VDC on a g35x, is it with or against the AWD system

[kmckis1029]

Dose VCD function differently on the g35x? i would think so. especially when its off since we have AWD.

Ok i think my question is best worded as which system has the control, or priority, the VCD or the AWD?

if my back tires loose traction with VDC On, which is done first: shifting torque to the front wheels with the AWD system, or brakes/engine power reduction with VDC?

I would assume with VDC Off the AWD system has the most control, with VDC as fail safe.

[kmckis1029]

in my experience so far it seems like the VDC has the most control as the RPMS will drop/pause and you feel the brakes/engine reduction kick in and release once wheel spin is stopped.

with VDC off i have only managed to spin my front tires under heavy acceleration. VDC fail safe will kick in when the back tires try to spin, and apply brakes only as the rpms dont pause/drop.

[zozoka1212]

They work together. I think it is really hard to tell which works first. Both of them are really fast. The Attessa is using your abs sensors and bunch others. It is getting signals 100 times a second from each sensor. So it is damn fast. The VDC if you turn it off, it is not off 100%.

The attesa actually works almost like the VLSD. Think attesa as an advanced VLSD.

zozo

[kmckis1029]

yeah that makes sense why the g35x dosent have a VLSD... wait dose it have on on the front axle?

i personally think the VDC should be second to the AWD system... like with in some time limit or wheel spin percent, if the AWD system doesnt correct wheel spin the VDC should then help.

But if they got them working together, thats good too, but VDC seems to be the Boss of the two.

i'm glad there is a "VDC off" button.

[Sentientbydesign]

The VDC if you turn it off, it is not off 100%.

Where is this information coming from? I've heard it a few times and I don't understand it. When I turn VDC off, it's off. No braking, no throttle interferance.

And I doubt that throwing my car sideways (drifting) isn't enough to make the VDC kick in if it really does when turned off.

[kmckis1029]

when the "vdc off" button is pressed it is put in fail safe mode.. i read this in the owners manual... instead of reducing engine power and/or adding brakes, it just add the brakes only.

i have had the "slip" indicator blink with the "vdc off" button on during a hard left turn from stand still.

[Sentientbydesign]

This is interesting. During my drift event, I had no issues with the VDC kicking it.

There was one run in which the SLIP blinked and stayed on, but after the car was restarted, I encountered no more interference.

Maybe Steve can chime in with some insight on this.

[kmckis1029]

its got to be different on the g35x... as i have NEVER spinned by rears yet... just front.

[zozoka1212]

Where is this information coming from? I've heard it a few times and I don't understand it.

I reread my explanation and it was not clear. Because Attessa using some sennsor as the VDC when you turn the VDC off it the AWD still getting the info from those sensors and the AWD kicks in.

Some Attesa using the leteral sensors wheel rotation sensors,as well as the longitudinal sensors, abs sensors to monitor and adjust the system. I would love to have somebody who can take the ECU and change a few things with Attesa. It would be an awesome car. Right now Infiniti put it for safety first. It should have few different maps and a switch to have sport mode or winter driving,etc. It has a lot more potential then we use it.

I drove so many times in the snow and ice. If you turn the VDC off or not but switch to manual and drive it at 3k and above it is a monster. It goes thru on any slippery stuff like nothing.

I should upload some videos I made. The car is capable to do 0-60 on snow/ice/slush mix in 6 second.

yeah that makes sense why the g35x dosent have a VLSD... wait dose it have on on the front axle? QUOTE]

Some calls the type of system we have as a muti clutch awd system. It works as a vlsd but faster reaction times.

zozo

[kmckis1029]

yes manual mode on the g35x is great! When you in low gears there is basicly no slippage (just front tires sometimes) and the power goes to the ground with vdc on or off.

But of course with vdc off the cars awd shines though... that was why i made this topic... it just seems like the VDC on the g35x works against the AWD system... even though i know the infiniti engineers had to alter the vdc for the g35x.

been looking for more info but a havent found much detail on how the vdc and awd interact yet.

[Sentientbydesign]

I think you hit on something there. If you're driven a RWD G, you'll know that the VDC works against the vehicle too.

In your case, I think it's just more pronounced due to the additional drive wheels.

I'm surprised that the grounding didn't lessen the intrusiveness of the VDC. I'm driving without a kit right now (testing a couple of intake mods) and my VDC feels more annoying than before

Being able to modify the VDC parameters would be very fun lol.

[Sentientbydesign]

Ask and you shall receive!!!

http://www.whiteline.com.au/do...M.pdf

[zozoka1212]

Against-with All relative. Against if you try to push it to the limit. I'd like to have both.

That is a good finding. Do you know anybody who tried it?

Also not sure how it would work with the X.

zozo

[kmckis1029]

the groundint kit has helped alot! the vdc now kicks in and goes away quickly... it used to bog the car down for like 3 sec... more like 1 sec now

[kmckis1029]

Ask and you shall receive!!!

http://www.whiteline.com.au/do...M.pdf

interesting but i would assume the g35x would need some different programing than the 350z.

But infiniti/nissan would be dumb to not make their VDC software modular and configurable... so all they would have to do is input different specs and attributes of each car... but all cars run the same base vdc software/hardware.

[SteveTheTech]

The transmission of torque and the fuel and throttle cut are almost instantaneously. The reaction time of the CAN systems is all done in thousandths of a second.

Now for shutting off the VDC and dogging your X, that's really not a great idea. The transfer case is electronically controlled and needs the input of the ABS system and wheel speed sensors to function correctly. Modifying the vdc output on some cars may not have a dramatic effect on component life but doing this will most certainly damage something.

The G35X is not a race car and is not designed as such. You are free to do as you wish and I am not scolding you for what you do with your car. We have X loaners and I have taken them through the my area the thing moves and I have only had the VDC activate when it's actually slipping. The car does have enough power to break loose with relative ease, but it is designed to maintain traction in all conditions.

As for the product Nate posted I would not advise getting that, it's from a company in Australia and their VDC mapping may and is more than likely different. It will probably be more headaches than it is worth.

[kmckis1029]

i have no plans to change the system.. i was just curious of how the AWD works with the VDC in the G35x...

So with "VDC off" the AWD stystem cant read the abs sensors? So the AWD system is crippled? you slightly confused me.

And YES the G35x will move with vdc Off or On! it puts all the power to the road while other cars tires are squeeling.

[SteveTheTech]

If you are interested on learning about the operation of the ATESSA system check out the TF section of the ESM. This will show you the basic operation of the system and what it uses for input signals this may help you out.

[kmckis1029]

thanks for the info... this doesnt even mention VDC when it describes the awd system... i can see how the VDC would help the AWD system from over heating in snow mode ...

[SteveTheTech]

ABS Function 1. During ABS operation, brake pedal lightly vibrates and a mechanical sound may be heard. This is normal.

2. When starting engine, or just after starting vehicle, brake pedal may vibrate or motor operating sounds may be heard from engine room. This is a normal status of operation check.

3. Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or snow-covered (fresh, deep snow) roads.

4. EBD is integrated in VDC/TCS/ABS system.

TCS Function

1. VDC/TCS/ABS control unit detects a spin at drive wheels by comparing wheel speed signals from all 4 wheels. At this time, output from control unit controls brake fluid pressure to both LH and RH rear wheels while cutting fuel to engine and closing throttle valve to reduce engine torque .Furthermore, throttle position is continuously controlled to insure appropriate engine torque at all times.

2. Depending on road circumstances, driver may have a sluggish feel. This is normal, because optimum traction has highest priority under TCS operation.

3. When vehicle is passing through a road where surface friction coefficient varies, downshifting or depressing accelerator pedal fully may activate TCS temporarily.

4. During TCS operation, it informs driver of system operation by illuminating SLIP indicator lamp. VDC Function

VTC Function

1. In addition to TCS/ABS function, VDC detects driver's steering operation amount and brake pedal travel from steering angle sensor and pressure sensor. Using information from yaw rate/side G sensor and wheel sensor, VDC judges driving condition (conditions of under steer and over steer) to improve stability by controlling brake application to 4 wheels and engine output.

2. SLIP indicator lamp flashes to inform driver of VDC operation.

3. During VDC operation, body and brake pedal lightly vibrate and mechanical sounds may be heard. This is normal.

4. If vehicle is rotated on turn table, or rolled and rocked on ship, ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp may turn on. In this case, start engine on normal road again. If ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off after restart, it is normal.

5. When driving in steep slope such as bank, ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp may turn on. In this case, start engine on normal road again. If ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off after restart, it is normal.



This is about the most you will find in the way of explanation in the book.

[kmckis1029]

Ohhhhh ok the awd is an input to the vdc system! now it makes sense... VDC is Top Dog as everything comes through it. That means when its off each system is independant and doesnt have its Captain VDC...

to infiniti with the design of VDC! (the car is still more fun with it off) VDC gives me great peace of mind when im driving with it on in the GA rain.