Sticks n Stones

First thing first: The Dunlop Direzza Z1 Star Spec and ZII are the bleeding edge of performance for Dunlop. These are the tires that hard core track guys run, Max Performance Summer Only tires with the traction (and probably tread compound) of a drag radial with stiff sidewalls of a road race tire. The most popular DOT compliant track tire in the world by a long shot. You gotta heat them up like a drag radial to get them to stick, but unlike a drag radial they shed heat quickly so don't do your burnout then wait to long to stage!

As you Star Spec lovers out there probably already know, Dunlop has updated the Star Spec and now call it the ZII. Pros and Cons of both with comparison videos of me racing a friend of mine before and after included - just remember the Star Specs I had on during the race were close to wear bars and were heat cycled enough (40k miles) that traction was not nearly as good as new.

Sizing and actual sizes: Star Specs were famously over sized for there ratings, with the my favorite 265/40/17 actually measuring out similiar to 285 width from other manufacturers. This was done for tire size limited racing series I assume. No more though, the ZII is now more accurately sized to its competitors. Lots less options for 17" rims too, with the 255/40/17 being the widest offered for a 17" rim. This 255 tread width measures out to 8 7/8" on my stock 8" rim while the 265/40/17 measures 9 7/8" on my friends 9" rim on his Z28 in the race vids. Below is the new sizes available. Prices are up by around 15% also.

SizeServ. Desc.
215/40R17 83W
215/45R17 87W
225/45R17 91W
235/40R17 90W
235/45R17 94W
245/40R17 91W
245/45R17 95W
255/40R17 94W
225/40R18 88W

SizeServ. Desc.
225/45R18 91W
235/40R18 91W
245/40R18 93W
255/35R18 90W
265/35R18 93W
275/35R18 95W
285/30R18 93W
245/40R19 94W
275/35R19 96W

Cornering feel and grip:Ultimate grip would go to the Star Specs if both tires were new I'm sure (1" tread difference is huge), but with my worn Star Specs against my new ZII's it is a tie that only a G meter and a skid pad could decide for sure. Feel goes to the ZII hands down, truly was surprising how much more feel I get out of these tires as compared to the Star Specs which always felt a bit numb.

Acceleration: Vids shown in my second post are of me on heat cycled tires, if the Star Specs were new also I would give the Star Specs the edge.

Rain traction: Star Spec wins easily in a straight line, though the Star Specs were scary when cornering because when they did break loose, there was no warning of it and they would snap loose fairly violently. ZII gives much more feedback and lets you know when you are approaching there limits - though there limits in the wet are lower then the Star Specs.

Miscellaneous: ZII's squeel when spinning, leave dark black marks that stick around for weeks, and are already showing noteable wear with only 4k mostly freeway miles on them. (dark black marks and wear *might* be related...) Star Specs did none of the above. Bet I get alot less miles out of the ZII's.

Sticks n Stones

Vids before and after the ZII install. Pay only attention to the dig aspect as I gained top end power with my Svede CAI install as my Vararam was causing MAF cavitation issues over 5600rpms.

Worn 265/40/17 Star Specs versus fairly new 265/40/17 Star Specs

New 255/40/17 ZII versus fairly new 265/40/17 Star Specs