Which track setup should I run of these two?

[dogunbound]

I want to run my OEM wheels on the track since they are forged. While shopping around, I saw the Dunlop Direzza ZIII on sale and would like to get a set of ultra high performance summers for the track on the cheap. The only issue is that there are only two sizes in 19s that are available:

245/40R19
275/35r19

I will for sure run the 275s on the rear. What I'm more worried about is the front. According to the manufacturer, these are the rim width ranges acceptable for the tire:
245: 8-9.5"
275: 9-11"

So fortunately, both sizes can fit the fronts. The only issue that I would have with running the 275s in the front is possibly rubbing the knuckle. But if I run the 245s instead, I have less tire on the ground. Anyways, that is why I am contemplating getting the 275s for the front wheels.

What do ya'll think? Maybe I should just run the 245s for the front. Thanks!

 

[VR30Infection]

I’m assuming you are on 9.5 front and 10 rear performance rims? If so. If it’s for the track only, then my vote will be for 275 square. The z is a front heavy car. It likes a square setup for track.

 

[trackratZ]

275s might fit up front but know that with that much more tire width you'll get way more oversteer. The Z is already snappy tail-happy as it is stock. Best maybe use square 265s to balance out, or just use close to stock sizes. Square setup is always nice if possible to save tires by rotation.

 

[VR30Infection]

I guess there is more than one way to skin a cat. Typically for the track you want as much tire as you can fit up front and then match the back for a neutral to loose car and then 1 step wider in the back if you don’t want it loose. (Front engine rear drive) With the 9.5” rim up front and the 10” rear there would not be any rotations being done. I am definitely not the authority in the matter however. If it were me choosing a good tire for the stock rims I would go 275/35-19 Front and 285/35-19 rear. I would just look for a tire that had both of those sizes available and had the right treadwear rating for the job. Or. Maybe pick up a set of rear take offs from someone and run the 10” square with 285’s.

 

[dogunbound]

Decided to run 275 square. I hope everything fits well

 

[trackratZ]

Decided to run 275 square. I hope everything fits well

Good choice, if at all possible for frequent tracking have a square setup, will save you $$ long term. You can always adjust swaybar settings to balance out handling. What wheels and offset are you deciding on, fender rolling?

 

[dogunbound]

Good choice, if at all possible for frequent tracking have a square setup, will save you $$ long term. You can always adjust swaybar settings to balance out handling. What wheels and offset are you deciding on, fender rolling?

Oe wheels are great since it’s forged.

no fender rolling

 

[trackratZ]

Oe wheels are great since it’s forged.

no fender rolling

OE Sport wheels or Performance? Performance can't be rotated, different sizes and offsets. Sport can.

 

[dogunbound]

OE Sport wheels or Performance? Performance can't be rotated, different sizes and offsets. Sport can.

The performance ones. While they can't be rotated, that's A-OK. You can just replace the tire once it's bad per front/rear. Also, you *could* run 10mm spacers if you really wanted to be able to rotate them freely.

 

[VR30Infection]

Yeah. In the future it would be good to grab a second set of performance rear wheels so you can