terrasmak

iTrader: (8)

From a performance aspect the Z really needs a 245 or larger front tire. Both the 245/40 255/40 and 245/40 245/45 combo's are ideal for best performance with stock wheels

HomeRoy

did nissan go with the 225 front 245 rear to keep things understeery and safe? i was looking at tire prices with 615's and 245/40/18 and 255/40/18 seem like the only reasonably priced combo for me. im just worried it will throw off the balance. then again 255 is alot of tire

terrasmak

iTrader: (8)

That combo works great and with those tires , its a great trackday tire setup.

guitman32

iTrader: (15)

Going with this setup will alter the balance of the car. Make no mistake about it.

I ran this exact setup for a long while, and it took some time to get used to. Once I learned the car's limits with the new sizes, everything was fine and my autoX times jumped noticeably.

HomeRoy

did the new sizes screw up the traction control? what are you running now? im worried about how the 615's dont like to get hot and track days will do that easily

Z1 Performance

iTrader: (564)

615's are not anywhere close to a "track" tire in any sort of skilled run group. If you're a novice, just learning how to feel things out, they will work fine - you won't be permitted to push your car to the point where that tire will be a limiting factor. Focus more on your techniques and following the lines, braking points, etc

terrasmak

iTrader: (8)

615's like heat , and work well for track days, just like any other tire when you get them to hot (overdriving) they get greasy. When greasy they start a nice smooth predictable slide, something some other tires don't do. If you drive them at 100% or lower they are fine, but when you go over, they only require a corner or two to cool down before you start back to 100% again.

guitman32

iTrader: (15)

No effect on VDCfor daily driving, and you're gonna be turning it off on the track anyway. I still have the 615s on my track wheels, but will be replacing with r-comps as soon as time permits.

+1. I had a snap oversteer moment on my first autoX with the 615s, but I had the pressures wrong and was definitely overdriving the tire at the time.

MJM Z

I used this thread to do my research before ordering on tirerack so thanks for all the info everyone. But I just got an email from tirerack saying "according to their database 255/40/18 is 'short' for the car."

What does "short" mean exactly? In the mean time I'll call him back and see what he has to say.

terrasmak

iTrader: (8)

It means the tire is shorter than stock as noted in post #13

MJM Z

^^Edit, I called the guy and he said just the stockers come up in the database as acceptable tires so he just wanted to make sure i was 100% sure. So I guess it's a good thing but I've never heard someone refer to a tire as "short" before.

KuNoichi

The previous owner of my Z has:

225/40/18 front

275/35/18 rear


stock for my touring is:

225/45/18


245/45/18

According to this calculator: http://www.1010tires.com/TireSizeCal...?action=submit He was very wrong. I don't know how long he was running this setup but should I expect damage or inaccuracy with my VDC now?

terrasmak

iTrader: (8)

VDC couldn't even care. you have the proper stagger in tire height between front and rear. Now handling will suck, but most don't care about handling for some odd reason.

KuNoichi

Why do you say that the VDC doesn't care? How do you figure? The rear set has a circumstance of more than 3%.

What am I missing?

davidv

iTrader: (2)

TireRack is very conservative about tire sizes. They just don't want you returning tires because of fit or VDC problems.

davidv

iTrader: (2)

You are running a 275 mm tire on a 8.5 inch wheel? That is one fat tire!

KuNoichi

I don't know if this aftermarket wheel is 8.5.. but, yeah, the tire is really fat and it's wrapped around a heavy deep lip wheel. Looks cool but not really functional.

I actually have a set of wheels that are:

front:

18x8.5 +25 offset


rear:

18x9.5 +30 offset


In the front I want 235/35-40/18 and a thicker tire with a higher profile in the rear - 265/40-45/18. I know the wheels can handle the tires per this site: http://wheelsmaster.com/rt_specs.jsp

but will my VDC be ok?


My previous stock sizes were:

225/45/18

245/45/18

MJM Z

Just got the new tires put on. Going forward, do I use the same PSI guidelines shown inside the driver's side door, or does the proper PSI level change once different tires are used? I didn't see anything about this on tirerack.

terrasmak

iTrader: (8)

VDC will hate you. If you want to run a 265/40 rear , look into a 245/40 front.

KuNoichi

Right. Considering VDC and my wheel sizes, I'm going to run a 235 - 255 setup. That's good enough for a DD.