AccessTUNER Race for RX8 Released!!!
04-22-2012, 03:01 PM
#202
OK, let’s try this again. I recorded a 2nd gear pull on a warm afternoon when IATs were approaching 100F. A couple days later I made the same run early in the morning with IAT~60F. At 6000 RPM on the warm day, the data logged “calculated load” was 94. On the cool run it was 100 at the same RPM. Indicated AFR was approximately the same for both runs.
So the question is, to adjust AFR at this point, do I target the cell at .94, at 1.00, or (correcting both to 77F) at .97? Obviously I can just adjust all of the cells in the column an equal percentage, but this seems like a pretty crude way to tune a system that Mazda has obviously invested a lot of time in to make indecipherable.
So the question is, to adjust AFR at this point, do I target the cell at .94, at 1.00, or (correcting both to 77F) at .97? Obviously I can just adjust all of the cells in the column an equal percentage, but this seems like a pretty crude way to tune a system that Mazda has obviously invested a lot of time in to make indecipherable.
I have found it useful to estimate this using a WOT log data of MAF g/s and this formula:
Code:
MAF/(BARO kPa/(287.058*(IAT C+273.15))*(1308*RPM/60))
If you can manage to get this dead on, it does a good job of compensating for errors that the MAF, even when perfectly calibrated, cannot, due to weird things that happen with a variable intake (backflow, resonance, etc.)
Quoting myself from this thread.
So the ECU is simply calculating the mass of air needing fuel, and then the mass of fuel required.
The fuel tables then really should correspond to the resultant mixture. To get the desired lambda, the basic calculation is just:
closed loop table A or B* + either closed loop throttle enrichment table OR current open loop enrichment value
Right now, I have all my open loop enrichment tables zeroed, stock MAF scale, stock fuel injector flow rates, stock VE table, and the air fuel ratio is set by the closed loop A table only. Oh, and the measured AFR corresponds well, and is robust when weather changes.
*closed loop table B is only used to set a correction to the front O2 sensor based on the rear O2 sensor, ie very rarely and only at cruise loads/rpms, and it should not be changed.
Last edited by oltmann; 04-22-2012 at 03:04 PM.
04-22-2012, 08:36 PM
#203
OK, let’s try this again. I recorded a 2nd gear pull on a warm afternoon when IATs were approaching 100F. A couple days later I made the same run early in the morning with IAT~60F. At 6000 RPM on the warm day, the data logged “calculated load” was 94. On the cool run it was 100 at the same RPM. Indicated AFR was approximately the same for both runs.
So the question is, to adjust AFR at this point, do I target the cell at .94, at 1.00, or (correcting both to 77F) at .97? Obviously I can just adjust all of the cells in the column an equal percentage, but this seems like a pretty crude way to tune a system that Mazda has obviously invested a lot of time in to make indecipherable.
So the question is, to adjust AFR at this point, do I target the cell at .94, at 1.00, or (correcting both to 77F) at .97? Obviously I can just adjust all of the cells in the column an equal percentage, but this seems like a pretty crude way to tune a system that Mazda has obviously invested a lot of time in to make indecipherable.
will lead you to believe. I'm not saying he is incorrect, only that he can't relate simple layman terms and all around simplicity by eliminating theory that is basically correct, but amounts to minutia in the real world results.
04-24-2012, 03:22 AM
#204
Fair critique, but all the jargon isn't there to make me feel smart. Well, not exclusively. 
If you want to understand how the ecu works, I think you'll also need to learn some substantial portion of what the calibration engineers at Mazda/Denso knew. I've spent a rather shameful amount of time trying to learn this, and I still feel like I'm missing big chunks. However, if someone does want to learn, perhaps the jargon will serve as a guide as they pour through textbooks and research papers.
If you just want a decent tune, this isn't really required. But I do think that the formula I posted may be helpful to set up the max load table, just open a WOT run in Excel and add it to a new column.
If you want to understand how the ecu works, I think you'll also need to learn some substantial portion of what the calibration engineers at Mazda/Denso knew. I've spent a rather shameful amount of time trying to learn this, and I still feel like I'm missing big chunks. However, if someone does want to learn, perhaps the jargon will serve as a guide as they pour through textbooks and research papers.
If you just want a decent tune, this isn't really required. But I do think that the formula I posted may be helpful to set up the max load table, just open a WOT run in Excel and add it to a new column.
04-24-2012, 09:09 AM
#206
and if the air is cold (dense) or the baro high (dense) the maps coordinate to bump up the calc load which in turn the fuel map is structured to compensate for the increased oxygen mass with more fuel
I would recommend going easy on the map blending, at least in the high load areas. If you determine target settings at specific load points, but then turn around and blend them following later changes you make somewhere else in the map you have in fact altered those map points from what the data has already shown you to be ideal. Unless you prefer to chase your own tail in circles.
The idea that everything has to proceed on some smooth, linear curve is a fallacy. The engine needs what it needs when it needs it based on the specific dynamics that occur under those specific conditions (like an intake valve suddenly opening), which may vary quite a bit due to the intake harmonics and effect that density and other variables can have. Things are also a bit different between NA and FI, so also be careful not to read something associated with one and erroneously apply it to the other.
.
I would recommend going easy on the map blending, at least in the high load areas. If you determine target settings at specific load points, but then turn around and blend them following later changes you make somewhere else in the map you have in fact altered those map points from what the data has already shown you to be ideal. Unless you prefer to chase your own tail in circles.
The idea that everything has to proceed on some smooth, linear curve is a fallacy. The engine needs what it needs when it needs it based on the specific dynamics that occur under those specific conditions (like an intake valve suddenly opening), which may vary quite a bit due to the intake harmonics and effect that density and other variables can have. Things are also a bit different between NA and FI, so also be careful not to read something associated with one and erroneously apply it to the other.
.
Last edited by TeamRX8; 04-24-2012 at 09:34 AM.
04-24-2012, 10:09 PM
#207
I appreciate the various comments and recommendations, but I haven't really got an answer to my original question (or at least have gotten inconsistent answers). Maybe nobody really knows.
Anyway, I’ve roughed the AFRs in pretty well by trial and error, but I still can’t make any sense of the logic behind the different tables, and my experience doesn’t seem consistent with the documentation in ATR
BTW: I understand the physics behind this thoroughly (I do this for a living on gas turbines). I’m just perplexed by Mazda’s Rube-Goldberg control scheme.
Thanks,
Jim
Anyway, I’ve roughed the AFRs in pretty well by trial and error, but I still can’t make any sense of the logic behind the different tables, and my experience doesn’t seem consistent with the documentation in ATR
BTW: I understand the physics behind this thoroughly (I do this for a living on gas turbines). I’m just perplexed by Mazda’s Rube-Goldberg control scheme.
Thanks,
Jim
04-25-2012, 12:45 AM
#208
The documentation in ATR isn't great...so using it as the basis of your confusion is likely causing the confusion 
We are unable to directly control a lot of the variables the ECU uses to control the calc load and therefore the fueling.
Basically we use the fueling tables and the Ve table to alter the outputs until we get the AFR we want at the sensor ( and hopefully the engine )
We are unable to directly control a lot of the variables the ECU uses to control the calc load and therefore the fueling.
Basically we use the fueling tables and the Ve table to alter the outputs until we get the AFR we want at the sensor ( and hopefully the engine
)
04-25-2012, 12:51 PM
#209
The ATR manual is a blend of things either wrong or incomplete.
The HTML version of the workshop manuals has better information, can't find the link, but I'll export the page on fuel injection control as a pdf.
The HTML version of the workshop manuals has better information, can't find the link, but I'll export the page on fuel injection control as a pdf.
04-28-2012, 08:52 AM
#212
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Ok so I have an AP, running the stage1 cobb tune, but I want to clear my cel to get an inspection today.
To request accesstuner will take a day so I've read, but does anyone know if mazdamaniacs base tune clear the o2 heater monitor.
My code is for the rear o2 heater btw.
To request accesstuner will take a day so I've read, but does anyone know if mazdamaniacs base tune clear the o2 heater monitor.
My code is for the rear o2 heater btw.
05-17-2012, 10:41 PM
#213
This is the newest ATR download request page
http://www.cobbtuning.com/accesstune...st-s/70716.htm
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http://www.cobbtuning.com/accesstune...st-s/70716.htm
.
Last edited by TeamRX8; 07-01-2013 at 04:26 PM.
05-18-2012, 05:19 PM
#214
Is this 4 port an automatic? What year? What mods?
I'm really curious on how "getting it tuned" keeps your warranty?
Unless you're FI I wouldn't expect much in the way of HP gains when you hit the dyno.
Maybe 150~160 hp at the wheels if it's an Auto and 190-205 if it's a manual
I'm really curious on how "getting it tuned" keeps your warranty?
Unless you're FI I wouldn't expect much in the way of HP gains when you hit the dyno.
Maybe 150~160 hp at the wheels if it's an Auto and 190-205 if it's a manual
we didnt get the auto in the UK buddy, rx8 models came in low power 192 ps (4 port) with a 5 speed box and high power 231 ps with the 6 speed box
the 4 port cars run slightly more torque than the 6 port motors but only rev to about 8350 rpm :-(
Arnies car's had a lot of time and money spent on it ... its about as quik as a standard 6 port now - doesnt really matter over here tho we dont have any straight roads to test it on so its all in the cornering
oh and its not mazdas warrenty he's keeping, its haywards warrenty on the engine :-)
05-22-2012, 06:13 AM
#216
we didnt get the auto in the UK buddy, rx8 models came in low power 192 ps (4 port) with a 5 speed box and high power 231 ps with the 6 speed box
the 4 port cars run slightly more torque than the 6 port motors but only rev to about 8350 rpm :-(
Arnies car's had a lot of time and money spent on it ... its about as quik as a standard 6 port now - doesnt really matter over here tho we dont have any straight roads to test it on so its all in the cornering
oh and its not mazdas warrenty he's keeping, its haywards warrenty on the engine :-)
the 4 port cars run slightly more torque than the 6 port motors but only rev to about 8350 rpm :-(
Arnies car's had a lot of time and money spent on it ... its about as quik as a standard 6 port now - doesnt really matter over here tho we dont have any straight roads to test it on so its all in the cornering
oh and its not mazdas warrenty he's keeping, its haywards warrenty on the engine :-)
I've been there for 9 weeks, got to see some really beautiful cars.
(business trip, I'm not Welsh)
You don't get to see as large of a variety of vehicles in North America as you can in the UK. To bad it rains so much there.
I would love to see the dyno on an Automatic that is NA and producing near as much horsepower as a MT (well as quick).
What are the mods and how the hell is he insuring it? I know your insurance companies are crazy weird with rules and extra costs for modifying your vehicles.
05-23-2012, 03:17 PM
#217
mate you have no idea! and prices are stupendous too!! a 17 year old (youngest possible) can expect to pay £5000 a year to insure a £500 1.2 vauxal corsa in some cases
also we insure the car, not ourselves - so you carnt just jump in your parents car and drive about inusred
anyway - arnies cars not an auto its a 5 speed manual 4 port, we didnt get the auto over here - the '192 ps' is what we got instead
arnie's mod list is huge!! tho nothing loke some of the your lots! ill point him in this direction he can explain haha
Yes it always rains in wales ... strange place with gobblins and trolls roming about n stuff but there are some amazing roads there!!!!
also we insure the car, not ourselves - so you carnt just jump in your parents car and drive about inusred
anyway - arnies cars not an auto its a 5 speed manual 4 port, we didnt get the auto over here - the '192 ps' is what we got instead
arnie's mod list is huge!! tho nothing loke some of the your lots! ill point him in this direction he can explain haha
Yes it always rains in wales ... strange place with gobblins and trolls roming about n stuff but there are some amazing roads there!!!!
06-15-2012, 03:20 PM
#218
07-22-2012, 04:58 AM
#219
Ok so im sorry for my ignorance on this. But, i havent a clue whats going on here. We can actually download a program that will let us custom tune our cars for free? Where do i get the cord and how much is it? What exactly can i chamge with this? Can someone please pm me on this and give me an understanding. Im very very interested. Thank you much for your time and hapoy driving all
07-22-2012, 09:07 AM
#220
Ok so im sorry for my ignorance on this. But, i havent a clue whats going on here. We can actually download a program that will let us custom tune our cars for free? Where do i get the cord and how much is it? What exactly can i chamge with this? Can someone please pm me on this and give me an understanding. Im very very interested. Thank you much for your time and hapoy driving all
If you need to ask these questions you're clearly not an individual that should be using this tool.
However I like to see someone **** up their car as much as the next guy.
Buy the Cobb AP from www.mazdamaniac.com or from someone selling a used one on the forum.
Download ATR from here
https://www.rx8club.com/engine-tunin...ftware-235322/
Have fun
Last edited by wcs; 07-22-2012 at 12:01 PM.
07-22-2012, 09:33 AM
#221
Ok so I have an AP, running the stage1 cobb tune, but I want to clear my cel to get an inspection today.
To request accesstuner will take a day so I've read, but does anyone know if mazdamaniacs base tune clear the o2 heater monitor.
My code is for the rear o2 heater btw.
To request accesstuner will take a day so I've read, but does anyone know if mazdamaniacs base tune clear the o2 heater monitor.
My code is for the rear o2 heater btw.
07-23-2012, 06:44 AM
#222
I dont want to **** my car up and i understand exactly what this is , i just got confused and thought you could do all this for free as long as you had the $20 bluetooth obd2 plug from my labtop.
Why would you want to see someone mess there car up? You a little bitter from having an experience like such? Not cool bro. But thanks for the link.
I dont know what next guy your talking about but he sounds like a dick. I know none of my friends nor myself would ever like to see someone **** there car up but would much rather give them a hand in not doing so.
However if you were just messin around not tryin to he rude and sarcastically givin me a heads up that its dangerous then thanks for the heads, if not then no thanks at all bro.
Why would you want to see someone mess there car up? You a little bitter from having an experience like such? Not cool bro. But thanks for the link.
I dont know what next guy your talking about but he sounds like a dick. I know none of my friends nor myself would ever like to see someone **** there car up but would much rather give them a hand in not doing so.
However if you were just messin around not tryin to he rude and sarcastically givin me a heads up that its dangerous then thanks for the heads, if not then no thanks at all bro.
