so im taking access ramps... (the curved ones) at about 55-60 mph and i hear a spinning/rattling metal on metal noise.... my "SLIP" light flashes on my gauge cluster... and i feel vibrations as i accelerate through the turn... i run with VDC on most of the time... do i need to replace my LSD??? i drive a 2003 perf Z with all nismo parts... no oversized wheels... and i have Z rated tires... this is the only problem i've run into... any advice?


TT

 

While you may have Z rated tires, what are the sizes of the fronts and rears? If the stagger is off, then that can cause the problem you are describing. Have you replaced fronts or rears lately, again, mixing new and old tires have caused this for some people.

 

Wait.. these cars are that specific with tires?

What tires should I run when I change mine....?

 

i recently added a new pair of perrelli p-zero neros to the rear.... while the front are about halfway worn... and an update..... today i tested it out on an access curve again... today it was worst... the vibration was more fierce and the car actually started slowing as if i were pumping the brakes... btw im running the recommended set up for the nismo 18 inch rays..... 275/40 18... i dunno i really dont want to have to replace a lsd right now... lol my pockets are tight.... i've done this before with tires on the rear and i didnt have this problem...

 

i have never had problems with perelli p-zero nero m+s till now.... up till today and yesterday they were some of the best tires i've ever purchased.... they're expensive though... a pair of 275/40 18's ran me about $480shipped...

 

It's not the price or quality of the tires, it's the sizes and the slipperyness of them. Old tires are worn down and not the same diameter as orginally. Put some new ones on the other end of the car and you may throw off the stagger (diff of front /rear diam). New tires are "slippery" and loose traction easily and the VDC/TCS will react to that. I assume you have 245's up front and 275's in the rear, correct?

 

You can run just about any tires, what matters is the outside diameter difference between the front and rears. The rears should stay about 0.25 to 0.75 inches taller than the fronts.

If you buy the same size tires as it came with, you shouldn't have problems.

Experience has shown that mixing brands and/or new vs old tires has caused TCS/VDC problems for a few people. It just depends on your specific conditions. I just put new Michelin PS2's on the front of my car and drove it or a long road trip and two track days and never saw a problem once. There are some recent threads in the Wheels, Tires forum from guys who replaced front or rears and starting having issues. They then changed out the other set and the problems went away.

 

From the OP's description, it sounds like your back end is starting to come out a little and VDC is kicking in to keep the car straight. In other words, it sounds like it's working as intended.

If you run with the VDC off you might start drifting a bit.

 

correct 245/40s.... li ke i said i never had that problem on the previous changes.... bu then again the last change was in the summer... so the heat and raod conditions might have played a role... and yes the rear feels a bit "wet" ... i was thinking about burning out a couple times to break them in... lol might be a bad idea though

yeah it "sounds" like its kicking in... but it feels wrong to me... when its kicked in b4 the car just slowed drastically... and i put the tires on about 3 weeks ago... i figured they'd be broken in by then.... what botherd me was that this JUST started happening and i put them on so long ago... of all the time my VDC kicked in and slowed me down the vibrations and agressive "brake pumping" feel has never happened... i'll keep breaking the tires in and see what happens thanks for all the input i learned something....

 

+1

You are just reaching the limits of adhesion, and the VDC kicks in (usually a little too soon for many drivers). I drive with VDC/TCS off about 98% of the time.

 

Same here. The only time I leave it on is when there are bad road conditions where theres a possibility I will lose traction unintentionally. Like in the rain or going on a gravel road.

 

i had my tcs on one time n that happend i was goin about 50 at a turn i tink its my tires tho cuz my check tire sign has turned on ever since it got cold

 

ok makes sense... i'll try driving it with the VDC off today and see how it feels... thanks for the input guys...

TT

 

I think the Moderators have already answered your question, but thought I would just mention that I had nearly the same experience you describe. I also have a VDC-equipped 2003 Performance model so it’s a pretty direct comparison.

I put new rear tires on last spring. I immediately noticed the “greasy/slippery new tire syndrome” upon leaving the tire dealer and driving on the freeway. I believe my experience was exaggerated by the fact I had the OEM Bridgestones (stiff sidewalls) on the front and mounted new Goodyear Eagle F1 GS-D3 (soft sidewalls) on the rear. Anyway I took it easy for a couple of weeks, but still had exactly what you described happen at about 14 days on the new tires. I suppose the best thing would be to turn off VDC when the tires are new and the roadway is dry, and drive hard enough to burn-off that grease.

The “spinning/rattling metal on metal noise” noise you heard was your ABS engaging. VDC detected a slight misalignment of the car’s direction to the direction front wheel were pointed (a slight slip off the rear end), and tapped the rear brake(s).

I know that some people here advocate keeping VDC off, but I almost always have VDC on since statistics from the insurance industry show that stability control devices make cars safer.

--Spike

 

^^ i rarely drive with the vdc off.... when my last set of rears were broken in... it literally felt like i was carving into the street best handing car i've ever driven... im sure there are better suspension set-ups but i have the nismo s-tune suspension with the front and rear sways.... love it to death... thats why i was kinda flipping out when this started happening... i went from feeling like i was glued to the pavement to feeling like i was driving a murano... its all good though again thanks for the input... you guys saved me a trip for diagnostics... damn i love this forum...

 

Well just so you know...

the VDC works a little different from TCS.


The VDC just applies brake to one wheel (not sure whether it cuts fuel)... whereas the TCS cuts fuel and applies brakes to 2 or 4 wheels...

 

That’s good point that I think many people don’t understand fully.

TCS only cuts power and never applies braking, and that “power-cut” only happens when TCS detects a significant difference between rotation speed of the front and rear wheels. More simply stated, TCS kills power to the rear wheels when it “thinks” you are in trouble. In this case you see the SLIP light. Another part of this is simply saving your expensive performance tires when they begin slipping too fast and wasting “rubber.”

VDC is a full-featured stability control device that incorporates both TCS and also braking at individual corners of the car to maintain the car’s direction in relation to the direction the front wheels are pointing. It’s a very sophisticated device that works quite well (I’ve experience this firsthand). Since VDC incorporates TCS, it does what TCS-only-equipped-cars do when the rear wheels begin rotating too fast in relation to the front wheels; it cuts the power.

But, VDC will do even more to keep you safe. If the rear of your car moves outside the direction your front wheels are pointing, VDC goes to work (almost instantly) by applying the car’s brakes at any individual corner (usually at the rear) to straighten the car to the direction the front wheels are pointing. The “grinding-metallic” noise people report is simply ABS activation. If your car begins to rotate, I believe VDC first applies braking to the inside rear wheel; and if that isn’t enough, VDC brakes both rear wheels (to drag the rear end and straighten the car’s direction). You definitely hear and feel ABS when VDC applies your brakes. VDC also activates TCS to slow the car.

One thing that VDC owners should do is allow VDC to do its work instead of counter-steering. Counter-steering can only compound the problem. I’m sure that accomplished rear-wheel drivers may not want to surrender direct control to an electronic device, but insurance statistics show you’re better off allowing the electronic stability control device to get you out of trouble.

Certainly when driving hard, drifting, or doing other “out of the normal driving,” it may be prudent to turn VDC off and use your driving skills to handle situations VDC was never designed for. But, VDC makes your car safer during normal daily driving, especially when the roadway is wet or slippery (and slippery can happen when it looks dry but the roadway has a slippery coating such as diesel exhaust after a long dry period with a little bit of moisture). 99.99% of the people who report problems with VDC have the wrong sized tires mounted on their cars. They never want to admit this, but when you press them it is always the same story.

Disclaimer: These comments are based only in my personal experience. I have no real statistics to back what I’ve said. If someone wants to comment, argue, or add additional information, that would be great.

--Spike