Welcome to the North American Subaru Impreza Owners Club Saturday September 20, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Click here to visit TireRack
Brakes & Suspension Forum sponsored by The Tire Rack

Losing traction? Need new tires?
Click here to visit the NASIOC Upgrade Garage...
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Brakes, Steering & Suspension

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 07-09-2013, 09:21 PM   #1
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Question 2012 WRX, can I fully disable VDC?

I've seen a few threads that touch on this, but no clear answers.

When I turn off the VDC, I still get loss of power when trying to slide through a corner on mud. A part of the traction control, or whatever it is called, is still kicking in, preventing me from powering through the corner.

Is there a way to completely turn the system off? And then be able to restore it?

This is a WRX, so I only have on/off.

Thanks everyone.
* Registered users of the site do not see these ads.
Real Fast Travis is offline   Reply With Quote
Old 07-09-2013, 10:03 PM   #2
Dmochowski
Scooby Specialist
 
Member#: 306478
Join Date: Jan 2012
Chapter/Region: South East
Location: chattanooga, TN
Vehicle:
2012 WRX limited
305whp/360tq TSM tuned

Default

There is a thread with detailed info from a month ago or so. Basically no. Your wrx has open front and rear diff. If you did you would basically have open and spin a tire, you don't want this. You can off the system that cuts power when experiencing a lose of control which is the button.

So since there are no diffs f/r the only system controlling wheel spin is the e diff system that applies a braking force to the wheel that is spinning to act as a diff of sorts.
Dmochowski is offline   Reply With Quote
Old 07-10-2013, 12:12 AM   #3
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

I have a 2012 WRX hatch. I autocross with it. I drove it in the snow. I know how it feels with the VDC/Traction Control On and how it feels off.

Off = traction control and VDC Off. You get to take full advance of your open diffs this way (oh joy)
On = traction control and stability control is on.

With the system on I couldn't get the car to rotate in snow and I would constantly have it feel it cut power. It was definitively correcting my oversteer.
With the system off, I can spin wheels in the snow very easily. I can go sideways. Car does not try to correct. I've spun it a few times having fun in a parking lot in the snow. I also spun it once at autocross. The car did nothing to correct itself with VDC off.

TLDR: VDC OFF means OFF. (If you don't trust me, pull the ABS fuse)
redline23 is offline   Reply With Quote
Old 07-10-2013, 02:25 PM   #4
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

Quote:
Originally Posted by redline23 View Post
I have a 2012 WRX hatch. I autocross with it. I drove it in the snow. I know how it feels with the VDC/Traction Control On and how it feels off.

Off = traction control and VDC Off. You get to take full advance of your open diffs this way (oh joy)
On = traction control and stability control is on.

With the system on I couldn't get the car to rotate in snow and I would constantly have it feel it cut power. It was definitively correcting my oversteer.
With the system off, I can spin wheels in the snow very easily. I can go sideways. Car does not try to correct. I've spun it a few times having fun in a parking lot in the snow. I also spun it once at autocross. The car did nothing to correct itself with VDC off.

TLDR: VDC OFF means OFF. (If you don't trust me, pull the ABS fuse)
I had it off, and it still cut power when sliding sideways in the mud.

Why do you suggest pulling the ABS fuse? Will I get spin then?
Real Fast Travis is offline   Reply With Quote
Old 07-10-2013, 02:27 PM   #5
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

Quote:
Originally Posted by Dmochowski View Post
There is a thread with detailed info from a month ago or so. Basically no. Your wrx has open front and rear diff. If you did you would basically have open and spin a tire, you don't want this. You can off the system that cuts power when experiencing a lose of control which is the button.

So since there are no diffs f/r the only system controlling wheel spin is the e diff system that applies a braking force to the wheel that is spinning to act as a diff of sorts.
See the post below yours.

This is why I am confused, half the people say you can, half say you can't.
Real Fast Travis is offline   Reply With Quote
Old 07-10-2013, 03:44 PM   #6
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

I suggested pulling the ABS fuse as that controls the Traction Control/Stability Control and ABS. If you pull that fuse, none of those systems will work.

My argument is based on first hand experience. I can spin wheels and slide (dumping the clutch in snow will shoot the RPMs to redline and they stay up until you get traction. As you can imagine, it doesn't work very well for getting the car moving in snow. With traction control on and trying the same maneuver, the car immediately cuts power and I don't get wheel spin.

What do you notice when you say you experience power loss. Are you referring to the car not wanting accelerate as quickly as you want it to? You would feel the system cutting power if your RPMs are dropping.

The way the system is designed on the GR WRX is open front and rear diff with a viscous center diff. The open diffs work via if a wheel is spinning, all the power goes to the spinning wheel. So if you spin a wheel in the front, your other front wheel is mostly sitting there. The same behavior in the rear. The center diff will transfer power from rear to front to try to keep power where the traction is, however, since it is a viscous unit, it doesn't respond as quickly as a clutch based center diff.

What mods do you have on your car?
redline23 is offline   Reply With Quote
Old 07-10-2013, 04:01 PM   #7
Dmochowski
Scooby Specialist
 
Member#: 306478
Join Date: Jan 2012
Chapter/Region: South East
Location: chattanooga, TN
Vehicle:
2012 WRX limited
305whp/360tq TSM tuned

Default

There are two seperate traction systems in the car. Search bc no one on this thread is an expert. There was very technical info explaining that you have a system that will cut power when you lose traction, trying to keep you from having an accident or sliding off the road. This can be disabled with a button.

You have a system in your wrx that is trying to simulate having differentials front and rear by applying the brake to a wheel that is spinning in an attempt to keep both wheels spinning together. This system can not be disabled with a button, or as far as anyone was concerned at all.

The second system you would not want to turn off bc then you would have open front and rear with no control over wheel spin. I have driven enough cars with open diffs and they suck when you make power, if that was disabled and you started spinning an inside tire it would just keep spinning. The center diff could send power to the front but if you are on the gas out of a turn them you could just light up the inside front wheel. That system won't cut power and keep you from sliding the car around or going off the road ass first.

I am just regurgitating what I saw in the previous thread.
Dmochowski is offline   Reply With Quote
Old 07-10-2013, 05:17 PM   #8
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

I agree with what you are saying Dmochowski. My understanding was that the system simulating a Limited Slip via braking was accomplished by the VDC system.
redline23 is offline   Reply With Quote
Old 07-10-2013, 06:15 PM   #9
Dmochowski
Scooby Specialist
 
Member#: 306478
Join Date: Jan 2012
Chapter/Region: South East
Location: chattanooga, TN
Vehicle:
2012 WRX limited
305whp/360tq TSM tuned

Default

Quote:
Originally Posted by redline23 View Post
I agree with what you are saying Dmochowski. My understanding was that the system simulating a Limited Slip via braking was accomplished by the VDC system.
Oh yeah that's what I think most people think. I don't know the specifics but that's the jist of it.
Dmochowski is offline   Reply With Quote
Old 07-10-2013, 06:37 PM   #10
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

So I've been googling for the past hour and I've come to the conclusion that no one has any idea what the hell is going on. I'll need to take some videos of sliding the car around on snow this winter for umm scientific purposes

In the meantime here is an informative video about Outbacks and Foresters. There is a bit towards the end (3:40) about what the VDC off button does.
http://www.youtube.com/watch?feature...GnENTsoI#at=13

I'm wondering if it doesn't work the same way on the WRX since we have the same 2 lights on our dash.
redline23 is offline   Reply With Quote
Old 07-10-2013, 06:55 PM   #11
WRX boarder
Scooby Newbie
 
Member#: 328399
Join Date: Aug 2012
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2012 WRX Limited
OBP

Default

Quote:
Originally Posted by redline23 View Post
I agree with what you are saying Dmochowski. My understanding was that the system simulating a Limited Slip via braking was accomplished by the VDC system.

The big difference between the 2 systems we decided in the last discussion came down to power cut. VDC on = elsd (electronic diffs vis breaking as opposed to an actual lsd) plus power cut; VDC off= elsd and no power cut (so power loss via breaking to spinning wheel). This does not apply to the STi.
WRX boarder is offline   Reply With Quote
Old 07-10-2013, 06:57 PM   #12
WRX boarder
Scooby Newbie
 
Member#: 328399
Join Date: Aug 2012
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2012 WRX Limited
OBP

Default

Quote:
Originally Posted by redline23 View Post
So I've been googling for the past hour and I've come to the conclusion that no one has any idea what the hell is going on. I'll need to take some videos of sliding the car around on snow this winter for umm scientific purposes

In the meantime here is an informative video about Outbacks and Foresters. There is a bit towards the end (3:40) about what the VDC off button does.
http://www.youtube.com/watch?feature...GnENTsoI#at=13

I'm wondering if it doesn't work the same way on the WRX since we have the same 2 lights on our dash.
I've never noticed the AWD light on the WRX.
WRX boarder is offline   Reply With Quote
Old 07-10-2013, 08:11 PM   #13
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

Quote:
Originally Posted by WRX boarder View Post
I've never noticed the AWD light on the WRX.
Not the AWD light. The one pictured right above the AWD light.

Here is a video of a 2012 starting up.

Notice how it has the light that is displayed via toggling the switch (sliding car with OFF below it). There is just the sliding car light right near the coolant temp gauge.

These lights are the same lights as can be seen in the video I linked earlier with the guy explaining how the VDC system works.
redline23 is offline   Reply With Quote
Old 07-11-2013, 09:43 AM   #14
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

What I am talking about, is while I was at a rallyX event, lots of mud, my car would slow and not respond when stepping on the gas. Ultimately, I would come to a stop, or almost a stop, mid corner, and have to shift to first and start over.

The VDC was off. Something was preventing me from keeping the rpm's up, so I couldn't drift through the corner.

It didn't do this on every corner, just the tighter ones. I was as if the car was just bogging down, but something was causing it to.

I had great wheel spin through straight aways, with slight fishtailing. I could go through slaloms fine, and the larger radius corners fine. On the larger radius', I could drift through completely sideways, power stayed up, wheels spun, I was able to maintain speed.

Does that make sense?
Real Fast Travis is offline   Reply With Quote
Old 07-11-2013, 10:41 AM   #15
Dmochowski
Scooby Specialist
 
Member#: 306478
Join Date: Jan 2012
Chapter/Region: South East
Location: chattanooga, TN
Vehicle:
2012 WRX limited
305whp/360tq TSM tuned

Default

The only thing that comes to mind with me is a slow speed tight corner you will have more of a tendency to overpower the inside wheels with an open differential and your car is applying a lot of breaking force to overcome that so maybe it just caused you to bog down? You know as much as I do about the subject so your guess is as good as mine
Dmochowski is offline   Reply With Quote
Old 07-14-2013, 02:22 AM   #16
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

Ok.... Did a rallyX event today, and pulled the only ABS fuse I could find, the one under the hood, a 30 AMP one marked ABS solenoid. That did the trick! The car never bogged down, it would spin all four from launch, do doughnuts with ease, and slid through the turns effortlessly! Yay!

Of course, all the lights were on, on the dash... for ABS, traction control, hill assist, and e-brake. And no cruise control.

Next up, disabling the system without throwing codes, and still having a functioning cruise. But for now, I am just glad I solved this problem. On to the next event!

Is it August yet?
Real Fast Travis is offline   Reply With Quote
Old 07-14-2013, 04:18 PM   #17
WRX boarder
Scooby Newbie
 
Member#: 328399
Join Date: Aug 2012
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
2012 WRX Limited
OBP

Default

Quote:
Originally Posted by Real Fast Travis View Post
Ok.... Did a rallyX event today, and pulled the only ABS fuse I could find, the one under the hood, a 30 AMP one marked ABS solenoid. That did the trick! The car never bogged down, it would spin all four from launch, do doughnuts with ease, and slid through the turns effortlessly! Yay!

Of course, all the lights were on, on the dash... for ABS, traction control, hill assist, and e-brake. And no cruise control.

Next up, disabling the system without throwing codes, and still having a functioning cruise. But for now, I am just glad I solved this problem. On to the next event!

Is it August yet?
ymmv, but remember spinning wheels increase risk for damage to your center diff
WRX boarder is offline   Reply With Quote
Old 07-16-2013, 02:32 PM   #18
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

Quote:
Originally Posted by WRX boarder View Post
ymmv, but remember spinning wheels increase risk for damage to your center diff
In what way?

I know nothing about any of this, so any info is appreciated.

I just don't see how I can run with the system intact.
Real Fast Travis is offline   Reply With Quote
Old 07-23-2013, 08:58 AM   #19
redline23
Scooby Newbie
 
Member#: 285799
Join Date: Jun 2011
Chapter/Region: MWSOC
Location: La Crosse, WI
Vehicle:
2012 WRX 5-Door
WRB

Default

From how I understand it, The center diff is a viscous unit. It works by having a thick fluid between two rotating cylindrical shapes. One of the cylinders is connected to the front wheels, the other to the rear wheels. This gives you the following situations

1) Front and Rear wheels are spinning at same speed. Therefore, the cylinders and fluid are spinning at the same speed. This is normal operation
2) Front wheels are spinning faster than the rears. Therefore, one of the cylinders is spinning faster and the fluid starts heating up. As the fluid heats up, it thickens. As the fluid thickens, it opposes the differential speed of the cylinders. The faster spinning cylinder is slowed down, and the slower spinning cylinders is sped up.

Now I am not clear on how this will cause damage to the center diff, so I will not even pretend to know what I'm talking about.

This post brought to you by lack of caffeine and the word cylinder.
redline23 is offline   Reply With Quote
Old 07-23-2013, 05:19 PM   #20
Real Fast Travis
Scooby Newbie
 
Member#: 361850
Join Date: Jul 2013
Default

Quote:
Originally Posted by redline23 View Post
From how I understand it, The center diff is a viscous unit. It works by having a thick fluid between two rotating cylindrical shapes. One of the cylinders is connected to the front wheels, the other to the rear wheels. This gives you the following situations

1) Front and Rear wheels are spinning at same speed. Therefore, the cylinders and fluid are spinning at the same speed. This is normal operation
2) Front wheels are spinning faster than the rears. Therefore, one of the cylinders is spinning faster and the fluid starts heating up. As the fluid heats up, it thickens. As the fluid thickens, it opposes the differential speed of the cylinders. The faster spinning cylinder is slowed down, and the slower spinning cylinders is sped up.

Now I am not clear on how this will cause damage to the center diff, so I will not even pretend to know what I'm talking about.

This post brought to you by lack of caffeine and the word cylinder.

Thanks... and I am with you on this, curious how damage will occur.
Real Fast Travis is offline   Reply With Quote
Old 07-22-2014, 09:57 PM   #21
cchrisrollins
Scooby Newbie
 
Member#: 357589
Join Date: May 2013
Default

I am far from an expert on this stuff, but I had researched info on the diffs before and I believe the only diff that is open is the front. There is a VLSD (viscous limited slip differential) in the middle and the rear of the 2012. I have a 13 wrx and just did two auto X weekends in a row and was considering pulling the fuse on mine as well. I't is definitely noticeably interfering, even with the TC button "off".
cchrisrollins is offline   Reply With Quote
Old 07-22-2014, 11:41 PM   #22
tuskenraider
Scooby Specialist
 
Member#: 65699
Join Date: Jul 2004
Chapter/Region: MWSOC
Location: S.S. Chicago
Vehicle:
15 WRX
WR Blue

Default

Quote:
Originally Posted by cchrisrollins View Post
There is a VLSD (viscous limited slip differential) in the middle and the rear of the 2012. I have a 13 wrx and just did two auto X weekends in a row and was considering pulling the fuse on mine as well. I't is definitely noticeably interfering, even with the TC button "off".
There hasn't been a rear viscous diff in a WRX since 2007.
tuskenraider is offline   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
Forum Jump


All times are GMT -4. The time now is 04:00 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.