VDC/ABS Guru Needed for Tire Size Question!
04-20-2009, 07:01 PM
#21
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Spike
I drive an 03 Track Model. I track the car with VDC off, and yes, the ABS is fully functional during that time....as you suspected. Pushing the VDC OFF button doesn't affect the ABS system in the least.
My only complaint is the ABS turned itself off, and then apparently reset itself when I restarted the car.
I'm convinced there is a delay in the system, as to when the computer tells the functions to shut down. The new wheels don't have the TPMS sensors installed, and it takes the ECU a good 30 miles before the annoying orange warning light comes on. I think that once I activated the ABS system on the track, the ECU said "Nope. We don't like what we're seeing here" and shut itself down. Not a good safety feature if you ask me.
I'm hoping that getting a 225/45/17 front will fix the ECU's discrepancy. What is your opinion??
I drive an 03 Track Model. I track the car with VDC off, and yes, the ABS is fully functional during that time....as you suspected. Pushing the VDC OFF button doesn't affect the ABS system in the least.
My only complaint is the ABS turned itself off, and then apparently reset itself when I restarted the car.
I'm convinced there is a delay in the system, as to when the computer tells the functions to shut down. The new wheels don't have the TPMS sensors installed, and it takes the ECU a good 30 miles before the annoying orange warning light comes on. I think that once I activated the ABS system on the track, the ECU said "Nope. We don't like what we're seeing here" and shut itself down. Not a good safety feature if you ask me.
I'm hoping that getting a 225/45/17 front will fix the ECU's discrepancy. What is your opinion??
Here is something that’s interesting, but not directly related to your question about ABS failure: I do not install the sensors in my winter wheel/tire setup, and I never see the warning light on my dash as you do (I only have “----“ displaying in the upper LCD instrument cluster when going to the front or rear tire function, but not the orange warning light in the dash console).
What I’m saying is that I doubt that the delay you see with TPMS has anything to do with the ABS failure (If in fact that was your point which I’m not sure that it is).
Truthfully, I am unable to provide a reliable answer for your problem report (ABS failure). I’ve run some renegade 17” wheel/tire setups (mostly for my winter tires) on my 2003 VDC-equipped Z, and I did experience some failure with VDC (and, that happened with undersized tires on the rear), but ABS has always worked no matter what size tires I put on the car.
I’m worthless for help on your problem
. If you do find the answer, please let us know.--Spike
04-20-2009, 09:03 PM
#22
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I have a 2003 Performance model which I assume is identical in its VDC and TPMS setup as your 2003 Track model.
Here is something that’s interesting, but not directly related to your question about ABS failure: I do not install the sensors in my winter wheel/tire setup, and I never see the warning light on my dash as you do (I only have “----“ displaying in the upper LCD instrument cluster when going to the front or rear tire function, but not the orange warning light in the dash console).
What I’m saying is that I doubt that the delay you see with TPMS has anything to do with the ABS failure (If in fact that was your point which I’m not sure that it is).
Truthfully, I am unable to provide a reliable answer for your problem report (ABS failure). I’ve run some renegade 17” wheel/tire setups (mostly for my winter tires) on my 2003 VDC-equipped Z, and I did experience some failure with VDC (and, that happened with undersized tires on the rear), but ABS has always worked no matter what size tires I put on the car.
I’m worthless for help on your problem. If you do find the answer, please let us know.
--Spike
Here is something that’s interesting, but not directly related to your question about ABS failure: I do not install the sensors in my winter wheel/tire setup, and I never see the warning light on my dash as you do (I only have “----“ displaying in the upper LCD instrument cluster when going to the front or rear tire function, but not the orange warning light in the dash console).
What I’m saying is that I doubt that the delay you see with TPMS has anything to do with the ABS failure (If in fact that was your point which I’m not sure that it is).
Truthfully, I am unable to provide a reliable answer for your problem report (ABS failure). I’ve run some renegade 17” wheel/tire setups (mostly for my winter tires) on my 2003 VDC-equipped Z, and I did experience some failure with VDC (and, that happened with undersized tires on the rear), but ABS has always worked no matter what size tires I put on the car.
I’m worthless for help on your problem
. If you do find the answer, please let us know.--Spike
As far as the TPMS goes, I was saying it took the car a long time to analyze, and then decide there were no sensors.
I'm guessing the ABS is doing the same thing, and waiting until I actually use it, and then deciding there's something funky going on. It may just be a coincidence I swapped wheels right before this happened, but I doubt it.
It could be what Dave said, and going into some kind of ICE mode failure. It did indeed reset itself, so who knows. I'll get a pair of smaller front tires, and if it happens again, I'll know there's more to it than a tire size issue. I'll be autocrossing again soon, so I'll know soon enough. Thanks for your help.
04-20-2009, 09:10 PM
#23
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Here's part of the problem with VDC - hence the threads about "fully" disabling it. When you turn it off, it's not really 100% off. You can beat it hard and never have it kick in, but there is some point where you really upset the car and the ICE mode kicks in.
There's a note in the FSM under the system descriptions that states:
The ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when the vehicle is subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the engine is running. In this case, restart the engine on a normal road, and if the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off, there is no problem.
While it sounds like the mode can be triggered by subtle movements, in reality it is triggered by violent movements. I've spun my Z in a couple autocrosses and while VDC was off, it appeared to kick in anyway. I didn't trigger the ICE mode though.
There's a note in the FSM under the system descriptions that states:
The ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when the vehicle is subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the engine is running. In this case, restart the engine on a normal road, and if the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off, there is no problem.
While it sounds like the mode can be triggered by subtle movements, in reality it is triggered by violent movements. I've spun my Z in a couple autocrosses and while VDC was off, it appeared to kick in anyway. I didn't trigger the ICE mode though.
04-20-2009, 10:09 PM
#24
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You will be just fine with your other suggested front tires. My car too has had all the lights come on, it was a weekend i ran non staggered VDC off and had a big spin(autocross ) when it flipped out.
04-21-2009, 12:03 PM
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I flat spotted the fronts on Sunday during my smoke filled slide, so I'll have a lot of fun with them on the rears.
05-21-2009, 10:12 AM
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Running the same size tires minus 1" seemed to work just fine through 18 laps. I was having to upshift a bit sooner with the 17"s, but otherwise there was no more drama. Thanks guys for all the help!
07-06-2009, 03:42 PM
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I'm about to change my wheels and tires. I'm thinking about a higher profile in the rear (i.e. 225/40 front 245/45 rear). Is there any benefit to this setup up or it just for looks. Will an equal height from front to rear be better for handle/MPG? 
Terrasmak,
A lot of people claim that it's a 3% diameter difference vs stock. You're the first that says it's the difference between Front to Rear. Why?
Why do people thing its a 3% thing with stock size, its a 3% thing with front to rear. you could run a 35 in truck tire in the front and a slightly larger (withing 3%) in the rear and VDC willnot care. Same goes if you were to put 13 inch reverse offset daytons on your car. 175/70-13 and some 195/70-13's and your good to go.
Yes a lot of people run square setups without problem (with VDC/TCS off)
Yes a lot of people run square setups without problem (with VDC/TCS off)
Terrasmak,
A lot of people claim that it's a 3% diameter difference vs stock. You're the first that says it's the difference between Front to Rear. Why?
07-06-2009, 03:57 PM
#28
Because that's what we've always been talking about. The front tires must be a smaller OD than the rears. Practically, the difference needs to be about 0.25 to 0.75". Some have also claimed the 3% difference. Both are anecdotal as nothing has ever been published by Nissan to go by.
07-06-2009, 04:12 PM
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Because that's what we've always been talking about. The front tires must be a smaller OD than the rears. Practically, the difference needs to be about 0.25 to 0.75". Some have also claimed the 3% difference. Both are anecdotal as nothing has ever been published by Nissan to go by.
If that's true then it would explain a question I've had for weeks now.
My current tire setup (by prev Z owner) is more than 3% OD vs stock. When I calculated that on 1010tires I was completely surprised yet my ABS, VDC, or other lights weren't on. My car hasn't been indicating that I have a problem. I've wondering why.
Before reading your reply I decided to check my OD between the front and rear tires. It is in fact <3% and that explains why I have a >3% OD vs stock yet my car isn't reading any errors. Profound information.
I'm still considering having a larger profile in the rear vs front. I imagine that handling would be effected ( I would get more oversteer) but I'm ok with that. Would another element suffer such as MPG?
Last edited by KuNoichi; 07-06-2009 at 05:50 PM.
07-06-2009, 04:22 PM
#30
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Because that's what we've always been talking about. The front tires must be a smaller OD than the rears. Practically, the difference needs to be about 0.25 to 0.75". Some have also claimed the 3% difference. Both are anecdotal as nothing has ever been published by Nissan to go by.
The Z begs for customization, but Nissan cannot safely make recommendations past the Nismo "add-on’s." That’s why my350z.com is such a great resource. Members here share their experiences when improving the Z, and readers benefit greatly from this advice.
--Spike
07-06-2009, 04:35 PM
#31
Let me clarify something regarding the 3%. My interpretation is that 3% is the variation in OD from front to rear, not the variation in OD from the OEM tire diameters.
If the max diff is about 0.75" and the typical tire Od is about 25", then that works out to 2.8%.
If the max diff is about 0.75" and the typical tire Od is about 25", then that works out to 2.8%.
07-06-2009, 04:39 PM
#32
Taller tires would probably increase your MPG. For the same revolution of the drivetrain, the larger OD and circumference would make you travel farther. You'd get better mileage from a narrow tire but traction suffers.
07-06-2009, 04:40 PM
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Dave, I think your point is the best made on this thread. In our litigious society, Nissan is pretty much forced to recommend never deviating from the stock wheel/tire setup that comes with the car you purchased. Of course, that’s no fun at all.
The Z begs for customization, but Nissan cannot safely make recommendations past the Nismo "add-on’s." That’s why my350z.com is such a great resource. Members here share their experiences when improving the Z, and readers benefit greatly from this advice.
--Spike
The Z begs for customization, but Nissan cannot safely make recommendations past the Nismo "add-on’s." That’s why my350z.com is such a great resource. Members here share their experiences when improving the Z, and readers benefit greatly from this advice.
--Spike
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