hey guys, i wanna get a new wheel and tires for my Z but I heard that larger wheel or wider tires will confuse the VDC. Is that for real? I got an 04 touring currently running 18" stock size with yokohama AVS.

Thanks for any help

 

Who cares VDC is lame anyways.. Just Keep it turned off.. But anyhow i got 19inch rims 8.5 front and 9.5 rear and i dont notice any problems with my vdc

 

as long as the rear tire height is atleast the same or a little taller you will be fine...

 

you mean 45?...I think the stock size is 245-45-18....

 

yeah...i know....but i still wants it on just incase. Anyway, what size tire u running?

 

My tires are 19" 245/35front and 275/35rear.. like i said no problem with VDC

 

Source please? Thanks.

 

Keep the same ratio of diameters front and rear and you'll be fine.

 

VDC doesn't like the rear tire to be taller than the front, and to be safe i would recomend a tire that is slightly taller in the rear...

EX : 285/35/19 = ~26.7" tall
255/35/19 = ~26.0" tall

That is a good combination for the front and rear...

Use this calculator to figure out the height of the tires you want to run.
http://www.sccoa.com/faq/tirecalc.html

 

won't changing tire diameter also affect your spedo and odometer, not to mention the computer (like mileage, trip timer, etc). Sounds like a whole lot of bother for appearances sake, but then again, if it's not your daily driver and just for show, then do whatever because it really doesn't matter.

 

bump n

 

how u calculate the ratio? I just wanna keep the 18" diameter but goes with wider wheels and tires. How wide can you go w/o confusing the VDC? How do you calculathe the width of the rims?

 

You can use the link posted higher in the thread to figure out the total tires diameter of your OEM tires.

Divide the front diameter by the rear and you get the ratio you need to keep. The rear should be about 3% bigger than the front.

 

Thats what I figured.

 

I like this calculator better http://www.discounttire.com/dtcs/infoTireMath.dos
(hey, they are even a sponsor)

What I do is put the front tire in the "What size is being run now?" and the rear tire in the "What size would you like to run?".

Your front/rear sets should always read a higher "You're going approximately" speed, for example the stock 18s read:
If your speedometer reads: 65 You're going approximately: 66.78

Also, if you care about the speedo readings, 779.61 revs per mile seem to be what it is calibrated to.

Chris

 

^ wow!

 

I believe VDC works by calculating the revs between the Front tire and rear tire. So like Kolia said if you generally keep the profile of the wheel the same front to back in a staggered fitment you wont have a problem. In stock form the front is nearly 1" shorter diameter than the rear. I've kept my aspect ratio the same and have had no problems 255/35/19fr and 285/35/19rear.

 

What would be the offsets for this setup? Does it depend also on the wheel (Rim) purchased?

And would it be the same for coupe or roadster?

 

I might just put 255 in the rear...

 

i have similar problems but its my tire pressure sensor that goes off pretty much everytime i drive on the highway. anything i can do to fix it?