Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > 2014+ Jeep Grand Cherokee Ecodiesel 3.0

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 08-29-2014, 12:29 PM
Rumline's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Dec 2011
Location: Los Angeles, CA
Posts: 260
Thanks: 67
Thanked 35 Times in 23 Posts
Rep Power: 1470
Rumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond repute
Managing turbo response when offroad

I've taken my car offroad several times since picking it up in May, and it's been great. Previously I had a '12 WK2 Hemi so I'm pretty familiar with the QuadraTrac/SelecTerrain system etc. I definitely notice the difference with this car having a turbo. Last month however I realized that it can be a double-edged sword; it's difficult to drive slowly when you're in rocky terrain. I was wondering if people have any tips for how to manipulate the car to try to minimize any surging caused by the turbo. Before you say "use SelecSpeed!" read my story below.

I was in low-range at OR1 height driving up a road that was mostly loose rock/talus. Think gravel but each piece of gravel is between golf ball and baseball size. I've driven across small-ish talus fields before, but this was my first time on a road of this kind. As I drove over the rocks they would often shift, which would cause the car to slip slightly/rock to one side, but there were also larger boulders semi-submerged in the talus which would not move. So the ride was what I consider extremely bumpy. I had to be at OR1 to clear the boulders. The tires would often run into these boulders and need some extra throttle to make it over them. But when I gave it enough throttle to make it over, the turbo would spool up and launch me over the rock. Even though I then removed my foot from the gas, the momentum would make the car go too fast for the suspension to handle the uneven terrain and the body would rock side to side very harshly.

I did engage SelecSpeed several times, both going uphill and downhill, and the resulting ride was worse than me driving manually. The automated wheel-braking was fairly aggressive and the car would lurch what seemed like every time they were applied. I think the algorithm was not able to maintain a constant speed like it wants to do and couldn't really handle that situation. The feature works brilliantly on smoother terrain.

Upon reflecting on the experience later, I thought that the car would have driven better if it started in second gear so I wouldn't get quite so much torque out of it. Or maybe I shouldn't have been in low range?

Any suggestions on how to achieve a more gradual torque delivery in these cars?
__________________

__________________

2014 Overland Ecodiesel 4x4 - Adv. Tech - ORA2

Reply With Quote
  #2  
Old 08-30-2014, 10:14 PM
Member
 
Join Date: May 2014
Posts: 51
Thanks: 1
Thanked 4 Times in 3 Posts
Rep Power: 286
macrophyllum is on a distinguished road
Re: Managing turbo response when offroad

I'd be curious to hear what others say. I'm hoping I can get better at driving over rocks in 4 low with additional practice.
__________________

__________________
Reply With Quote
  #3  
Old 08-30-2014, 11:20 PM
Member
 
Join Date: Sep 2013
Posts: 412
Thanks: 24
Thanked 31 Times in 27 Posts
Rep Power: 1143
Roadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond reputeRoadkill has a reputation beyond repute
Re: Managing turbo response when offroad

Damn. I wonder if there will ever be any aftermarket hybrid (aka "electrically-assisted") turbochargers available for our platform. Basically no turbo lag to deal with at that point.

Sometimes I do the "power brake turbo launch" to deliver smooth power at 0 rpm (great for avoiding turbo lag while traversing intersections). You might try that.

However, a few days of doing this semi-regularly caused my EcoDiesel to pop its first active regen warning. My guess is that it's basically rolling coal right into the DPF when you do that. Heh.
__________________
Reply With Quote
  #4  
Old 08-31-2014, 03:51 PM
lp967's Avatar
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Aug 2011
Location: Arlington, Texas
Posts: 53
Thanks: 1
Thanked 3 Times in 2 Posts
Rep Power: 1285
lp967 is on a distinguished road
Re: Managing turbo response when offroad

I recently did a lot of 4lo driving in rocky terrain up in Colorado a few weeks ago. I know what you are talking about with the surging. I used 2nd and third gear for 90% of the climbing which kept the RPMs around the 2000-2500 range. That kept things pretty smooth. I would only use 1st gear when it got real steep or hairy and I needed to go extra slow. I found that if I left the transmission in the automatic drive the shift points were off and it was very rough so I always shifted manually in the rocks.

Another thing that helps keep things smooth is using two feet for the brake and gas. Keep pressure on the brake while applying the gas the letting off the brake slowly to get it moving over the obstacle. It takes a little getting use to but helps a lot when driving an automatic off road.
__________________
Reply With Quote
The Following User Says Thank You to lp967 For This Useful Post:
  #5  
Old 08-31-2014, 06:37 PM
Benn0's Avatar
Premium Member
 
Join Date: Oct 2013
Location: Brisbane, Australia
Posts: 1,125
Thanks: 25
Thanked 79 Times in 69 Posts
Rep Power: 16284
Benn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond repute
Garage
Re: Managing turbo response when offroad

I thought selec-speed wasn't available on the diesel, only hill descent?

I haven't done much rock crawling yet in the grand, but I'd be trying 4lo and manual shift, as suggested above.
__________________
MY14 Grand Cherokee LTD CRD - Deep Cherry Red
Status: Delivered 6th May 2014 - Mod time
Reply With Quote
  #6  
Old 08-31-2014, 09:29 PM
Zhe Wiz's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jun 2013
Location: Central NY - Ithaca
Posts: 455
Thanks: 81
Thanked 62 Times in 39 Posts
Rep Power: 2316
Zhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond reputeZhe Wiz has a reputation beyond repute
Re: Managing turbo response when offroad

Quote:
Originally Posted by Benn0 View Post
I thought selec-speed wasn't available on the diesel, only hill descent?

I haven't done much rock crawling yet in the grand, but I'd be trying 4lo and manual shift, as suggested above.
It was a late addition to the diesels. My 2/14/14 build did NOT have it. My 4/14/14 order DID have it.
__________________
Zhe Wiz

Reply With Quote
  #7  
Old 08-31-2014, 09:51 PM
Benn0's Avatar
Premium Member
 
Join Date: Oct 2013
Location: Brisbane, Australia
Posts: 1,125
Thanks: 25
Thanked 79 Times in 69 Posts
Rep Power: 16284
Benn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond reputeBenn0 has a reputation beyond repute
Garage
Re: Managing turbo response when offroad

Ahhh, mine is a Feb build.... doesn't have it.
__________________
MY14 Grand Cherokee LTD CRD - Deep Cherry Red
Status: Delivered 6th May 2014 - Mod time
Reply With Quote
  #8  
Old 09-02-2014, 09:28 PM
Member
 
Join Date: May 2014
Posts: 51
Thanks: 1
Thanked 4 Times in 3 Posts
Rep Power: 286
macrophyllum is on a distinguished road
Re: Managing turbo response when offroad

How do I know if mine has it? I don't know when it was built.
__________________
Reply With Quote
  #9  
Old 09-02-2014, 09:43 PM
netboy's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Aug 2013
Location: CT
Posts: 311
Thanks: 36
Thanked 68 Times in 37 Posts
Rep Power: 1000
netboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond repute
Re: Managing turbo response when offroad

Quote:
Originally Posted by macrophyllum View Post
How do I know if mine has it? I don't know when it was built.
Look at your Selec-Terrain control panel (the little panel with the snow-sand... selector switch). The lower left button has an icon of a Jeep. If the icon is a tilted Jeep reclining down, you've got Hill-Descent. If the icon is a horizontal Jeep (not tilted) you've got Selec-Speed.
__________________
Summit 4x4 Diesel, Black / Jeep Brown.
Reply With Quote
  #10  
Old 09-02-2014, 10:05 PM
netboy's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Aug 2013
Location: CT
Posts: 311
Thanks: 36
Thanked 68 Times in 37 Posts
Rep Power: 1000
netboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond reputenetboy has a reputation beyond repute
Re: Managing turbo response when offroad

Quote:
Originally Posted by macrophyllum View Post
I don't know when it was built.
You can find your build-date by looking at the build sticker on the front driver side door (sticker is on the door, not the frame). The top left of the label will have "Date of MFR" which is the month and year of the build. The lower right side of the label will have "MDH" which is the Month-Day-Hour. So if Date-of-MFR is 11-13 and MDH is 112521, your JGC was built on November 25th 2013 and left the line at 9PM).
__________________
Summit 4x4 Diesel, Black / Jeep Brown.
Reply With Quote
  #11  
Old 09-04-2014, 01:01 PM
Rumline's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Dec 2011
Location: Los Angeles, CA
Posts: 260
Thanks: 67
Thanked 35 Times in 23 Posts
Rep Power: 1470
Rumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond reputeRumline has a reputation beyond repute
Re: Managing turbo response when offroad

Quote:
Originally Posted by lp967 View Post
I found that if I left the transmission in the automatic drive the shift points were off and it was very rough so I always shifted manually in the rocks.
Thanks for your response. I have tried manually shifting up using the paddle shifters before but it wouldn't seem to let me unless I was already going fast enough for 2nd gear. I'm going to try this in the parking lot after work today.
__________________

2014 Overland Ecodiesel 4x4 - Adv. Tech - ORA2

Reply With Quote
  #12  
Old 09-04-2014, 01:29 PM
lp967's Avatar
Member
My Jeep: 2014 3.0L WK2
 
Join Date: Aug 2011
Location: Arlington, Texas
Posts: 53
Thanks: 1
Thanked 3 Times in 2 Posts
Rep Power: 1285
lp967 is on a distinguished road
Re: Managing turbo response when offroad

Quote:
Originally Posted by Rumline View Post
Thanks for your response. I have tried manually shifting up using the paddle shifters before but it wouldn't seem to let me unless I was already going fast enough for 2nd gear. I'm going to try this in the parking lot after work today.

I would not recommend trying it on pavement. In 4low it is going to put a lot of bind on transfer case and axles. I would find some gravel, grass or a more forgiving surface to try it on.
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
** Tip ** Managing brake dust VerbalKint Grand Cherokee SRT - WK2 11 05-23-2013 12:50 PM
First WK used for emergency response????? Crestwood1001 Interior/Exterior/Visual 48 01-21-2012 01:32 PM
Can I go Offroad without the Offroad package? ucla95 Suspension/Driveline/Brakes/Wheels/Tires 13 12-19-2011 11:56 AM
Throttle response. ILSMKU Grand Cherokee - WK2 - 5 09-29-2010 07:14 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:29 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by Chrysler Group LLC.