someone posted a thred that said he turned off the VDC and couldn't beleive the power....someone want to give me information on what VDC does and why he went faster? Thanks in advance.

 

Makes sense in a way since turning the VDC off will eliminate any power cut off on hard launches. I personally do feel more power being sent to the wheels when I launch without the VDC.

 

so what exactly does it do???

 

VDC bogs the engine down when the tires break loose and spin.....this robs you of power and makes you launch slower.

 

VDC will cut power to the wheels when it senses wheel slippage/spinning. If you have the VDC on and try to drop the clutch at high RPMs (hard launch) the VDC will immediately cut the power to the wheels and instead of wheel spinning what you'll feel is as if the car is being held from behind (sort of) and will launch it slowly until you reach an adequate speed where the wheels won't spin at which point it will turn itself off and send full throttle power to the wheels.

On the other hand, if you have the VDC off and you drop the clutch, what you get is full spin at max torque. I'm not sure of the exact mechanism involved in cutting the power out via the VDC, but some people claim it's the clutch, while others claim it's just plain electronic function of the ECU.

 

It uses the car's braking system and engine to correct what it sees as irregularities in the car's performance. Using traction control and an engine monitoring system, it detects wheel slippage and provides inputs, either through braking, engine retardation, or a combination of the two, to restore stability in the car's handling.

If you nail the G off the line, the rears are going to spin. The VDC system sees this as an 'irregular function' and retards engine performance or applies braking the the affected wheel(s) which will reduce performance. Disabling VDC allows for a little wheelspin (or a lot, depending on how much you want to dish out) and will get you out of the hole quicker.

Something like that.

 

i appreciate it ya'll.... thats helped alot

 

Yep, it brakes and closes the TB. My understanding is that when you turn off VDC, it's still on, albeit less intrusive. The only way to completely kill VDC will be to pull the VDC fuse under the hood, however, this also kills your ABS.

 

Is that really true that it can't be completely defeat via the switch? If not, I guess pulling the fuse is really driving it hard core since it also disables the ABS

 

I got stopped on a patch of smooth ice one day. Started out driving in Arkansas last november and drove to see some family in Missouri. Roads were perfectly clear all the way up there. But the cul-de-sac that my sister lived in wasn't clear. Had smooth ice all over it. I unknowingly stopped in the middle of it. There was a very slight uphill to it and I couldn't move the car. vdc kept killing the gas as soon as the wheels spun. So I turned it off via the switch and it would then let me give some gas and spin the wheels a little bit (<1000 rpm on the tach), but if I really spun them (~1500 rpm or more) then they would suddenly stop. Engine cut power to the wheels. I think there might be sort of two systems, traction control and vdc. I think the vdc uses the traction control system in doing it's job, as well as brakes. But even if you turn off vdc the traction control remains. It definitely isn't nearly as intrusive as the vdc is though.

 

Ya its two systems.. Your basic traction control. (Cuts power to the wheels as they slip) and the automatic braking system. (Brakes the wheels that slip) When its dry out the VDC is not good if you are driving hard... However when its wet or icey the VDC can keep you from spinning out.

It always irks me when I hit an on-ramp really hard on a nice sunny day and the VDC decides to brake hard on one of the wheels (feels like big brother trying to tone down my driving), but thats what the switch is for, so I shouldn't complain.

I haven't noticed the VDC or traction control when the VDC is off..

 

Yes thats true, turning the switch off does not totally disable the VDC. If you want to completely disable the VDC (although this is sort of a noisy and distracting way of doing so) push the button to turn it off and pull a couple of burn outs or slides. SLIP will remain lit your dash, indicating VDC is completely disabled. Turn the car off and then back on, SLIP will be gone and VDC will be functioning normally.