Nissan Titan Forum banner

Will Installing Different Size Tires/Rims Make VDC Not Work?

11K views 57 replies 8 participants last post by  the_head 
#1 ·
First of all, see the thread below on TT.

http://www.titantalk.com/forums/showthread.php?p=255900&posted=1#post255900

The above thread got out of hand real quick and I'm afraid it may have been my fault. :oops: It just stinks of misinformation to me. Nonetheless, the question for all the tech gurus (that means you JetTech, and others) is:

Will installing even slightly different size rims and tires make VDC not work properly??? Apparently a Nissan VP says "Yes"? What gives? Does this mean our ABS and ABLS are not there for us in full effect, with aftermarket wheels and tires, either since VDC utilizes these features as well???
 
#2 ·
Hi TH, I read the post over on TT and to be honest I can't see why different sized tires would have any effect on the VDC function. There is one circumstance I can think of that would wreak total havok on the system and that's installing different sizes front and rear. Now that would confuse the heck out of it, but I see no reason it would get confused by different sized (all 4) tires. If you look at the inputs of what VDC is looking at, it could care less if your running 13's or 24's...

Comparisons between rotational speeds of all 4 tires, along with ABLS inputs (slip), yaw sensor, steering wheel angle, and brake assist all play into the overall operation of VDC. I feel that those who turn it off, during their normal commute, are asking for trouble if they get between a rock and a hard place. It's truly a wonderful feature and IMHO, I think it's the best option out there.
 
#3 ·
The answer is "no, it will not matter" if you change all 4 tires. The answer is "yes, it will matter" if you go different front and rear.

I run shorter tires on the 17" off-road wheels in the rear at the track when dragracing and still have the stock 18" LE wheels and tires up front. If I leave the VDC on, it will activate the 'slip' light at about 20-25mph on the speedo. The VDC thinks the rears are spinning since they are rotating more revolutions than the fronts. This isn't a problem during a run because I turn off the VDC anyway (the traction control will absolutely kill a run if it activates).

The other thing to consider is that right now you can't correct the speedo for different tire sizes. The speedo calibrators you see all over the place will not work on our trucks. There is no "wire" to tap into since it's part of the CAN system.
 
#4 ·
I agree, it should have no affect on the VDC by changing to different wheels and tires as long as front and rear are the same. I would say that the "VP" just has to say things to cover his a$$ is all. If that were the case than you wouldn't be able to replace the tires when they wear out cuz different makes of tires are all slightly different diameters, for that fact the OEM ties will change diameter as they wear out. :) I call BS.
 
#5 ·
I thought so! And it was a good point that not all manufacturers tires are the same diameter even though they are the same size! I have seen as much as 1/2 an inch difference from one brand to another (at least in their specs). It just insenses me when corporate big wigs put out misinformation in a feeble attempt to limit liability and warranty claims.

Yaw Sensors, Steering Wheel Angle (Sensor?), Brake Assist??? What are these exactly JetTech? Thanks for your (and everyones) insight so far.
 
#6 ·
the_head said:
The answer is "no, it will not matter" if you change all 4 tires. The answer is "yes, it will matter" if you go different front and rear.

I run shorter tires on the 17" off-road wheels in the rear at the track when dragracing and still have the stock 18" LE wheels and tires up front. If I leave the VDC on, it will activate the 'slip' light at about 20-25mph on the speedo. The VDC thinks the rears are spinning since they are rotating more revolutions than the fronts. This isn't a problem during a run because I turn off the VDC anyway (the traction control will absolutely kill a run if it activates).

The other thing to consider is that right now you can't correct the speedo for different tire sizes. The speedo calibrators you see all over the place will not work on our trucks. There is no "wire" to tap into since it's part of the CAN system.
So Head, if I am understanding you right, when you turn off the VDC you can light up your tires and make a 1/4 mile pass without the ABLS kicking in? So the VDC switch will also turn off the ABLS?
 
#7 ·
TitanHauler said:
the_head said:
The answer is "no, it will not matter" if you change all 4 tires. The answer is "yes, it will matter" if you go different front and rear.

I run shorter tires on the 17" off-road wheels in the rear at the track when dragracing and still have the stock 18" LE wheels and tires up front. If I leave the VDC on, it will activate the 'slip' light at about 20-25mph on the speedo. The VDC thinks the rears are spinning since they are rotating more revolutions than the fronts. This isn't a problem during a run because I turn off the VDC anyway (the traction control will absolutely kill a run if it activates).

The other thing to consider is that right now you can't correct the speedo for different tire sizes. The speedo calibrators you see all over the place will not work on our trucks. There is no "wire" to tap into since it's part of the CAN system.
So Head, if I am understanding you right, when you turn off the VDC you can light up your tires and make a 1/4 mile pass without the ABLS kicking in? So the VDC switch will also turn off the ABLS?
When you shut off VDC it will not shut off ABLS. It shuts down all the inputs to VDC along with the throttle by wire function so you don't have to worry about the throttle cutting back on you. ABLS remains active...
 
#8 ·
TitanHauler said:
I thought so! And it was a good point that not all manufacturers tires are the same diameter even though they are the same size! I have seen as much as 1/2 an inch difference from one brand to another (at least in their specs). It just insenses me when corporate big wigs put out misinformation in a feeble attempt to limit liability and warranty claims.

Yaw Sensors, Steering Wheel Angle (Sensor?), Brake Assist??? What are these exactly JetTech? Thanks for your (and everyones) insight so far.
Hi TH, these are all inputs that VDC is looking at to help compensate for an undesireable event. It looks at these inputs and then calculates how to straighten you back out by regulating the throttle plate and brakes at each wheel.
 
#9 ·
JetTech said:
TitanHauler said:
the_head said:
The answer is "no, it will not matter" if you change all 4 tires. The answer is "yes, it will matter" if you go different front and rear.

I run shorter tires on the 17" off-road wheels in the rear at the track when dragracing and still have the stock 18" LE wheels and tires up front. If I leave the VDC on, it will activate the 'slip' light at about 20-25mph on the speedo. The VDC thinks the rears are spinning since they are rotating more revolutions than the fronts. This isn't a problem during a run because I turn off the VDC anyway (the traction control will absolutely kill a run if it activates).

The other thing to consider is that right now you can't correct the speedo for different tire sizes. The speedo calibrators you see all over the place will not work on our trucks. There is no "wire" to tap into since it's part of the CAN system.
So Head, if I am understanding you right, when you turn off the VDC you can light up your tires and make a 1/4 mile pass without the ABLS kicking in? So the VDC switch will also turn off the ABLS?
When you shut off VDC it will not shut off ABLS. It shuts down all the inputs to VDC along with the throttle by wire function so you don't have to worry about the throttle cutting back on you. ABLS remains active...
So then how did M4ck smoke his tires in that video? No ABLS on the XE's???
 
#10 ·
Its just a gift from the Burnout Gods. LOL
 
#12 ·
Ok, I don't want to start a war but JetTech is saying that turning VDC OFF doesn't disable ABLS and The Head is saying it does? Can you both explain the source(s) of your conclusions? Thanks.
 
#13 ·
m4ck said:
Its just a gift from the Burnout Gods. LOL
You lucky son of a motherless goat! Why do the Burnout Gods love you so much? No fair! :) Is there a chant or some sort of sacrifice I could offer up to them so that they will bless my Titan with loose tires? LOL
 
#14 ·
I could not do burnouts when I got it. After exhaust and intake I do now.
Whow knows I'm not gonna preach these things. It may just be broken in now.
I really dont know.
M4ck
 
#15 ·
On second thought I'm thinking it may have something to do with my striking good looks.
LOL
m4ck
 
#16 ·
m4ck said:
On second thought I'm thinking it may have something to do with my striking good looks.
LOL
m4ck
If the ability to do burnouts is related to the looks of the driver I'm SOL. :) Hmmm . . . Maybe I'll have my wife try for a smokey burnout! "Oh Honey" . . . LOL
 
#17 ·
TitanHauler said:
Ok, I don't want to start a war but JetTech is saying that turning VDC OFF doesn't disable ABLS and The Head is saying it does? Can you both explain the source(s) of your conclusions? Thanks.
No worries about any war TH, VDC will NOT turn off the ABLS. The_head can pm me for more information if he's confused or unsure.
 
#19 ·
JetTech said:
No worries about any war TH, VDC will NOT turn off the ABLS. The_head can pm me for more information if he's confused or unsure.
Then mine must be broken.

After making over 120 dragstrip runs and doing burnouts for every single one, when I hit the VDC off button and the light on the dash comes on to say that it is off, the ABLS does not function. If I forget to turn off the VDC (which has happened on a few occassions) then the ABLS will function and I cannot do a burnout.

No confusion and no mistaking here - either mine is wired differently or something else because I'm about 120 times for 120 times on the ABLS not functioning when the VDC is off on my truck.
 
#20 ·
I see there is some confusion head concerning exactly what VDC and ABLS do. Here's a little test for you......either in the rain, or on dry pavement, turn off your VDC, shove the throttle to the floor with no brakes. For a split second your right rear tire will start to spin, then the ABLS system grabs that brake and gets the other one spinning too. That's ABLS in action and there is no way, other then to disconnect the rear wheel sensors (of which is kind of cool) to turn it off.

Now I believe what your referring to head is the ability to overcome the throttle reduction that VDC is famous for. With the switch in, and a spinning wheel detected, the VDC will chop the throttle IF.........it has rotational input from all 4 wheels to compare. You can still powerbrake with the VDC switch in as long as your front tires don't move.

If your system is not working like I just described then you do have a problem with it....
 
#22 ·
I'm gonna just throw in what mine does too. :) I have a 4x4 without VDC. What I have found is that when you try to power brake the ABLS light kicks on and it feels like the truck bogs down for a couple second, then both wheels start to spin , the ABLS light goes off and my tires turn into smoke. I think mine is doing what it should be, it stops the one spinning wheel and gets them both going, then when they both are spinning the ABLS has done it's job. Head, it defenitly sounds like your ABLS is not working properly, if at all. But like Jet said, the ABLS is not a function that con be over ridin. You have to vision it as a limited slip diff and nothing more. You can't turn off a standard LSD can you? This is the same concept, just done with the brakes. It has no affect on power delivery of the truck. That being said, if when you power brake your truck it immediatly smokes both tires, then the ABLS won't even step in and do it's job as it isn't necessary, therefor seeming like it was turned off. :)
 
#23 ·
the_head said:
Mine does not work that way.
It would surprise me if your truck has a problem head, perhaps the system is working properly and you're just not aware of what it's really doing behind the scenes. If you would like, pm me your phone number and I'll call you later on this afternoon and try to explain it to you. Sometimes trying to explain things on the net is almost impossible.
 
#24 ·
Well I know what you all are saying, mine just does not do it that way. Really. I have the "one wheel peel" in the burnout box, the second wheel does not start spinning.

Save the phone calls (and long distance) for now. I've raced a lot of vehicles through the years and rebuilt several different posi units myself. I know what you're trying to tell me. But I'm also trying to tell you that mine does not work that way. And I think I have more test data on that than anyone.

If I leave the VDC on, the ABLS works exactly as you describe.

And I'm not saying this old dog can't learn new tricks but I do know what my truck is doing. And everything corresponds with people who have been outside the truck watching me in the burnout box. I hope I'm not coming across as a know-it-all (because I don't) since that is not my intention.
 
#25 ·
Another quick thing: the light that comes on in the dash, the "slip" light. It only comes on in my truck when the VDC is on. When I disengage it, the light never comes on no matter how much I burn the ONE spinning tire.

When I run shorter tires at the track, I could not make a pass on the track with the VDC on. The "slip" light comes on and the truck applies the brakes at about 20mph. I have even tried to drive "through" that but all you can feel are the brakes trying to stop or slow the wheels. I have to run with the VDC off or the ABLS will apply the brakes. I have about 50 runs to back that up.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top