Hey everyone. I just put a different set of wheels on my car yesterday (just a set of 06+ stockers) and the front tires are the stock 225/45/18 and the rears are a brand new set of continental extreme contact dws 245/45/18. Everything was just installed yesterday, and now im having a problem. When going through a corner, the VDC automatically kicks in and causes the car to jerk really bad. It doesn't feel safe at all and I'm wondering what you guys think. I honestly don't think the tires/wheels are the cause, they are just the only thing that has been changed since I last drove the car in April. Here's a quick video.

http://smg.photobucket.com/albums/v7...t=IMG_0224.mp4

Let me know

 

From the symptoms, I'd say you have the wrong size tires on the car. You state what appears to be the correct size though.

First, I'd double check the sizes. I'm guessing the rears are really 245/40/18.

 

pretty sure this isn't a wheel and tire issue. I was just stating the only thing to be changed since last driving it
EDIT: Tires are 245/45/18 I just went and checked

 

Actual tire height may be the issue with two different tire brands. Do you still have your old set of wheels? Swap back and see if the problem is still there.

 

Tire size is good. This is not the problem.

NOTE: You mention OEM wheels. Make sure the correct wheels are on the correct axles.

 

The other possibility would be a damaged wheel speed sensor - but that would cause VDC to kick in all the time, not just in turns.

New tires can be slick as a result of the release agent coating them, that could truly cause a slight slipage but you should be able to feel it.

BTW - your video is useless.

 

Could be the front tires arn't as good as the rears and they are actually losing grip. Thats whay mine did when i first swapped out my worn rear tires to INVO's.

 

I just installed Continental Extreme Contact DWS tires on my car (245/40-18” front and 245/45-18” rear) on my VDC-equipped 350z, so I have some experience with the tire you are using. Here is what I think is going on in your case (where you are experiencing unwanted VDC-activation).

You said: “ […] and the front tires are the stock 225/45/18 and the rears are a brand new set of continental extreme contact dws 245/45/18.”

I’m assuming you have the stock Bridgestone summer-performance tires on the front. If my assumption is correct, here is what I believe is the problem:

• Your front tires are summer-performance tires with better grip and stiffer sidewalls than your rear all-season rear tires.
  
• When entering a turn at speed, the rears flex more, and will slip (maybe just a little that is imperceptible to you the driver) just enough to trigger VDC.
  
• Your new rear tires are still “greasy” (as DavesZ#3 mentions) and thus slip more until they are “scrubbed-in” which could take a few hours of driving.

I really like my new Continental Extreme Contact DWS tires; however, they do not grip nearly as well as summer-performance tires. You can prove this to yourself by accelerating hard from a stop. Notice that you get a slight “chirp” from the DWS all-season tires that you never noticed when you had summer-performance tires on the rear.

I have mixed summer-performance tires with all-season tires front-to-rear), and the result is always unsatisfactory (i.e., poor handling, excessive VDC/TCS activation, etc.).

If you can justify the cost, I would mount a pair of Continental Extreme Contact DWS tires (225/45-18” or 245/40-18”) on the front to match your DWS rear tires. Doing that will eliminate the VDC problem you are reporting. I fully understand that it isn’t very palatable to throw out perfectly good tires, but that is your fix.

--Spike
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EDIT: Just read msg. from terrasmak. He makes a good point. Excessive wear on the front tires could certainly be the culprit. In this case, it would be almost the opposite of what I describe above. The fronts would be “pushed out of line” to the rears, and that could certainly result in VDC activation. Check your front tires for excessive wear. If that is the case, buying new DWS’s for the front is an easy decision, and your problem is fixed.

 

Front tires have plenty of tread left on them. I would think it would be the tires wayyy more if it were in a hard corner that it did this, but it's not, it's 50mph through a wide corner

 

Are you letting off the gas as you start to turn in? That deceleration along with the direction change can cause VDC to kick in.

 

Yeah, if I let off the accelerator and go through a corner it does it. That's the 'best' way I know to make the problem show up and be most evident. There are a long of corners I just let off the accelerator on, and this is still a brand new problem. I had a friend in the car last night and it was a lot worse going into a corner, but too dark to videotape anything. Should I just take it to Nissa/a shop, take them out in the car and show it to them? I'm usually working on my own car, but this has me baffled.

 

Try holding a constant speed or accelerate through the corner and see if it still happens. I noticed a similar problem a few weeks back. It was happening on the same Interstate entrance ramp I've used for years. After it did it two or three times, I started paying attention and realized when I slowed for traffic in front of me was when it occurred. Basically, the G-sensor detects that you've let off the gas or applied the brake while entering a turn. That shifts weight to the front wheels so to prevent the rear from potentially breaking loose on you, VDC kicks in and applies the appropriate brake(s) for you.

I wouldn't bother taking to the dealer to get it checked - it's working as designed.

 

Yeah I'll give it a try. I can totally understand where you're coming from, but I'm not braking when it happens, just letting off the gas

 

Happened to me one time, I let some air out of the fronts, issue went away.

This was after switching to larger fronts too.

 

It has the same effect as tapping the brake, weight transfers to the front making the rear lighter. That's why the worse thing you can do if the tail starts to get loose in a turn is to hit the brakes - that almost guarantees that the tail end will whip around and pass the front end.

Keep in mind that a lot of this problem is probably also brought on by the new rear tires. They are slippery and they are different than the fronts (make and model). They have different characteristics which just work into the whole equation of the car's dynamics. Once you've driven on them for a while the issue may go away, even when slowing into a curve.

 

I think Dave provides the correct answer.

I had a very similar experience (a few years ago) when I installed new rear summer-performance tires. My fronts were fairly new OEM summer-performance tires (Nissan provided me with new fronts because of the “feathering problem”). The greasy new rears were slipping imperceptively, but enough to cause VDC-activation. This happened in the exact instance you describe (a long sweeping turn at moderate speed). After a few hours of driving, the rears became “scrubbed-in,” and the problem went away.

I experienced the same problem on a road trip when I lost a rear tire and had to buy new rears at a station in a small town. The small shop only had 245/45-18” tires in all-season, so I ended up with summer-performance tires on the front and all-season tires on the rear. The result was awful (poor handling, unexpected VDC-activation, etc.). And again, the problem was mostly evident on long sweeping turns while slowing the car. And, that didn’t improve with driving time (and why I mention that it is not a good idea to mix summer-performance tires with all-season tires).

I’m not having any VDC issues with my Continental Extreme Contact DWS tire/setup (the tire you mention), but I’m running the DWS’s on all corners (245/40-18” front with 245/45-18” rear).

Hope this info is helpful,

--Spike

 

I am also baffled. Looks like you are maintaining RPM through the curve. This should present no problem for VDC.

As Spike100 mentioned new tires are slippery. Give them 100 miles.

 

David, I also find this problem perplexing since dustin15brown is running the correctly sized tires on his VDC-equipped car. I can only think the problem happens because there is a disparity of dry road grip between the front and rear tires.

A question for dustin15brown: What happens if you apply power at the time you get VDC-interference?

Applying a light amount of acceleration on a dry roadway would load the rear slightly, and possibly remove the VDC-activation. If you have not tried doing this, please run this experiment and report back. That test will help us learn.

--Spike

 

I'll try it all today. And the tires now have 200 miles on them so it shouldn't be they are slippery (My hometown is 100 miles from my college, so my initial drive back up here should have eliminated the slippery issue.

 

What happens if you apply power at the time you get VDC-interference?
-I tried this today and I applied acceleration after it started to jerk, and it kept jerking (not as hard) and did let me accelerate. That was just an interstate test, so I'm going to find some twisties hopefully tonight.
Question: If VDC is kicking in, could there be a potential that my rear end is trying to lock up? If so, should i find a corner that it kicks in, and before the corner, turn off my vdc and see what happens? Or does that seem like a recipe for disaster?