
Too much timing on the other hand puts excessive stress on the wrist pins and rods.
J.
Too much timing on the other hand puts excessive stress on the wrist pins and rods.
J.
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Re: How much Octane is TOO much? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
[QBJust fill it with C16 and crank the **** till the heads lift. Than back it off half a turn
You think i'm joking, i know you do[/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope. I think I saw the indentations in your hood. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
Running too much octane doesn't damage an engine the way detonation can, but as Matt said, it retards the combustion process. Just work what you can get at the pump with the scan/atap/etc that you use, and it'll wash as you adjust. If your combo is stupid radical, the KR will show it. If not, you have more room for idiocy, or you can run that Sunoco 78 octane now... <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
SC
[QBJust fill it with C16 and crank the **** till the heads lift. Than back it off half a turn
You think i'm joking, i know you do[/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope. I think I saw the indentations in your hood. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
Running too much octane doesn't damage an engine the way detonation can, but as Matt said, it retards the combustion process. Just work what you can get at the pump with the scan/atap/etc that you use, and it'll wash as you adjust. If your combo is stupid radical, the KR will show it. If not, you have more room for idiocy, or you can run that Sunoco 78 octane now... <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
SC
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Re: How much Octane is TOO much? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Crazyquik:
<strong>The difference is merely in performance though. You aren't harming the engine by running excessive octane, right?
Too much timing on the other hand puts excessive stress on the wrist pins and rods.
J.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">too much timing can cause detonation. run just enough octane to prevent this, thats all you need. LS1 edit is s beatiful thing, have two programs one for pump gas, and one for race gas, this way you wont have to worry about seeing too much boost on the street with a 3.2 pulley, just retard some timing.
<strong>The difference is merely in performance though. You aren't harming the engine by running excessive octane, right?
Too much timing on the other hand puts excessive stress on the wrist pins and rods.
J.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">too much timing can cause detonation. run just enough octane to prevent this, thats all you need. LS1 edit is s beatiful thing, have two programs one for pump gas, and one for race gas, this way you wont have to worry about seeing too much boost on the street with a 3.2 pulley, just retard some timing.
