Hello All i recently just picked up my 06 350z and planning on making a track setup. I recently picked up some 18x10.5 +22 wheels, on a squared setup, and not sure if i should go 265/35 or /40? Any tips or advice would be appreciated.

 

Go 265/35-18 front and 265/40-18 rear,

 

275/35-18 all around

 

Fight, Fight, Fight, Fight!

 

275 or 285 all the way

 

Here are the contenders in the fight for the title (with their rolling diameters)!

265/35-18 25.30"
265/40-18 26.35"
275/35-18 25.58"

Now here's the judges scoring criteria.

OEM Sizes and Diameters
225/45-18 25.97"
245/45-18 26.68"

What's that tell you? It's a draw! They all suck!! Hahahahaha.

But seriously, terrasmak has been running that square 275/35 for a while it seems and it works for him - on the track (I think). Spike, OTOH, has been running his stagger set up on the street and it works for him.

That didn't help did it? Laff.....

OK, throwing my hat in the ring, I'll say this: if you're insisting on a square setup, 265/40-18 square. Why? It sits almost exactly in the middle of the OEM stagger. (and the 35 aspect tires are just too short - although in a track application like terrasmak's, it's not that big of an issue ). If you don't have a trim level that has VDC, you should be good. If you do have VDC, I'd consider at least a nominal stagger just to keep the ECU happy.

On 18s, MY preferred setup is 255/40 & 275/40. Almost identical rolling diameters to OE and a very good uptick in ultimate grip and steering attitude (increase in front size cuts understeer from stock quite a bit) then, further tuning of steering is/should be through roll stiffness adjustment.