Official SHARKTUNER thread
03-12-2008, 06:14 PM
#226
Three Wheelin'
John,
What I was wondering about, and didn't explain sufficiently, is that the ST gets the WB output and presumably that will give the correct AFR. That is what is used to generate the map in "Autotune" since the LH is put into open loop during that time. When autotune is turned off, the ST still reads the mixture from the WB, but now the LH is using the NB input to keep the mixture correct in closed loop.
You have two different sensor inputs. The NB is doing the mixture controlling through the LH. If you're using a simulated NB from the WB, and it isn't at 0.45 volts when the mixture is actually at 14.7 AFR (as read on the WB driven ST), you'll get the situation Tony describes. The LH will drive the closed loop mixture to achieve an average of 0.45 volts at the LH O2 sensor input. That's all it knows to do. If the 0.45 volts NB input isn't really 14.7 AFR, then it'll show up on the ST as something different.
If you are using the regular NB sensor feeding the LH when the LH is in closed loop, and the ST (WB) mixture is not around 14.7, then the calibration of the WB sensor is in question, or the NB sensor is no good.
The WB and NB inputs offer a good opportunity to cross check the NB and WB correlation. They should match within a few tenths of an AFR.
What I was wondering about, and didn't explain sufficiently, is that the ST gets the WB output and presumably that will give the correct AFR. That is what is used to generate the map in "Autotune" since the LH is put into open loop during that time. When autotune is turned off, the ST still reads the mixture from the WB, but now the LH is using the NB input to keep the mixture correct in closed loop.
You have two different sensor inputs. The NB is doing the mixture controlling through the LH. If you're using a simulated NB from the WB, and it isn't at 0.45 volts when the mixture is actually at 14.7 AFR (as read on the WB driven ST), you'll get the situation Tony describes. The LH will drive the closed loop mixture to achieve an average of 0.45 volts at the LH O2 sensor input. That's all it knows to do. If the 0.45 volts NB input isn't really 14.7 AFR, then it'll show up on the ST as something different.
If you are using the regular NB sensor feeding the LH when the LH is in closed loop, and the ST (WB) mixture is not around 14.7, then the calibration of the WB sensor is in question, or the NB sensor is no good.
The WB and NB inputs offer a good opportunity to cross check the NB and WB correlation. They should match within a few tenths of an AFR.
03-13-2008, 02:54 AM
#227
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John,
What I was wondering about, and didn't explain sufficiently, is that the ST gets the WB output and presumably that will give the correct AFR. That is what is used to generate the map in "Autotune" since the LH is put into open loop during that time. When autotune is turned off, the ST still reads the mixture from the WB, but now the LH is using the NB input to keep the mixture correct in closed loop.
You have two different sensor inputs. The NB is doing the mixture controlling through the LH. If you're using a simulated NB from the WB, and it isn't at 0.45 volts when the mixture is actually at 14.7 AFR (as read on the WB driven ST), you'll get the situation Tony describes. The LH will drive the closed loop mixture to achieve an average of 0.45 volts at the LH O2 sensor input. That's all it knows to do. If the 0.45 volts NB input isn't really 14.7 AFR, then it'll show up on the ST as something different.
If you are using the regular NB sensor feeding the LH when the LH is in closed loop, and the ST (WB) mixture is not around 14.7, then the calibration of the WB sensor is in question, or the NB sensor is no good.
The WB and NB inputs offer a good opportunity to cross check the NB and WB correlation. They should match within a few tenths of an AFR.
What I was wondering about, and didn't explain sufficiently, is that the ST gets the WB output and presumably that will give the correct AFR. That is what is used to generate the map in "Autotune" since the LH is put into open loop during that time. When autotune is turned off, the ST still reads the mixture from the WB, but now the LH is using the NB input to keep the mixture correct in closed loop.
You have two different sensor inputs. The NB is doing the mixture controlling through the LH. If you're using a simulated NB from the WB, and it isn't at 0.45 volts when the mixture is actually at 14.7 AFR (as read on the WB driven ST), you'll get the situation Tony describes. The LH will drive the closed loop mixture to achieve an average of 0.45 volts at the LH O2 sensor input. That's all it knows to do. If the 0.45 volts NB input isn't really 14.7 AFR, then it'll show up on the ST as something different.
If you are using the regular NB sensor feeding the LH when the LH is in closed loop, and the ST (WB) mixture is not around 14.7, then the calibration of the WB sensor is in question, or the NB sensor is no good.
The WB and NB inputs offer a good opportunity to cross check the NB and WB correlation. They should match within a few tenths of an AFR.
So in a perfect world it wouldnt be a bad idea to go out and get a new bosch O2 sensor and a new wide band 02 for my LM-1 and install them at the same time. Thus in theory they should be pretty damn close to each other in calibration. Im not using the simulated out put signal from the LM-1. The stock sesnor goes into the LH...the cord from the ST goes into the LM-1.
We did have to unplug the stock 02 sensor for the intial startup using the 42lbs injectors though.
Runs great really. just a minor thing at this point that we were both curious about.
thanks for the answers.
03-13-2008, 05:11 AM
#230
Three Wheelin'
So in a perfect world it wouldnt be a bad idea to go out and get a new bosch O2 sensor and a new wide band 02 for my LM-1 and install them at the same time. Thus in theory they should be pretty damn close to each other in calibration. Im not using the simulated out put signal from the LM-1. The stock sesnor goes into the LH...the cord from the ST goes into the LM-1.
We did have to unplug the stock 02 sensor for the intial startup using the 42lbs injectors though.
Runs great really. just a minor thing at this point that we were both curious about.
thanks for the answers.
We did have to unplug the stock 02 sensor for the intial startup using the 42lbs injectors though.
Runs great really. just a minor thing at this point that we were both curious about.
thanks for the answers.
What does the WB read on the ST after the engine is running at idle and part throttle in closed loop for a while? If the closed loop mixture is hunting fairly rapidly like every second or so, the NB sensor is probably ok. They get lazy when they are old. Closed loop reading average of 15 or leaner on the ST I think shows that your WB LM-1 is out of calibration, or possibly a ground problem in the way it is connected. Does the LM-1 reading correlate with the ST reading? A difference there would indicate a ground problem in the connection to the ST.
03-13-2008, 06:18 AM
#231
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Thanks Louie for explaining your thoughts. I knew I must have misunderstood you....
Tony - I usually adjust idle mapping manually by watching the CO loop on the system monitor and then adjust the idle cells to get the O2 loop showing around mid range.
Has the idle A/F at idle now settled down, as Louie asked ?
Tony - I usually adjust idle mapping manually by watching the CO loop on the system monitor and then adjust the idle cells to get the O2 loop showing around mid range.
Has the idle A/F at idle now settled down, as Louie asked ?
03-13-2008, 06:43 PM
#232
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Im in NYC at the moment and Ive hidden the keys from Darien
Ill play with it more when i get back Monday. Like i said its a minor detail, its just that it REALLY idles nice when its autotuning. Ive only had the ST on the car with the 42lb injectors for 1 day really...so more to come i guess.
The appearance of the Sharktuner has made many things possible, but one of them is the ability to run 42lb injectors in the 928. I will no longer have to bump up my fuel pressures to crazy levels under boost...or drop them drastically to get the car not to run rich at idle...or just start. My fuel under some boost now is appx 60 psi and according to the initial AFR, im on the rich side!! Ill know more next week when i start doing WOT tuning. I now have the idle fuel pressure set at 50psi, pretty much the rated setting for the fuel injector. The idle and "pick up" response is noticabley better.
of course the real reason i put 42lb injectors in is...
Now that Darien went and burst my bubble, i thought, OK, time to play ball.
The young Padawen shall not out gun the Jedi!
Bottom line is, you follow in the success of others. With the 42lb'ers, Super Maf, 044 fuel pump and Sharktuning my only limitiation is going to be pulley size and the associated belt slip with it. The tensioner setup on this "original" TwinScrew is about at its limit now. I drove the car for about 2 days last year with that very small pulley shown in the random pic thread...it was insanely, quick, powerfull, and boost was well north of 12-13 when i had a chance to glance at it. The belt was slipping badly so it took it off.
My goal has always been 500RWHP. Its taking me longer than others thats for sure, but ill get there. Im hoping i can "nurse the remaining 50hp out of it with good tuning, but i think i will need a smaller pulley for that last step. To do that i will most likely have to redesign/tweek the old pulley system i have. Tuning will take me only so far ya know. Gotta have the boost in the final analysis of it all.
Ill play with it more when i get back Monday. Like i said its a minor detail, its just that it REALLY idles nice when its autotuning. Ive only had the ST on the car with the 42lb injectors for 1 day really...so more to come i guess.
Tony, why did you switch to 45's?
Were you running 30's before?
Were you running 30's before?
The appearance of the Sharktuner has made many things possible, but one of them is the ability to run 42lb injectors in the 928. I will no longer have to bump up my fuel pressures to crazy levels under boost...or drop them drastically to get the car not to run rich at idle...or just start. My fuel under some boost now is appx 60 psi and according to the initial AFR, im on the rich side!! Ill know more next week when i start doing WOT tuning. I now have the idle fuel pressure set at 50psi, pretty much the rated setting for the fuel injector. The idle and "pick up" response is noticabley better.
of course the real reason i put 42lb injectors in is...
Now that Darien went and burst my bubble, i thought, OK, time to play ball.
The young Padawen shall not out gun the Jedi!
Bottom line is, you follow in the success of others. With the 42lb'ers, Super Maf, 044 fuel pump and Sharktuning my only limitiation is going to be pulley size and the associated belt slip with it. The tensioner setup on this "original" TwinScrew is about at its limit now. I drove the car for about 2 days last year with that very small pulley shown in the random pic thread...it was insanely, quick, powerfull, and boost was well north of 12-13 when i had a chance to glance at it. The belt was slipping badly so it took it off.
My goal has always been 500RWHP. Its taking me longer than others thats for sure, but ill get there. Im hoping i can "nurse the remaining 50hp out of it with good tuning, but i think i will need a smaller pulley for that last step. To do that i will most likely have to redesign/tweek the old pulley system i have. Tuning will take me only so far ya know. Gotta have the boost in the final analysis of it all.
Last edited by Tony; 03-13-2008 at 11:04 PM.
03-19-2008, 12:46 PM
#234
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These are screen shots of the data logs from the ST. Only one parameter is shown in each image as Im not sure if i can overlay one parameter over another...the scale seems to get messed up if i do. If some of you are good at photo shop you shoul be able to do a paste overlay and overlay RPM over MAF V...or AFR etc etc. Im trying to figure that out now.
Anyway, these are the logs from the last run i did. 1..2..3...and into 4th gear and to over 150ish mph if my quick glance at the speedo was correct.. The meat and potatoes of the 4th gear run starts at about the 25sec mark. I also added a pic of the fuel map, you can see the area that was tuned(green). Not an easy spot to get to on many roads
This is the map that is currently loaded in my car now for everyday driving. 42lb injectors, Super MAF, 50psi fuel pressure at idle, 63psi under boost, 10-11psi boost. Im burning a chip today, then im going to look at the Igniton side of things.
Im sure there are things that may jump out on the charts to some, but the car really runs great. Ihave no complaints. Idles wonderfully now and is overall much smoother....under boost it flys. Bill, George and other ORR, to sit with your foot to the floor in 4th at over 155mph for more than 17secs takes some serious nads!
Thats all i gotta say about that!
Digest it, study it..do what ever with the info..but i will say this Sharktuner is amazing!
Any observations are appreciated!
Anyway, these are the logs from the last run i did. 1..2..3...and into 4th gear and to over 150ish mph if my quick glance at the speedo was correct.. The meat and potatoes of the 4th gear run starts at about the 25sec mark. I also added a pic of the fuel map, you can see the area that was tuned(green). Not an easy spot to get to on many roads
This is the map that is currently loaded in my car now for everyday driving. 42lb injectors, Super MAF, 50psi fuel pressure at idle, 63psi under boost, 10-11psi boost. Im burning a chip today, then im going to look at the Igniton side of things.
Im sure there are things that may jump out on the charts to some, but the car really runs great. Ihave no complaints. Idles wonderfully now and is overall much smoother....under boost it flys. Bill, George and other ORR, to sit with your foot to the floor in 4th at over 155mph for more than 17secs takes some serious nads!
Thats all i gotta say about that!
Digest it, study it..do what ever with the info..but i will say this Sharktuner is amazing!
Any observations are appreciated!
03-19-2008, 01:21 PM
#235
Rennlist Member
Hello Tony,
You've done a great job. There's nothing on your graphs that are of any concern....... so 4600rpm in auto 4th gear = xxx mph ........ :-)
You can paste ST datalogs files into an excel spreadsheet and then manipulate in there. As you say, showing multiple plots on the ST graphing can result in some not too useful scales.
It will be interesting to hear what you find when you ST the EZK. Usually 1 or 2 cylinders are always well ahead of the rest for detonation.
Keep out of knocks, because once the system responds (quickly) to a detected knock, the ignition on that cylinder is only gradually restored to stock mapping in very small steps once knock ceases. So it can take 10-20 secs for this recovery to complete.
You've done a great job. There's nothing on your graphs that are of any concern....... so 4600rpm in auto 4th gear = xxx mph ........ :-)
You can paste ST datalogs files into an excel spreadsheet and then manipulate in there. As you say, showing multiple plots on the ST graphing can result in some not too useful scales.
It will be interesting to hear what you find when you ST the EZK. Usually 1 or 2 cylinders are always well ahead of the rest for detonation.
Keep out of knocks, because once the system responds (quickly) to a detected knock, the ignition on that cylinder is only gradually restored to stock mapping in very small steps once knock ceases. So it can take 10-20 secs for this recovery to complete.
03-19-2008, 02:14 PM
#237
Rennlist Member
Part one of this new generation we hope to release in the next few months.
03-19-2008, 02:33 PM
#238
Nordschleife Master
GOOD NEWS! I just PM'ed you asking about this very thing. Glad to see your making progress!
03-19-2008, 02:49 PM
#239
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Great work, John.
03-19-2008, 04:03 PM
#240
Three Wheelin'
