A new analysis of Premium vs. Regular
02-23-2015, 01:32 PM
#441
Senior Moderator
Here's the REAL debate: NSX or Vaporcar? 
02-23-2015, 02:15 PM
#442
Racer
I can't believe this thread even went beyond one page - we're beating a dead horse with another dead horse. If you can't afford the couple of extra bucks to use premium, you have bigger problems that need to be addressed.
All this "engineering" that's been going on in this thread has already been done in 2003, and probably again in 2006, by people who know a lot more about the car than any of us do.
All this "engineering" that's been going on in this thread has already been done in 2003, and probably again in 2006, by people who know a lot more about the car than any of us do.
Last edited by bla8291; 02-23-2015 at 02:17 PM.
02-26-2015, 05:21 PM
#444
Team Owner
A few things that need to be said.
Do not compare compression ratio and octane between DI and port injected cars. A direct injection car can run a much higher compression ratio and/or boost level for a given octane than a port injected engine. My BMW is somewhere around 11:1 and currently runs 22psi boost on 91. My GN (port injected) can run 17psi with an 8.5:1 comp ratio.
Keep in mind effective compression ratio is what matters, not mechanical ratio. Cam and head design have a big role. A small cammed car will have more compression while running at low engine speeds.
If the car does not detonate on 87, 91 will do nothing.
The knock sensor is reactive, not proactive. It can only react to detonation, it can't prevent it. Relying on the knock sensor as a form of tuning by either an individual or a manufacturer is wrong. The knock sensor is there to soften the blow for a short period of time, such as the owner accidentally running 87 once or twice.
Once detonation starts, much more timing has to be pulled to stop it than if it never started.
Minor detonation that's inaudible usually will not result in broken parts but it will take its toll on rings, pistons, head gaskets, and rod hearings over time.
Retarded timing significantly raises exhaust gas temperature which is harder on the exhaust valves, converters, and 02 sensors. Driving around with retarded timing all the time because you refuse to run premium is not the solution.
As hp levels go up, the inaudible detonation can result in broken parts. I can't hear mine until there's about 12 degrees of knock retard occurring. By then it's too late and I have a blown head gasket.
If a car says to run premium, this is a very wise idea. Many people do not like buying cars that require premium so the manufacturer is not going to install the premium only stickers unless it's required.
The only exception is if the car knows what octane is being used and switches to a different timing map beforehand. You will lose power and mpg but the engine will be as reliable as ever.
Be happy your car is tuned for premium. It will get better mileage and make more power than the identical car tuned for 87.
Lower octane fuel does not mean more carbon buildup nor does it mean it's faster or slower burning or has more or less energy content than higher octane fuel. The only truth to the carbon buildup is premium usually has more detergents, sometimes 2-3x more than regular. For those with DI engines you better use premium whether it requires it or not, especially Shell.
Again, do not compare DI to Port injected cars to support your argument. It's apples to oranges and its been done several times in this thread.
The TL will detonate on 87. It might not do it constantly but it will detonate, period. Your ears are not the best tool for hearing the detonation, keep that in mind.
Do not compare compression ratio and octane between DI and port injected cars. A direct injection car can run a much higher compression ratio and/or boost level for a given octane than a port injected engine. My BMW is somewhere around 11:1 and currently runs 22psi boost on 91. My GN (port injected) can run 17psi with an 8.5:1 comp ratio.
Keep in mind effective compression ratio is what matters, not mechanical ratio. Cam and head design have a big role. A small cammed car will have more compression while running at low engine speeds.
If the car does not detonate on 87, 91 will do nothing.
The knock sensor is reactive, not proactive. It can only react to detonation, it can't prevent it. Relying on the knock sensor as a form of tuning by either an individual or a manufacturer is wrong. The knock sensor is there to soften the blow for a short period of time, such as the owner accidentally running 87 once or twice.
Once detonation starts, much more timing has to be pulled to stop it than if it never started.
Minor detonation that's inaudible usually will not result in broken parts but it will take its toll on rings, pistons, head gaskets, and rod hearings over time.
Retarded timing significantly raises exhaust gas temperature which is harder on the exhaust valves, converters, and 02 sensors. Driving around with retarded timing all the time because you refuse to run premium is not the solution.
As hp levels go up, the inaudible detonation can result in broken parts. I can't hear mine until there's about 12 degrees of knock retard occurring. By then it's too late and I have a blown head gasket.
If a car says to run premium, this is a very wise idea. Many people do not like buying cars that require premium so the manufacturer is not going to install the premium only stickers unless it's required.
The only exception is if the car knows what octane is being used and switches to a different timing map beforehand. You will lose power and mpg but the engine will be as reliable as ever.
Be happy your car is tuned for premium. It will get better mileage and make more power than the identical car tuned for 87.
Lower octane fuel does not mean more carbon buildup nor does it mean it's faster or slower burning or has more or less energy content than higher octane fuel. The only truth to the carbon buildup is premium usually has more detergents, sometimes 2-3x more than regular. For those with DI engines you better use premium whether it requires it or not, especially Shell.
Again, do not compare DI to Port injected cars to support your argument. It's apples to oranges and its been done several times in this thread.
The TL will detonate on 87. It might not do it constantly but it will detonate, period. Your ears are not the best tool for hearing the detonation, keep that in mind.
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Matt
03-01-2015, 09:58 PM
#447
Instructor
Assuming the manufacturer knows nothing about the car (?) then why stop at fuel octane? Using that logic why not save a few bucks and run lower quality oil? Lower quality plugs? Etc. Personaly we bought our car to enjoy, not trash. IMHO using non-recommended fuel is a risk we won't take.
Moderator, can we please close this thread?
Moderator, can we please close this thread?
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03-02-2015, 10:55 AM
#448
I tried a couple gallons of 87 in the cool of winter in my '06 TL mt. It behaves with an easy throttle like 91. On a hill in a gear or two higher than normal, it pings until the knock sensor catches up and corrects it (mostly). I'll try 89 sometime, but I doubt there is any good choice but 91.........or even 93 if you can get it.
03-02-2015, 11:01 AM
#449
Registered Bike Offender
iTrader: (3)
Haha you guys.
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
03-02-2015, 11:08 AM
#450
Senior Moderator
iTrader: (1)
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Joe...
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ggesq (03-02-2015)
03-02-2015, 12:05 PM
#452
Race Director
Haha you guys.
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
Yes, I've run several hard pulls to just short of redline in 3rd gear and the plugin did not detect detonation. Some of the pulls were on a decent uphill stretch as well. Temp was ~40F.
03-02-2015, 06:55 PM
#453
Team Owner
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nfnsquared (03-02-2015)
03-02-2015, 07:04 PM
#454
Registered Bike Offender
iTrader: (3)
I wonder how that plugin works and if the developer would put the source code out there. Essentially he's using the same data that's already on the CAN Bus but is able to somehow meaningfully interpret it to determine if knocking is occurring. I can't access the play store at work, I'll check it out when I get home.
03-02-2015, 07:16 PM
#455
Race Director
^^^^^^^
https://acurazine.com/forums/third-g.../#post15318725
Yeah, like I said earlier, it's not clear to me how it does it. It says it uses a heuristic algorithm to find detonations based on analysis of timing advance, throttle, revs and speed. But it also says it will report ECU learned detonations. So, it's a bit confusing to me.
3rd gear, start at low speed, WOT until redline or the app completes....
3rd gear, start at low speed, WOT until redline or the app completes....
03-03-2015, 05:06 PM
#458
Knock Detector will not report minor car specific knock events so it can also miss some detonations. However it will report ECU learned detonations. Such knock events will likely disappear at some moment. Detonations can be real or fake, they can appear and disappear, so there is no reason to worry if such are reported. Detonation may be caused just by depressing the throttle at high revs. Some stock ECUs pull timing 0.5 - 1.00 even on WOT so fake knock will be detected.
Engine coolant and intake air temperaturesare also monitored as major knock factors. Avoid spirited driving or testing when both values are not green - too cold or too hot temperatures can cause detonations.
More features are coming soon. Used every day on my heavily modified Subaru STI ! Drive safe and have fun !"
https://play.google.com/store/apps/details?id=com.nosoftskills.kd
C'mon Vlad, close enough
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Vlad_Type_S (03-03-2015)
03-03-2015, 05:19 PM
#459
Registered Bike Offender
iTrader: (3)
"In order to work on all car models Knock Detector uses heuristic algorithm to find detonations. It is based on analysis of timing advance, throttle, revs and speed. On some ECUs it may report knocks but the reason could be timing retard because of specific factory tune.
Knock Detector will not report minor car specific knock events so it can also miss some detonations. However it will report ECU learned detonations. Such knock events will likely disappear at some moment. Detonations can be real or fake, they can appear and disappear, so there is no reason to worry if such are reported. Detonation may be caused just by depressing the throttle at high revs. Some stock ECUs pull timing 0.5 - 1.00 even on WOT so fake knock will be detected.
Engine coolant and intake air temperaturesare also monitored as major knock factors. Avoid spirited driving or testing when both values are not green - too cold or too hot temperatures can cause detonations.
More features are coming soon. Used every day on my heavily modified Subaru STI ! Drive safe and have fun !"
https://play.google.com/store/apps/details?id=com.nosoftskills.kd
C'mon Vlad, close enough
Knock Detector will not report minor car specific knock events so it can also miss some detonations. However it will report ECU learned detonations. Such knock events will likely disappear at some moment. Detonations can be real or fake, they can appear and disappear, so there is no reason to worry if such are reported. Detonation may be caused just by depressing the throttle at high revs. Some stock ECUs pull timing 0.5 - 1.00 even on WOT so fake knock will be detected.
Engine coolant and intake air temperaturesare also monitored as major knock factors. Avoid spirited driving or testing when both values are not green - too cold or too hot temperatures can cause detonations.
More features are coming soon. Used every day on my heavily modified Subaru STI ! Drive safe and have fun !"
https://play.google.com/store/apps/details?id=com.nosoftskills.kd
C'mon Vlad, close enough
Seems that this feature is pretty unreliable then. That's disappointing.
03-03-2015, 06:15 PM
#460
Race Director
Maybe, maybe not. Pretty sure it's measuring those parameters and like it says, uses heuristics to interpret whether a timing retard is due to engine load or due to detonation. That's the best you can ask for since there is no OBD PID for knock sensor activation (unless there's an unpublished extended PID set for Acura).
There's no way to really know for sure though. And no way to directly measuring knock/detonation via OBD either. The app is basically doing what we are trying to do manually by recording comparable engine load/rpm/timing advance between 87 and 91.
There's no way to really know for sure though. And no way to directly measuring knock/detonation via OBD either. The app is basically doing what we are trying to do manually by recording comparable engine load/rpm/timing advance between 87 and 91.
03-03-2015, 11:21 PM
#461
Haha you guys.
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
Serious question - is there a way to monitor detonation using Torque + ELM327?
I've been collecting data on timing advance, rpm, and load so I can post that, but I don't think it tells the full story anyway. I'd love to collect data on detonations.
Any of the 87 guys have that Knock Detector plugin for Torque? Have you tried using that? If so, at what RPM range did you use it?
I've floored it until 80mph and it showed Throttle position at 75%, so idk if that plugin is credible.
03-04-2015, 04:51 AM
#462
Race Director
I haven't used it for 87 octane, but I've used the Knock Detector plugin for Torque. I don't think it's an accurate plugin. I think you have to keep it in 1st gear and keep your foot to the ground and let the car bounce off the rev limiter for 2-3 seconds til the plugin even says "Throttle" 100%.
I've floored it until 80mph and it showed Throttle position at 75%, so idk if that plugin is credible.
I've floored it until 80mph and it showed Throttle position at 75%, so idk if that plugin is credible.
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Acura-OC (03-04-2015)
03-04-2015, 09:15 AM
#463
EDIT: I'll tell you this; while I was test beater cars, I used obd2 bluetooth paired with Torque, and I scanned 3 cylinders misfiring codes, this was on a 96 camry V6.
I launch the Knock Detector plugin that came with Torque, and I floored it. I started feeling the engine misfire; I can describe it as you putting your foot down, and slightly let go from WOT. It's like the RPM's would climb and then go back a little, then climb again.
The plugin? Didn't detect anything; end edit. then again, knocking and misfiring might not be related.....lolol
Last edited by OsK; 03-04-2015 at 09:25 AM. Reason: adding story
03-04-2015, 12:37 PM
#464
Burning Brakes
Sounds like people need to get Hondata FlashPro 
. I tried running 1 tank of 87 for shits and giggles since it was extremely cold in WI. The OEM knock sensor picked up 2 and 3 knocks during two 3rd gear pulls, if I had FlashPro handy I could tell you which cylinders experienced knock. I was watching this via phone app to let me know if I saw 5 to 10 knocks to abort the pull.
Just driving around normally in extremely cold ambient conditions with 87 the PCM didn't report any knock counts. If the PCM doesn't see it, it doesn't count. I am now happy to say I am back on a healthy diet 91 octane dino juice.
. I tried running 1 tank of 87 for shits and giggles since it was extremely cold in WI. The OEM knock sensor picked up 2 and 3 knocks during two 3rd gear pulls, if I had FlashPro handy I could tell you which cylinders experienced knock. I was watching this via phone app to let me know if I saw 5 to 10 knocks to abort the pull.Just driving around normally in extremely cold ambient conditions with 87 the PCM didn't report any knock counts. If the PCM doesn't see it, it doesn't count
. I am now happy to say I am back on a healthy diet 91 octane dino juice.
03-04-2015, 12:50 PM
#465
Race Director
You're right. But if it can't detect my throttle position, it just loses credibility; we can agree on that right?
EDIT: I'll tell you this; while I was test beater cars, I used obd2 bluetooth paired with Torque, and I scanned 3 cylinders misfiring codes, this was on a 96 camry V6.
I launch the Knock Detector plugin that came with Torque, and I floored it. I started feeling the engine misfire; I can describe it as you putting your foot down, and slightly let go from WOT. It's like the RPM's would climb and then go back a little, then climb again.
The plugin? Didn't detect anything; end edit. then again, knocking and misfiring might not be related.....lolol
EDIT: I'll tell you this; while I was test beater cars, I used obd2 bluetooth paired with Torque, and I scanned 3 cylinders misfiring codes, this was on a 96 camry V6.
I launch the Knock Detector plugin that came with Torque, and I floored it. I started feeling the engine misfire; I can describe it as you putting your foot down, and slightly let go from WOT. It's like the RPM's would climb and then go back a little, then climb again.
The plugin? Didn't detect anything; end edit. then again, knocking and misfiring might not be related.....lolol
Absolute throttle position (not “relative” or “learned” throttle position) shall be displayed as a normalised value, scaled from 0 to 100%. For example, if a 0 to 5.0 volt sensor is used (uses a 5.0 volt reference voltage), and the closed throttle position is a 1.0 volts, TP shall display (1.0 / 5.0) = 20% at closed throttle and 50% at 2.5 volts. Throttle position at idle will usually indicate greater than 0%, and throttle position at wide open throttle will usually indicate less than 100%.
For systems where the output is proportional to the input voltage, this value is the percent of maximum input reference voltage. For systems where the output is inversely proportional to the input voltage, this value is 100% minus the percent of maximum input reference voltage.
How can it do this?
03-04-2015, 01:45 PM
#466
Burning Brakes
The same way it knows when to inject fuel and ignite the mixture, crank position sensor.
03-04-2015, 01:56 PM
#467
Race Director
Huh? Again, tell me how the flashpro can tell which individual cylinder/s was/were knocking? Show me where in the manual it says it can do this.
03-04-2015, 02:26 PM
#468
But again, there is no direct input from the knock sensor to the flashpro or OBD, so you can never be certain that the knock sensor was activated based upon flashpro readings.
Huh? Again, tell me how the flashpro can tell which individual cylinder/s was/were knocking? Show me where in the manual it says it can do this.
Huh? Again, tell me how the flashpro can tell which individual cylinder/s was/were knocking? Show me where in the manual it says it can do this.
03-04-2015, 02:43 PM
#469
Race Director
No!! There is only one knock sensor. It doesn't know which cylinder/s is/are knocking..
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Vlad_Type_S (03-05-2015)
03-04-2015, 05:41 PM
#471
Race Director
Although I don't know for sure, I highly doubt that. I've never seen any indication that the stock ECU controls individual cylinder timing. I'm 99.9% sure it just pulls timing across the board.
03-04-2015, 06:13 PM
#473
Race Director
Again:
With the flashpro, it appears you can alter the tables by cylinder, but even then, it's not "reactive". The tables are/can be adjusted according to a specific tune, but I don't see anything about the ECU reacting "on the fly"/real time to individual cylinder knock.
With the flashpro, it appears you can alter the tables by cylinder, but even then, it's not "reactive". The tables are/can be adjusted according to a specific tune, but I don't see anything about the ECU reacting "on the fly"/real time to individual cylinder knock.
03-04-2015, 08:15 PM
#474
Burning Brakes
Again:
With the flashpro, it appears you can alter the tables by cylinder, but even then, it's not "reactive". The tables are/can be adjusted according to a specific tune, but I don't see anything about the ECU reacting "on the fly"/real time to individual cylinder knock.
With the flashpro, it appears you can alter the tables by cylinder, but even then, it's not "reactive". The tables are/can be adjusted according to a specific tune, but I don't see anything about the ECU reacting "on the fly"/real time to individual cylinder knock.
Here's my 3rd Gear Pull on 87.
The PCM can record knock and provide the knock location based off the cylinder that is currently in the combustion cycle. I didn't say the PCM will reduce ignition timing for that cylinder, but rather global timing. You wouldn't want to alter timing very much on an individual cylinder basis since it would cause a power imbalance relative to the other cylinders.
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CrazyEights (03-04-2015)
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03-04-2015, 09:41 PM
#476
Race Director
Here's my 3rd Gear Pull on 87.
The PCM can record knock and provide the knock location based off the cylinder that is currently in the combustion cycle. I didn't say the PCM will reduce ignition timing for that cylinder, but rather global timing. You wouldn't want to alter timing very much on an individual cylinder basis since it would cause a power imbalance relative to the other cylinders.
A knock retard of only 3 degrees? That doesn't sound right to me. I'd think knock retard would be a lot more than that... Just saying....
03-05-2015, 12:17 AM
#478
Chapter Leader (Southern Region)
03-05-2015, 07:25 AM
#479
This is exactly why this thread is the way it is. I wonder if he also pm a moderator over onepumpchump post, but I guess not because it works in his favor. Again, you post something J and NFN runs to a moderator to cry about your post. funny how he posts crap about me and you didn't see me run to a moderator to about it, nor did it when that other special individual onepumpchump did. It's amazing NFN and Rustylogic set all these pathetic rules in here like they are somebody special and clearly break their own rules. It is time to close this thread.
03-05-2015, 07:34 AM
#480
iWhine S/C 6MT TL
iTrader: (1)
It's exhausting already with him. It's all irrelevant. No idea why you guys bother being constructive and posting information pertaining to this god forsaken thread, just to be told NO, wrong, no no no no no, wrong wrong wrong. Just agree with them about what they want to hear and call it a day.