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Chassis CAN Logging To ASCII Text Plus Graphing

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#505
So we have seen under 450 ft-lbs of rear motor torque for P and PDs. Does anyone remember what the motors were spec'd to produce and if that was at the shaft or after hearing?

Answered my own question-
The spec says 718 and the PDs are putting out a combined 440 + 240 or 680. These maximums appear to be programmatically limited (i.e. not limited by the battery). 680 measured is reasonably close to 718.

I was hoping there was more potential available from the rear motor as allowing more torque from the motors when the battery was not the limiting factor would explain a 10 second run. It would appear as though Tesla is motor limited in the first second then transitions to battery limited. Given that both segments are limited, it is highly unlikely that MS can run a ten second quarter mile on flat ground.
 
Last edited:
#507
lolachampcar said:
I was hoping there was more potential available from the rear motor as allowing more torque from the motors when the battery was not the limiting factor would explain a 10 second run. It would appear as though Tesla is motor limited in the first second then transitions to battery limited. Given that both segments are limited, it is highly unlikely that MS can run a ten second quarter mile on flat ground.
Click to expand...
Keep in mind both the limits are probably mainly software. The motor limits are decided by the drive inverter software presumably to ensure the long-term reliability of itself along with the rest of the powertrain. The battery limits are being decided by the BMS, of course not the voltage sagging, that's an artifact of the cell construction and possibly somewhat affected by the physical construction of the pack.
 
#508
lolachampcar said:
So we have seen under 450 ft-lbs of rear motor torque for P and PDs. Does anyone remember what the motors were spec'd to produce and if that was at the shaft or after hearing?

Answered my own question-
The spec says 718 and the PDs are putting out a combined 440 + 240 or 680. These maximums appear to be programmatically limited (i.e. not limited by the battery). 680 measured is reasonably close to 718.

I was hoping there was more potential available from the rear motor as allowing more torque from the motors when the battery was not the limiting factor would explain a 10 second run. It would appear as though Tesla is motor limited in the first second then transitions to battery limited. Given that both segments are limited, it is highly unlikely that MS can run a ten second quarter mile on flat ground.
Click to expand...
As you say, being "motor limited" in the first second is likely a programmatic limit, so I could envision the possibility of a special (MT) version of the SW, on the "melting-edge", that increases the programmatic torque limits on both motors in the first couple of seconds. Combined with 4 tires having enough traction to handle the increased torque, this might improve the 60 ft times to 1.3 seconds. All else being equal, it might reach a 10.9XX.

That, of course, doesn't answer the question of why the production P90DL is unambiguously promoted as having a 10.9 sec ET.
 
#509
Bill,
I agree but doing so would basically be generating a car that exceeds the published torque specifications to meet a published 1/4 mile time (which indicates intent).

I guess the real conclusion for me is that I have run out of ways that Tesla might make that 1/4 which is making it look a lot like marketing BS.
 
#510
First pass at RingBuf Logger.
One second pre-trigger.
One second post trigger.
Both can be adjusted.

There is a 7/100ths loss of data (seven samples) when transitioning from pre to post trigger data.
Here is an example with a 25% TPS trigger.
Time TPS Speed R_Tq F_Tq BatV BatI R_RPM AWD
0093.52 024.8 +011.70 +094.9 +019.7 360.78 -0083.7 +01415
0093.53 024.8 +011.75 +096.2 +010.8 360.65 -0083.5 +01409
0093.61 025.6 +012.10 +105.2 +002.0 360.28 -0093.0 +01455
0093.62 025.6 +012.10 +105.8 +002.2 360.02 -0098.1 +01471

I moved the trigger field to the left one spot to make it easier to spot. The revisions are now 00x00y where
x is trigger (same as before A,B,C are TPS and D is switch) Switch code is unchanged but untested.
y is the release version

Dropbox - UPDATE_C00A00B.EBL
Dropbox - UPDATE_C00B00B.EBL
Dropbox - UPDATE_C00C00B.EBL
Dropbox - UPDATE_C00D00B.EBL
 
#511
Great stuff, thanks.

Kinda bummed I won't be near my car until Wed night, so assuming Brianman can test this out before then? :)

lolachampcar said:
First pass at RingBuf Logger.
One second pre-trigger.
One second post trigger.
Both can be adjusted.

There is a 7/100ths loss of data (seven samples) when transitioning from pre to post trigger data.
Here is an example with a 25% TPS trigger.
Time TPS Speed R_Tq F_Tq BatV BatI R_RPM AWD
0093.52 024.8 +011.70 +094.9 +019.7 360.78 -0083.7 +01415
0093.53 024.8 +011.75 +096.2 +010.8 360.65 -0083.5 +01409
0093.61 025.6 +012.10 +105.2 +002.0 360.28 -0093.0 +01455
0093.62 025.6 +012.10 +105.8 +002.2 360.02 -0098.1 +01471

I moved the trigger field to the left one spot to make it easier to spot. The revisions are now 00x00y where
x is trigger (same as before A,B,C are TPS and D is switch) Switch code is unchanged but untested.
y is the release version

Dropbox - UPDATE_C00A00B.EBL
Dropbox - UPDATE_C00B00B.EBL
Dropbox - UPDATE_C00C00B.EBL
Dropbox - UPDATE_C00D00B.EBL
Click to expand...
 
#512
lolachampcar said:
First pass at RingBuf Logger.
One second pre-trigger.
One second post trigger.
Both can be adjusted.

There is a 7/100ths loss of data (seven samples) when transitioning from pre to post trigger data.
Here is an example with a 25% TPS trigger.
Time TPS Speed R_Tq F_Tq BatV BatI R_RPM AWD
0093.52 024.8 +011.70 +094.9 +019.7 360.78 -0083.7 +01415
0093.53 024.8 +011.75 +096.2 +010.8 360.65 -0083.5 +01409
0093.61 025.6 +012.10 +105.2 +002.0 360.28 -0093.0 +01455
0093.62 025.6 +012.10 +105.8 +002.2 360.02 -0098.1 +01471
Click to expand...
I've been finding that simple pedal press launches have consistently had slightly better logger numbers than Launch Mode but the data only begins with the pedal press. You new ring buffer's pre-trigger captured data would be interesting to examine with spontaneous short launches on various surfaces, but it looks like the missing seven samples would come at exactly the wrong time.
 
#513
Keeping an open section at the start of each logging session so the ring buffer can be post processed is possible. It was just turning out to be such a pita that I pushed it off until I could get a first pass out the door.

Also found a bug in the switch code and have updated the file in my drop box. If you pulled the switch code update, please discard it and grab the latest (still same file name).
Dropbox - UPDATE_C00D00B.EBL
 
#514
lolachampcar said:
...Also found a bug in the switch code and have updated the file in my drop box. If you pulled the switch code update, please discard it and grab the latest (still same file name).
Dropbox - UPDATE_C00D00B.EBL
Click to expand...
Bill - Since your FW uses the toggle switch to select between logging Battery Health data and logging Performance data, how does your C00D00B version use the toggle switch to start/stop Performance logging? Does it alternate between logging each type of data?
 
#516
FYI fellow loggers - My bad. The latest Excel Launch Template (modified March 13) in Google Docs: Templates has a bug causing it to indicate erroneous (very long) 0-60 MPH times only on some runs. Everything else, including the virtual Timeslip numbers are OK. I'm attempting to fix that 0-60 formula and I'll post when I do.
 
#518
MikeBur said:
LOL, guess you couldn't wait until the track today? :)

Great, you got the charts up and the data is logging good. Now when should we expect the track data? :p
Click to expand...
Bad news: I dropped the ball on logging at ORP. Only the 4th session was viable and by then I was at 1/2 battery so it wasn't really compelling. (Also I forgot to flip the switch. :()

Good news: I'll be at the Ridge this weekend, so hopefully I can get some data then.
 
#520
brianman said:
Bad news: I dropped the ball on logging at ORP. Only the 4th session was viable and by then I was at 1/2 battery so it wasn't really compelling. (Also I forgot to flip the switch. :()

Good news: I'll be at the Ridge this weekend, so hopefully I can get some data then.
Click to expand...
D'Oh! You mean you weren't concentrating on the switch while driving on a track!? ;-)

Safety first for sure. Need to understand more about all these track days you're doing. Thought it was still a bit early?
 
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