Selec Terrain mode power distribution - Page 10 - 2014+ Jeep Cherokee Forums
User Tag List

 16Likes
Reply
 
LinkBack Thread Tools
post #91 of 95 (permalink) Old 04-17-2017, 04:40 PM
Member
 
Join Date: Jan 2017
Posts: 31
Yeah, I thought it was a really good thread and that a different explanation of things could help.
iwfur25 is offline  
Sponsored Links
Advertisement
 
post #92 of 95 (permalink) Old 04-18-2017, 12:05 AM
Forum Elder
 
Array's Avatar
 
Join Date: Jan 2014
Location: SE Michigan
Posts: 4,456
I've learned from this thread. This last round led me to look up Ackerman Steering. Reason is I visualized the rear wheels carving a larger arc and thus turning faster than the front wheels through a turn, and learned the opposite to be true. Don't laugh. Sometimes it's hard living in my head.

So going back to Jeep's comment reported in post #67 of this thread:

"The 2014 Jeep Cherokee utilizes its active 4WD clutch to influence the amount of torque reacted by the rear axle, as the actual amount is a function of the clutch, the friction at the tires and the center of the vehicle's mass."

And...

"When in Sport Mode, the power is variably split between the front and rear wheels with a rear wheel biased 40/60 split."

Focusing on the case of the KL in Sport Mode and moving through a curve.

- First, because it's in Sport Mode, the dance has been completed where the RDM/TTD spun up the drive shaft to rear wheel speed and the PTU locked the drive shaft to the transmission's output.

- Assuming the KL is driven in a straight line and there is good traction at all four wheels, the TTD's clutch has probably been opened so the KL is in FWD but turning the drive shaft.

- As the KL enters a turn at speed, the traction system's yaw sensor measures the movement of the vehicle's center of mass to the outside of the turn.

- A signal is sent to the TTD's controller telling it to pulse the clutch at a certain rate depending on the measure of yaw. The greater the yaw, the faster the rate of TTD pulsing up to and including a lock state.

- Since the front wheels are turning slightly faster than the rear wheels, the TTD's pulsing creates a twisting force through the rear differential thus applying more torque to the rear wheels.

That's my guess for the day.

2015 White/Black Limited | 3.2-L V6 | Active Drive II | Tech Grp | Lux Grp | Trailer Tow Grp | SafetyTec | Uconect 8.4AN | 9 Speakers | Tonneau Cover | Born 09-06-14 : (( (( (( (( (( (( (( :
Array is offline  
post #93 of 95 (permalink) Old 04-18-2017, 12:38 PM
Member
 
Join Date: Aug 2016
Posts: 49
Just a driver's experience with sport mode, it is quite different from auto mode. The shift points are definitely higher and stays in lower gears longer. In auto mode, the revs drop to 1500rpm but in sport mode the revs stay around 3000rpm. Around town, top gear is 4th instead of 7 or 8. Very interesting change of pace.

Haven't had a chance to try sport mode on twisty roads but that's next.
fumbling is offline  
 
post #94 of 95 (permalink) Old 04-18-2017, 12:53 PM
Enthusiast Member
 
Join Date: Mar 2015
Location: Pittsburgh
Posts: 169
^^^ I wish we could keep the rear bias 4wd from SPORT mode with normal shift schedule of AUTO.

2015 Trailhawk V-6: EcoGreen/Black, Conv Pkg, Tow Pkg, Cold Weather, NAV, CD, Hood Decal
Subscribe to my YouTube Chan for Jeep Vids and more! https://www.youtube.com/c/CarGuy11C7
Instagram@carguy_11
JeepKL is offline  
post #95 of 95 (permalink) Old 04-21-2017, 07:55 AM
Enthusiast Member
 
Join Date: Mar 2015
Location: Pittsburgh
Posts: 169
Someone commented on one of my YouTube videos that turning off traction control engages the rear axel full time. I tried it today and I believe it works! So you can retain the normal shift program while it being in 4wd! Anyone else try this and is there any mention of this in the above technical data?

2015 Trailhawk V-6: EcoGreen/Black, Conv Pkg, Tow Pkg, Cold Weather, NAV, CD, Hood Decal
Subscribe to my YouTube Chan for Jeep Vids and more! https://www.youtube.com/c/CarGuy11C7
Instagram@carguy_11
JeepKL is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the 2014+ Jeep Cherokee Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



  Similar Threads
Thread Thread Starter Forum Replies Last Post
Jeep : Grand Cherokee Overland Overland SUV 5.7L Sunroof NAV Power Steering Power Doo Jeep Cherokee Parts Jeep Cherokee eBay Classifieds 0 02-21-2014 08:40 PM
Jeep : Grand Cherokee SRT-8 SRT-8 Certified 6.4L V-8 NAV Power Steering Power Door Lo Jeep Cherokee Parts Jeep Cherokee eBay Classifieds 0 02-12-2014 12:50 PM
Selec-Terrain knob for Limited Wildturkey 2014+ Jeep Cherokee General Discussion 6 01-24-2014 02:45 PM
Selec Terrain Mode testing *video* Tyler-98-W68 Off-Road 8 12-29-2013 09:15 AM
Selec-Terrain Seguerski 2014+ Jeep Cherokee General Discussion 5 12-06-2013 11:56 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On