Hey guys. So now that my winter tires are basically bald, I have an extra set of oem wheels. And since I have the B13 now, I don't drive the Z in the winter.

I was thinking of putting new tires on the rear and running them up front for AutoX.

What do you guys think of this setup over the standard staggered setup.

My car is stock and I run in the CS class.

By the way my current wheels are 08 base and my winter wheels are 04 touring, which are also 18s. Not sure if they are the same offsets.

Thanks!

 

Hm. Surprised that this topic isn't easily found .. by searching for 'square' in here. There is a three year discussion in the wheel/tire section..

https://my350z.com/forum/wheels-and-...questions.html

 

I saw this thread but it mainly involved 10.5 x 10.5 setup. I would be running 8.5 x 8.5 setup so I was wondering if anybody ran the same. I will go again through the thread though.

 

That thread is really about what size wheels and tires they should get, mostly 9.5 to 10.5 wide wheels. I already have my sizes.

 

I ran 245/40/18 square for a couple years (on 1st gen track package wheels) and used for autox/hpde. I was happy with the setup and preferred it over the stock stagger. In my experience, it made the car more neutral (to be expected) but unltimately just wasnt enough tire for the car, especially in the front. I'm now running 275/35/18 square and plan to continue with a square setup for the foreseable future. I also had the Hotchkis springs/sways during the staggered and square setup for full disclosure.

Hope that helps.

 

Thanks for the response. I do want a more neutral car as I feel the Z wants to step out quite a bit. Then again my tires were shot last season. Got new tires for this season. I guess I will see how the first session goes an decided whether I want to run square or not.

 

I used to asked this question month ago. I was told that the square setup will reduce the understeering which is our car original induced. I ran 245/275 with NT555 last year, it was a lot understeering (stock suspension and open differential), I ran 245 square with RE-11 and Quaife LSD, the car feels totally different, but I won’t give much credit to the square setup (I am not so experienced, actually cannot tell from the stagger vs square).

Regarding the tire width, this is what I recently learned: with the same tire pressure, the contact patch for skinny/wider tires are the same, the difference is skinny tires may give you more support when you accelerate, but wider tires will give you more support during high speed corner.

 

Hmm. Maybe it would be better to keep the stock setup then, since I am also stock suspension and open diff. I would rather be able to rotate the car with oversteer then understeer in the tight corners.

I might still use the winter wheels for the track, but maybe just as dedicated AutoX tires.

 

A suggestion from novice to novice autoxers (may be not apply for you SQuaLZ, but may useful for other new autox drivers).
If you are new/ have couple times to autox, I would suggest to use all stock parts. I made the mistakes in my previous autox but didn’t realize. I tried to beat my time each time and chased those who were faster than me instead of focusing more on how to drive the car. My time is OK, just 1-ish sec more than instructor drove my car (he drove hard, but I believe he will beat few more sec when he familiars my car), but I didn’t realize all my did is rough driving – wiggled the steering wheel very hard, brake late and brake hard and etc, until last month. I will switch back fromo RE11 to NT555, or may even use 235 square cooper RS3 for my next autox. So learn and practice with the stock car, feel it and start upgrade one part per time when you are comfortable to handle the stock. Compared with the result, learning is more valuable for $60 and a whole day.

 

Good point. I am novice in terms of AutoX, and I agree with you. Last year, once I stopped worrying about my time compared to other drivers and just worried about my driving, my times dropped immediately.

 

No 350Z was shipped with an 8.5 x 8.5 setup, so running that setup would take you out of stock class.

However, that doesn't mean that you can't run a square tire setup on an 18x8/18x8.5 (if your car was delivered that way).

 

True. I don't understand the classes sometimes. I feel like when I go there are several cars that are in classes that should be in higher classes. The rules are very weird in my opinion.

So stock class means 100% stock? I believed there was some wiggle room, just no suspension work, anything in the engine that is more than a simple bolt-on, body aero, and wider wheels.

I thought I would get away with it since they are still 350Z wheels

 

Stock is still a preparation level (renamed "Street" next year, as part of a way to denote that it's a prep level).

Stock permits changing one anti-roll bar (front or rear) and parts that could wear out over the life of a car (shocks, cat-back, fluids, filters, brake pads, tires) with higher-performance parts, and also some comfort & convenience items (stereo, indicator lights). Other parts must be stock or equivalent -- and they must be installed in the same location and orientation as delivered by the factory or not marked in the FSM as "for competition use" -- for example, while you can turn the upper shock mounts on some Porsches and it's permitted in the FSM, it's for competition use, so it's disallowed. Another example is the camber bolts delivered with the Hyundai Genesis R-Spec -- the stock bolts were delivered installed and the camber bolts came as a part of the car but were marked as "for competition use" and were not legal.

The stock rules can be confusing sometimes, and regionally they're not always strongly enforced unless someone complains. Even nationally it's important to know what is legal -- or not -- on all of your competitors' cars. That's actually one of the reasons that possession of your car's Factory Service Manual(s) is required at national events.

 

Thanks for the clarification!

This makes alot more sense now. So now I can go ahead and buy the Nismo S-Tune Coilovers and still run in the stock class. I was worried about being bumped up into a class I would get my *** handed to me in.

 

S tune springs will not be legal in stock.

 

So shocks are legal to change but springs are not?

 

That's correct. Shocks wear out under "normal" usage, springs do not.

In the "early" days of autocross, most cars didn't come with anti-roll bars, and in the name of safety anti-roll bars were allowed to be added or changed to help to prevent roll-overs. That's the only "non-wear" item allowed in stock -- well, that and wheels since it's kind of hard to dismount and remount tires on-site...

 

Gotcha, thanks everybody for the help!