do you know what your throttle is doing? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

7thgear · 06-18-2014, 09:49 PM

nerding over some data I pulled from my last autocross and compared it to a friend's

top is pedal position and bottom is throttle position

"what does this mean?"

given that this graph represents 350 meters of track, there is a measurable latency between when you're on the gas and when the throttle reacts

in the case of my friend, who at times stabbed the gas, the response was almost nothing..

BRING BACK CALBES!!

1st graph is me, 2nd graph is my friend

D K · 06-19-2014, 02:22 AM

Was the traction control on?

hmong337 · 06-19-2014, 03:15 AM

I'm old school and will always be. After 1 year of owning this car, I still hate the dbw!

CABLES FTMFW!!!!

CSG Mike · 06-19-2014, 05:09 AM

What was the status of VSC?

7thgear · 06-19-2014, 08:39 AM

Quote:

Originally Posted by CSG Mike

What was the status of VSC?

Quote:

Originally Posted by D K

Was the traction control on?

both tc and vsc was disabled via the 5-second press (not ready for the pedal dance quite yet)

in my car anyway... i'll ask my friend, but he's also on top of his game so I doubt he left em on.

interstingly enough our net times were the same for this configuration (with me 0.4s faster)

renfield90 · 06-19-2014, 10:51 AM

Quote:

Originally Posted by D K

Was the traction control on?

Quote:

Originally Posted by CSG Mike

What was the status of VSC?

7thgear, It sure looks like TC was cutting in - see the drop in throttle position during the first long sustained 100% pedal section. Unless those graphs are reversed...then we have a safety problem (or a performance enhancement, depending on your view).

7thgear · 06-19-2014, 10:57 AM

Quote:

Originally Posted by renfield90

7thgear, It sure looks like TC was cutting in - see the drop in throttle position during the first long sustained 100% pedal section.

I'm not seeing what you're seeing.

there are two graphs, the blue and red, they represent different drivers.

within each graph, however, Top is pedal, lower is throttle, both graphs are aligned (id overlap them but I can figure out how to change colours for same-lap/car but different graphs)

AustinTX · 06-19-2014, 11:41 AM

Seems like the differences are mostly the smoothing of transient inputs, for example the missing blip in the center of the lower graph. This difference may be a physical constraint of the motor used to drive the butterfly, but it is more likely an effect of the ECU controlling transient inputs to protect the engine. Both graphs show little gas pedal modulation, but the lower graph shows some extremely aggressive throttle input. Tip-in enrichment and timing are probably going crazy on the lower graph. Time to drive smoother

sluflyer06 · 06-19-2014, 11:45 AM

Quote:

Originally Posted by hmong337

I'm old school and will always be. After 1 year of owning this car, I still hate the dbw!

CABLES FTMFW!!!!

What were you driving before, basically all cars have gone DBW years and years ago. I mean by WRX was 8 model years older than my BRZ and it already had DBW.

7thgear · 06-19-2014, 11:50 AM

Quote:

Originally Posted by AustinTX

Both graphs show little gas pedal modulation, d

so modulating the throttle for over 80% of a run is little modulation?

I agree that my friend is more stabby with his gas, but he is trying to get the car to rotate by powering through turns while I'm trying to ensure that it doesn't plow through the turn.

given that our end times were so close together, the real point to take away is that I need to be more aggressive and he needs to dial it back a little.

hmong337 · 06-19-2014, 11:59 AM

Quote:

Originally Posted by sluflyer06

What were you driving before, basically all cars have gone DBW years and years ago. I mean by WRX was 8 model years older than my BRZ and it already had DBW.

Everything 90's. My FRS is my first actual newer car.

Don't you guys miss revving the car from under the hood? Haha.

AustinTX · 06-19-2014, 12:40 PM

Quote:

Originally Posted by 7thgear

so modulating the throttle for over 80% of a run is little modulation?

True, the upper one doesn't look bad at all considering this is still a momentum car.

CSG Mike · 06-19-2014, 01:17 PM

Interesting. I use stabs to rotate the car too, but I've never had the car flat out ignore it like that before.

celica73 · 06-19-2014, 01:33 PM

what is the data sampling rate?

06-18-2014, 09:49 PM	#1
7thgear i'm sorry, what? Join Date: Jan 2012 Drives: Canada Location: I rock a beat harder than you can beat it with rocks Posts: 4,399 Thanks: 357 Thanked 2,508 Times in 1,268 Posts Mentioned: 40 Post(s) Tagged: 3 Thread(s)	do you know what your throttle is doing? nerding over some data I pulled from my last autocross and compared it to a friend's top is pedal position and bottom is throttle position "what does this mean?" given that this graph represents 350 meters of track, there is a measurable latency between when you're on the gas and when the throttle reacts in the case of my friend, who at times stabbed the gas, the response was almost nothing.. BRING BACK CALBES!! 1st graph is me, 2nd graph is my friend __________________ don't you think if I was wrong, I'd know it? Last edited by 7thgear; 06-18-2014 at 10:07 PM.

06-19-2014, 03:15 AM	#3
hmong337 Emperor JDM Join Date: Jun 2013 Drives: '91 MR2 Gen3 3SGTE, '13 FRS Location: Onterrible, Canada Posts: 1,750 Thanks: 3,498 Thanked 909 Times in 495 Posts Mentioned: 20 Post(s) Tagged: 3 Thread(s)	I'm old school and will always be. After 1 year of owning this car, I still hate the dbw! CABLES FTMFW!!!! __________________

06-19-2014, 11:41 AM	#8
AustinTX Pawn in game of life Join Date: Nov 2013 Drives: 19 STX BRZzz Location: ATX Posts: 262 Thanks: 33 Thanked 65 Times in 42 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	Seems like the differences are mostly the smoothing of transient inputs, for example the missing blip in the center of the lower graph. This difference may be a physical constraint of the motor used to drive the butterfly, but it is more likely an effect of the ECU controlling transient inputs to protect the engine. Both graphs show little gas pedal modulation, but the lower graph shows some extremely aggressive throttle input. Tip-in enrichment and timing are probably going crazy on the lower graph. Time to drive smoother __________________ Autocross nut

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06-19-2014, 02:22 AM	#2
D K Stig's dark passenger Join Date: Dec 2013 Drives: FR-S Location: I work abroad Posts: 724 Thanks: 60 Thanked 316 Times in 186 Posts Mentioned: 20 Post(s) Tagged: 1 Thread(s)	Was the traction control on?

06-19-2014, 05:09 AM	#4
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,562 Thanks: 8,942 Thanked 14,211 Times in 6,854 Posts Mentioned: 970 Post(s) Tagged: 14 Thread(s)	What was the status of VSC?

06-19-2014, 01:17 PM	#13
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,562 Thanks: 8,942 Thanked 14,211 Times in 6,854 Posts Mentioned: 970 Post(s) Tagged: 14 Thread(s)	Interesting. I use stabs to rotate the car too, but I've never had the car flat out ignore it like that before.

06-19-2014, 01:33 PM	#14
celica73 Senior Member Join Date: Jun 2012 Drives: '13 BRZ / '11 Outback / '06 Tundra Location: Durham NC Posts: 510 Thanks: 6 Thanked 155 Times in 104 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	what is the data sampling rate?

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