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-   -   Detailed explanation of D/S and Select-Track control knob settings ? (http://www.jeepgarage.org/f97/detailed-explanation-of-d-s-and-select-track-control-knob-settings-71461.html)

DarkHue 02-09-2014 07:28 AM

Detailed explanation of D/S and Select-Track control knob settings ?
 
I read the info available regarding Drive mode and Sport mode on the stick shift, along with the Select-Track control knob for suspension settings. But I really want a thorough, detailed explanation of how these different settings work.

For example, driving on Sport via the Select-Track control knob while having the stick shift on D. What does this actually do ?

I'd be grateful if you can spend a few mins of your time to explain these, I'm sure others will benefit as well :)

Thanks !

Scottina06 02-09-2014 08:02 AM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
try here and then ill answer any more questions you may have


Great Eight: The Grand Cherokee SRT® receives an 8-speed transmission for 2014. | driveSRT

DarkHue 02-09-2014 09:20 AM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
Thank you for the link.

So from what I understand :

1- Changing between D and S on the gear shifter provides different upward/downward shifting speeds; Drive gives a more comfortable shifting while Sports provides more aggressive shifts.

2- Using the Knob to change between Auto/Sport/Track changes how stiff the car is, along with modifying traction control intrusion.

Did I get 1 and 2 correct so far ?

Question : Is the car's suspension the only thing that stiffens up when using the knob ? Or is there more to it ?

phillysrt 02-09-2014 05:40 PM

Quote:

Originally Posted by DarkHue (Post 972908)
Thank you for the link. So from what I understand : 1- Changing between D and S on the gear shifter provides different upward/downward shifting speeds; Drive gives a more comfortable shifting while Sports provides more aggressive shifts. 2- Using the Knob to change between Auto/Sport/Track changes how stiff the car is, along with modifying traction control intrusion. Did I get 1 and 2 correct so far ? Question : Is the car's suspension the only thing that stiffens up when using the knob ? Or is there more to it ?

There's way more to when using the knob.

Stiffness, torque ratio, matched rpm downshifts,

Just turn the knob and your feel and see the difference in ride quality and handling

Scottina06 02-09-2014 08:34 PM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
I think SRTR claims there are 99 different tuning calibrations using the select knob etc.

DarkHue 02-09-2014 11:08 PM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
Quote:

Originally Posted by phillysrt (Post 973090)
There's way more to when using the knob.

Stiffness, torque ratio, matched rpm downshifts,

Just turn the knob and your feel and see the difference in ride quality and handling

Can you point me to a source that explains this technically ? I really want to know EXACTLY how the car behaves differently, call it trying to have a deeper bond with the beast.

Scottina06 02-09-2014 11:33 PM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
drivesrt.com that I posted earlier has the most info you will find on that subject. guess someof it could be "top secret".....not sure though.

I do know that it disables nannies...like traction control etc. or enables it. like snow mode for instance....is 50/50 tq split front to rear and enables or makes the some of the safety systems more apparent. Starts in 2nd gear...probably pre-empts the braking system, tones down shift curves, limits revs, shifts at lower rpms, limits tq., activate safety systems earlier to help prevent accidents. etc etc. Where as track is probably the total polar opposite....where EVERYTHING is tuned for performance as the highest priority.

We have a resident SRT 'expert" here that I will call upon to answer this if he "can"

DarkHue 02-09-2014 11:54 PM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
Quote:

Originally Posted by Scottina06 (Post 973246)
drivesrt.com that I posted earlier has the most info you will find on that subject. guess someof it could be "top secret".....not sure though.

We have a resident SRT 'expert" here that I will call upon to answer this if he "can"


Thank you for replying. Yep I gave it a read and the points (1 and 2) I mentioned above are the results of my understanding until now. But I want more.

Sports mode on the knob reduces traction control intrusion, while Track mode disables that fully. Does that mean Sport mode is safer at sharp bends (on the road and not the track) ? But then track mode provides a stiffer suspension, which means chance of rolling over is reduced, yet traction is off, which means it might skid when turning at a high speed. Right ?
What about launching without LC, Sport mode on the knob + gear should provide a faster launch because of TC. Yet Track mode has optimal shifting modes which should provide a faster launch from 0kmh, but then again, it might lose a bit of precious milliseconds when it wheel spins due to no traction control !!

This is why I want to read more technical data about the gear and knob, I want to really know what goes on so that I can make the most out of this monster.

Scottina06 02-10-2014 12:09 AM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
well...for instance....sports mode is 60/40 rear bias...whereas track is 70/30 rear bias. I think any traction loss would be due to other factors...like tires, conditions etc. I would also guess that tq control is more apparent in sport mode...therefore limiting the tq to be used....making the jeep slower. Most Jeeps I have driven and my own personal jeep is A LOT faster IMHO in track. Everything in track is tuned for ultimate performance....even the take off rpms in track launch control. Jeep from what I know....has tuned the Jeep to perform better in track mode.....all areas.

DarkHue 02-11-2014 02:55 AM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
Quote:

Originally Posted by Scottina06 (Post 973265)
well...for instance....sports mode is 60/40 rear bias...whereas track is 70/30 rear bias. I think any traction loss would be due to other factors...like tires, conditions etc. I would also guess that tq control is more apparent in sport mode...therefore limiting the tq to be used....making the jeep slower. Most Jeeps I have driven and my own personal jeep is A LOT faster IMHO in track. Everything in track is tuned for ultimate performance....even the take off rpms in track launch control. Jeep from what I know....has tuned the Jeep to perform better in track mode.....all areas.

I'm assuming "tq control" is torque control ?
Ah I see, well it's weird that I get faster times with Sports mode rather than Track.
What's the username of the engineer here ? I would like to PM him about this for technical details !

Scottina06 02-11-2014 04:15 AM

Sorry....can't tell ya that. He Will Respond though

Mr GCSRT8 02-11-2014 08:54 AM

Re: Detailed explanation of D/S and Select-Track control knob settings ?
 
Dark Hue, Im going to try to take you through a basic understanding of the function of the Shifter and the Select Track knob in an attempt to answer your questions.
Let's start with the Shifter: The D/S on the shifter solely controls the Transmission Shift schedule. When in Auto on the Select Track knob, pulling the shifter back will change the transmission calibration to a more aggressive shift schedule. This shift schedule will be very close to the Select Track Sport mode shift schedule. When the Select Track knob is in Sport or Track the cluster will indicate that the transmission is in Sport "S" shifting, although the cluster indication is the same in Sport and Track mode the Transmission calibration is different. Pulling the shifter back in Sport or Track will put the transmission in standard drive "D this is the Auto mode drive shift calibration.

Now let's review the Select Track Knob. Each mode has a unique calibration for the following functions:
ESC - Electronic Stability Control/Traction Control
ADS - Active Damping Suspension
Gear Start - only modified in ECO or Snow Mode
Transmission/Overdrive Shift
Transfer Case
Electronic Limited Slip Differential
PCM -Throttle Control
MDS - Cylinder deactivation
Cluster messages

AUTO: All systems set to standard (suspension adaptive)

SPORT:
ESC set to sport (allows more yaw then Auto)/TC ON
ADS Standard Compression/Firm Rebound (adaptive)
Sport Transmission Shift Schedule
T/Case torque split - 65R/35F
ELSD - sport calibration
PCM - Sport
MDS - Off

TRACK:
ESC set to Track (Allows more yaw then Sport)/TC off
Note: ESC and TC can be disabled in track
ADS full Firm Compression and Rebound (Not Adaptive)
Track Transmission Shift Schedule
T/Case torque split 70R/30F
ELSD - track calibration
PCM - Track
MDS - Off

SNOW:
ESC - Most Aggressive setting
ADS - Same as auto (Adaptive)
Transmission - 2nd gears starts
T/Case 50/50 torque split
ELSD - Snow Calibration
PCM - Snow
MDS - Active

TOW:
ESC - Tow Calibration
ADS - Standard compression/Full firm Rebound (Active to reduce vehicle vertical motion)
Transmission - Unique Tow calibration
T/case 50/50 torque split
ELSD - tow calibration
PCM - Tow calibration
MDS - Active

LAUNCH:
Launch Mode adjust everything in the vehicle from nose to tail for maximum acceleration. This is an engineered launch that has had extensive testing. It is designed to give the best acceleration and most consistent performance.


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