Higher Octane Maps

RacerXS · 08-11-2005, 06:53 PM

I was wondering if anyone has an idea how COBB changes their maps for higher octane. Do they simply advance timing in certain areas? How much I wonder for each point of octane raised, is there a rule of thumb?

cnstman · 08-11-2005, 07:47 PM

do you mean their AP maps? if so, they can't change much, there is only a gain of 5hp or so. no rule of thumb for different fuel octane that i have found, each car / brand of fuel / etc is different.

RacerXS · 08-12-2005, 04:58 AM

I just want to get an idea what they or any other good tuner does for increased Octane. Increased timing; if you have done it, how much for what octane?
Are there any other maps we should be looking at?

daemon · 08-12-2005, 08:07 AM

Three options. Increase boost. Probably not feasible on stock turbo as it is so short of breath up top anyway. Add a touch of timing. Possible, but I'd want to have at least some sort of dyno to back it up and make sure the increase in timing was resulting in an actually increasing power. Though if you dynamic advance is at max, you could probably bump timing a little and let the learning keep it safe. There comes a point where increasing timing won't add power. As a side note, I've always wondered if the ECU learning takes that into account at all. Probably not. If it doesn't see knock it'll keep pushing advance past MBT I'd guess if the KC maps allow it. Third option is to lean out the AFR a bit. I think that would be my choice without a dyno. But what do I know, I'm fairly new at this myself.

Of course, you have to take your current tune into account when making this decision. Were are your boost, timing, and AFRs already. If you pushed one as far as you think is safe, maybe try pushing another component a little. No matter what, do everything in small steps.

RacerXS · 08-12-2005, 09:49 AM

Quote:

Originally Posted by daemon

Three options. Increase boost. Probably not feasible on stock turbo as it is so short of breath up top anyway. Add a touch of timing. Possible, but I'd want to have at least some sort of dyno to back it up and make sure the increase in timing was resulting in an actually increasing power. Though if you dynamic advance is at max, you could probably bump timing a little and let the learning keep it safe. There comes a point where increasing timing won't add power. As a side note, I've always wondered if the ECU learning takes that into account at all. Probably not. If it doesn't see knock it'll keep pushing advance past MBT I'd guess if the KC maps allow it. Third option is to lean out the AFR a bit. I think that would be my choice without a dyno. But what do I know, I'm fairly new at this myself.

Of course, you have to take your current tune into account when making this decision. Were are your boost, timing, and AFRs already. If you pushed one as far as you think is safe, maybe try pushing another component a little. No matter what, do everything in small steps.

This is the kind of answer I was looking for. Thanks.

08-11-2005, 06:53 PM	#1
RacerXS S204 Racer Car: 05' Sti Black Fav Mod: Dyslexia Location: Central, NJ Posts: 3,362 Join Date: Oct 2004 Trader Rating: (13)	Higher Octane Maps I was wondering if anyone has an idea how COBB changes their maps for higher octane. Do they simply advance timing in certain areas? How much I wonder for each point of octane raised, is there a rule of thumb? This ad is not endorsed by this member. Please register or login to hide this ad.

08-12-2005, 08:07 AM	#4
daemon The Next Petter Solberg Car: 2004 STi Location: Florida Posts: 865 Join Date: Feb 2004 Trader Rating: (0)	Three options. Increase boost. Probably not feasible on stock turbo as it is so short of breath up top anyway. Add a touch of timing. Possible, but I'd want to have at least some sort of dyno to back it up and make sure the increase in timing was resulting in an actually increasing power. Though if you dynamic advance is at max, you could probably bump timing a little and let the learning keep it safe. There comes a point where increasing timing won't add power. As a side note, I've always wondered if the ECU learning takes that into account at all. Probably not. If it doesn't see knock it'll keep pushing advance past MBT I'd guess if the KC maps allow it. Third option is to lean out the AFR a bit. I think that would be my choice without a dyno. But what do I know, I'm fairly new at this myself. Of course, you have to take your current tune into account when making this decision. Were are your boost, timing, and AFRs already. If you pushed one as far as you think is safe, maybe try pushing another component a little. No matter what, do everything in small steps. Last edited by daemon : 08-12-2005 at 08:10 AM.

08-11-2005, 07:47 PM	#2
cnstman Spec C Club Car: 04 STi Fav Mod: GT-35R Location: Colorado Springs Posts: 1,326 Join Date: Jan 2003 Trader Rating: (2)	do you mean their AP maps? if so, they can't change much, there is only a gain of 5hp or so. no rule of thumb for different fuel octane that i have found, each car / brand of fuel / etc is different.

08-12-2005, 04:58 AM	#3
RacerXS S204 Racer Car: 05' Sti Black Fav Mod: Dyslexia Location: Central, NJ Posts: 3,362 Join Date: Oct 2004 Trader Rating: (13)	I just want to get an idea what they or any other good tuner does for increased Octane. Increased timing; if you have done it, how much for what octane? Are there any other maps we should be looking at?