1LE - Driving Modes/PTM demystified - Page 7

TrackClub · 06-26-2017, 10:17 AM

Wise choice sir ^^

TrackClub · 06-29-2017, 12:15 AM

Went back and tested 3 modes now that I feel pretty comfy with the car. Here's my impressions:

PTM Sport 1: seems the safest choice, as it retains both the Stabilitrak and TC, but at an expense of some pace IMO. The car felt a bit restricted on both rotation and exits in comparison to the next 2.
But one can still drive the car very fast in this mode - just proly not as fast the the next two.

Comp Mode (Track mode then press TC once): retains Stabilitrak but shuts off TC - it was faster than the one above and felt a lot less restrictive but one needs to modulate power on exits as 100% is available. The car still felt somewhat restricted on rotation, but overall pace was faster. Note the rear feels looser as you have access to full power with your foot. Since the car has good torque, it can overcome Stabilitrak easily and wag the tail (and/or spin) if you decide to drive it like a hooligan.
This mode is an old "advanced" nanny mode, before GM introduced PTM and is defo more "advanced" than PTM Sport 1 (IMO).

PTM Race - No Stabilitrak but TC remains on, albeit in the least restrictive fashion as compared to Sport 1 or 2. The car rotates in a fantastic fashion and is easily modulated with throttle. But if you over do it there is no Stabilitrak to save the day. Exits feel very composed yet fast, as TC works in concerts with E-LSD in very seamless fashion. This is the fastest mode save for "all off" (albeit GM Engineers will argue Race is faster if used properly - see my OP), but one has to have knowledge and experience regarding proper "weight transfer" principles (balance/traction) as the rear will come around if you don't, or make a mistake and unbalance a car.
No, miracles don't happen and trying to corner on 1 front wheel will always result in a spin

Use at own risk, read the official manual, get proper instruction, etc. Results may vary based on a driver, type of track, etc. When in doubt, turn nannies up: it is no fun going home on a flat bed. Cheers!

EDIT: cleaned up original post

TrackClub · 06-29-2017, 11:34 AM

updated my OP with PTM info as presented by GM engineers, for each mode. VERY informative and must read, including how to properly use steering angles to get most out of the PTM Race setting (especially valuable to those that may experience push/understeer on exits - wink, wink, nudge, nudge

)

seanblurr · 06-29-2017, 12:00 PM

One must wonder, for how optimized PTM Race is for the given tire, how might a stickier tire affect its functionality.

TrackClub · 06-29-2017, 12:25 PM

Quote:

Originally Posted by seanblurr

One must wonder, for how optimized PTM Race is for the given tire, how might a stickier tire affect its functionality.

very good question. I believe the PTM can read the slip angles, so I think its function may very well be tire agnostic and it may just care about slip angles.
same principles would still apply tho re steering angles to "feed" info to PTM re power distribution vs slip angles allowed. which should translate to faster pace.
guessing tho

Rafal · 07-10-2017, 10:47 AM

Quote:

Originally Posted by seanblurr

One must wonder, for how optimized PTM Race is for the given tire, how might a stickier tire affect its functionality.

The only thing I would think you can optimize for a tire is a spring rate. Grip changes all the time even with the same tire like between a green track after a downpur and fully rubbered in after some competition a day before.

mjk3888 · 07-10-2017, 12:29 PM

Quote:

Originally Posted by TrackClub

very good question. I believe the PTM can read the slip angles, so I think its function may very well be tire agnostic and it may just care about slip angles.
same principles would still apply tho re steering angles to "feed" info to PTM re power distribution vs slip angles allowed. which should translate to faster pace.
guessing tho

Quote:

Originally Posted by Rafal

The only thing I would think you can optimize for a tire is a spring rate. Grip changes all the time even with the same tire like between a green track after a downpur and fully rubbered in after some competition a day before.

I don't think the tire has as big of an effect as most are thinking. One of the fastest C7 Z06's at the last national level SCCA event was running on non stock tires and he was running in RACE mode PTM! He won the SS class over some very stiff competition including several C7 Grand Sports and the new Acura NSX.

TrackClub · 07-11-2017, 07:59 PM

Ya I don't think tire type has much effect on PTM or Comp Mode as they work based on yaw/slip angles and traction levels as far as I can tell. So clearly a stickier tire will simply produce more pace.

thescreensavers · 07-15-2017, 10:29 AM

More infor on eLSD modes

Quote:

eLSD Modes

eLSD modes change automatically when the traction control button is pressed as follows:

– Mode 1: The standard mode when the vehicle is started. Emphasis is on vehicle stability. Also used in PTM wet mode.
– Mode 2: Engaged when both TCS and StabiliTrak® are turned OFF. Provides more nimble corner turn-in, and is biased for better traction out of corners.
– Mode 3: Engaged when PTM is engaged in Dry, Sport 1 & 2 and Race Modes. Nimble calibration with similar functionality as eLSD Mode 2, however it is integrated to work with PTM.
– Mode 4: Engaged when TCS is selected OFF, but StabiliTrak® remains ON. Vehicle stability is still the priority, while allowing for optimized traction out of corners.

eLSD and Wheel Slip

The upper eLSD display indicates the eLSD clutch locking percentage. The lower wheel slip display indicates the rear tire slip compared to the speed of the front tires.

TrackClub · 07-15-2017, 06:43 PM

Thanks for posting these. The same info is in the manual but good to have it all together nevertheless. Cheers!

TrackClub · 08-30-2017, 07:41 PM

cleaned up and updated by OP. my thanks to SeanBlurr for "motivating" me via another thread

JayhawkSS1LE · 09-02-2017, 06:31 AM

With all the options and combinations what is the best to use to achieve the best 0-60 times? lol.
Turning all the nannies off (hold for 5ish seconds) allows for to much wheel spin. So I am assuming using launch control with Sport1 or Sport2 or Race?

Suggestions?

TrackClub · 09-02-2017, 06:54 AM

Quote:

Originally Posted by JayhawkSS1LE

With all the options and combinations what is the best to use to achieve the best 0-60 times? lol.
Turning all the nannies off (hold for 5ish seconds) allows for to much wheel spin. So I am assuming using launch control with Sport1 or Sport2 or Race?

Suggestions?

See post #4 (PTM table) which indicates that to get launch control in a "drag strip" you must be in PTM Race.

TrackClub · 09-02-2017, 07:08 AM

Added PTM table to OP so all the info is all together now.

06-29-2017, 12:15 AM	#86
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	Went back and tested 3 modes now that I feel pretty comfy with the car. Here's my impressions: PTM Sport 1: seems the safest choice, as it retains both the Stabilitrak and TC, but at an expense of some pace IMO. The car felt a bit restricted on both rotation and exits in comparison to the next 2. But one can still drive the car very fast in this mode - just proly not as fast the the next two. Comp Mode (Track mode then press TC once): retains Stabilitrak but shuts off TC - it was faster than the one above and felt a lot less restrictive but one needs to modulate power on exits as 100% is available. The car still felt somewhat restricted on rotation, but overall pace was faster. Note the rear feels looser as you have access to full power with your foot. Since the car has good torque, it can overcome Stabilitrak easily and wag the tail (and/or spin) if you decide to drive it like a hooligan. This mode is an old "advanced" nanny mode, before GM introduced PTM and is defo more "advanced" than PTM Sport 1 (IMO). PTM Race - No Stabilitrak but TC remains on, albeit in the least restrictive fashion as compared to Sport 1 or 2. The car rotates in a fantastic fashion and is easily modulated with throttle. But if you over do it there is no Stabilitrak to save the day. Exits feel very composed yet fast, as TC works in concerts with E-LSD in very seamless fashion. This is the fastest mode save for "all off" (albeit GM Engineers will argue Race is faster if used properly - see my OP), but one has to have knowledge and experience regarding proper "weight transfer" principles (balance/traction) as the rear will come around if you don't, or make a mistake and unbalance a car. No, miracles don't happen and trying to corner on 1 front wheel will always result in a spin Use at own risk, read the official manual, get proper instruction, etc. Results may vary based on a driver, type of track, etc. When in doubt, turn nannies up: it is no fun going home on a flat bed. Cheers! EDIT: cleaned up original post Last edited by TrackClub; 06-29-2017 at 11:31 AM.

06-29-2017, 12:00 PM	#88
seanblurr Drives: ZL1 1LE Join Date: Oct 2016 Location: California Posts: 1,297	One must wonder, for how optimized PTM Race is for the given tire, how might a stickier tire affect its functionality. __________________

09-02-2017, 06:31 AM	#96
JayhawkSS1LE Drives: 2017 SS 1LE Join Date: Jun 2017 Location: Woodstock, GA Posts: 200	With all the options and combinations what is the best to use to achieve the best 0-60 times? lol. Turning all the nannies off (hold for 5ish seconds) allows for to much wheel spin. So I am assuming using launch control with Sport1 or Sport2 or Race? Suggestions? __________________ 17 SS 1LE.

06-26-2017, 10:17 AM	#85
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	Wise choice sir ^^

06-29-2017, 11:34 AM	#87
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	updated my OP with PTM info as presented by GM engineers, for each mode. VERY informative and must read, including how to properly use steering angles to get most out of the PTM Race setting (especially valuable to those that may experience push/understeer on exits - wink, wink, nudge, nudge )

07-11-2017, 07:59 PM	#92
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	Ya I don't think tire type has much effect on PTM or Comp Mode as they work based on yaw/slip angles and traction levels as far as I can tell. So clearly a stickier tire will simply produce more pace.

07-15-2017, 06:43 PM	#94
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	Thanks for posting these. The same info is in the manual but good to have it all together nevertheless. Cheers!

08-30-2017, 07:41 PM	#95
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	cleaned up and updated by OP. my thanks to SeanBlurr for "motivating" me via another thread

09-02-2017, 07:08 AM	#98
TrackClub Drives: 2020 SS 1LE (previous: 2017 SS 1LE) Join Date: Mar 2012 Location: Canada, eh! Posts: 5,091	Added PTM table to OP so all the info is all together now.

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