I am toying with the idea of getting a used set of stock wheels to mount some decent rubber to use for AutoX/Time Trials events. I am talking about using good 140 treadwear tires, like the XS. I am looking to get this on the cheap, so wheel look/condition is not a big concern. This is to have better rubber for the events without destroying my rubber I use for daily driving. I have a 2006 touring roadster with the 5 spoke 18" wheels.

Question is my stock rims are 8" wide in the front, 8.5" wide in the back. I want to run a non staggered or square setup with the track wheels. Can I run the same size tire on these rims, and what would be the largest size I could safely run? Can I also run pre-2006 rims as well? Any year model rims that would not work?

I have searched last night and there seems to be a lot of opinion on what size can be run on certain width wheels. I have the stock 225/245 tire setup now but I was hoping I could go larger with the idea of more traction for these events.

 

I have a spare set of stock wheels I used all this season and most of last for autocross. They performed great, and though they're not the lightest things out there, they're pretty strong and not too heavy. They can also be had cheap (I picked mine up with used V710 race rubber on them for $400 total).

As far as I know, you can run any rim from any year/model of the Z--the wheel wells are all the same, and the offsets/widths should all fit. You can also fit 255 width XSs on all four corners on even the 7.5/8" stockers with ease. I know, because that's what I ran for about 4 months this year. Not exactly ideal, but for a cheap/fairly high-grip setup, it's pretty good.

I might recommend some other tires besides the XS, though. My experience with them is that they are very good at maximal grip in the dry, but not very responsive, pretty terrible in the wet and not especially great in longitudinal grip. The Dunlop Direzza Star Specs are much better in the wet, priced about the same, and offer a good bit stiffer sidewall. They don't like heat as much as the XS though.

Hankook's RS-3 is also better in the wet and transitions, likes heat a bit more, and offers very good dry performance. The last tire I'd suggest is the Nitto NT-05, mostly because they have very stiff sidewalls, run fairly large for their claimed size and love heat (i.e. they're probably the best trackday street tire of the group in terms of wear per unit grip).

Anyway, my $0.02. Hope it helps.

 

So I guess 265's on the newer wheels are not out of the question. Thanks for the reply, I met you in October at Pennington field in Texas at my first AutoX event. I was there yesterday for my second AutoX event sponsored by the S2000 group. I also ran a time trials earlier this month and really enjoyed the format and much higher speeds. But the wear on tires and brakes I can tell is much more than an AutoX. but I still plan to do another in January.

I realized the weight of the wheels is not the lightest but I don't think I will really ever be super competitive in my class because of the weight of the roadster. But I am mainly trying to improve on my driving skills over the next year and see where it goes from there. I already can't wait until the next event, keep replaying the course in my head from yesterday thinking how I could have improved my lines.

 

Oh yeah, I remember meeting you. Sorry, I'm pretty bad at connecting faces to screen names.

Glad to see you're having fun and sticking with it. These are super fun cars to drive even if they almost never class competitively for one reason or another.

265s should be doable on 8-8.5" wheels, no problem. Might get some odd wear depending on the tire, but any compromise setup will have its downsides. I wouldn't worry about it.

 

For SCCA Solo (autocross) stock classes, you need to keep the same size wheels as stock, which for yours would be 8" front and 8.5" in the rear. That doesn't mean that you need to keep the same size tires as stock.

On my track wheels (which are the same size as your wheels), I run 285/30R18 Kumho V710s or 295/30R18 Hoosier A6s. The Hoosiers are easier to get mounted than the Kumhos -- believe it or not -- but the Kumhos last longer.

However, for non-R-compound tires, I'd still stay "square" on the tires -- 275s all the way around (35 or 40 profile).

 

Will 275's fit in the fenders without issue, everything is stock right now.

 

FYI I'm currently running (4) rear 18x8.5 track wheels (+33 offset) with 265 RE-11's all around. Perfect neutral feel for autox. Slightly scary on the track though lol.

You don't necessarily need to fit the widest street tire on the wheels, because street tires don't have as stiff as sidewalls as the R-comps (I think) so you may actually lose performance. I'd just go with the ideal size for the wheel.

If you want the neutral feel with 18x8's and 18x8.5's I'd probably go with 255's all around, crappy thing is only Falken makes the 255/40 which would match stock size (to keep your rpm the same so you don't run out of gear too early). Other than that you'd have to go to a 265/40 which is pretty close to stock size, but may stretch a bit on the 8" wheel.

 

I've run 295/315s on 10" wheels all around. 275s fit with ease.

 

I read the Oct issue of SportsCar magazine too

 

Some of that definitely comes from there, some of that is my personal experience too. Haven't driven the 'kooks yet, though.

 

I'm perpetually confused. I have three sets of stock wheels (I know, a bit silly). I have a set of 18" v.1 Touring stockers with AS tires on them for the winter. I have the v.2 Track wheels that came with my 2006 GT, and I picked up a set of v.1 Track wheels recently. My thought was to use the v.1 Track wheels for Autocross because they are so nice and lightweight.

So, one question is that my GT came with the 18x9, 19x10 wheels. Can't I put the v.1 Track on with the 18x8.0, 18x8.5 and still be stock legal? Likewise, could the OP run 18x9, 19x10 since the v.2 wheels were available for his 2006 year?

I'm still trying to decide on what class to try and run in. Not that it matters as I'm a slow driver anyway, but if I remove my spacer and put back my stock plenum then I could run CS instead of the BSP I'm in now. However, if I wanted to try the new STR, then I would have to limit my tire width to 255. In that case, I might go with 245/255 or 255 square with the v.1 Track.

 

No, you gotta stick with stock size wheels to your exact year, model, and trim level.

 

^ correct. However if your car is a GT which means you have the wider (19x9 I think?) in the back and 18x8.5? In the front, I don't think anybody would care (especially at regional level) that ur running a SMALLER width wheel with the v1 track wheels.

However nationals may be a different story

 

Thanks. Yeah, the v.2 are 18x9 in front and 19x10 in the rear. There is a big difference in the rear wheel weights however between v.1 and v.2.

 

Is there any disadvantage to running the 17" stock wheels vs 18". Will this throw me out of stock class? Will the smaller tires cause me issues with TCS/VDC if I forget to turn it off while driving to the event? The early Z/G wheels are 17", not 18"

17" wheels make getting tires cheaper but I was not sure if it would cause problems. My car is a 2006 so it came with the 18" 8.0 and 8.5" wheels.

 

In order to remain in stock, you need to run the same size wheels that came on your model.

 

So if I went with 17" I would be in BSP?

Tires for 17" wheels are about $300 cheaper per set vs 18" wheels

 

like I mentioned before, if ur competing locally, nobody will care (which I'm sure you are since you're asking this question)

Keep in mind the stock 17's are a lot narrower than the 18's which will limit to how wide a tire you can run

 

Yes, It would be competing locally, probably not even running every event of a series but I will just have to see. There are several groups that run here (5 I can think of) so I have a lot of opportunity to run, I could probably get 255's on the 17" but that seems to be the biggest available for that size wheel. Probably still better than the 225/245 setup I have now.

However I am going to look at a set of 7 spoke G35 coupe v.1 18" wheels this weekend. I would assume they are like the 350z touring v.1 wheel but maybe a little lighter from my research.

 

Well I purchased the 18" G35 7 spoke wheels today. They are very similar to the 6 spoke touring Z wheels in that they are all 4 8" wide with 30 offset, but I think they are a few pounds lighter.

Only difference in my stock wheels vs the G35 wheels is that my rear stock wheels are 8.5" wide with a 33 offset.

I actually kinda like the G35 wheels on the Z, I may make them my daily driver wheels and use my stock wheels for AutoX/Time Trials. Also thinking about going with square setup on the track wheels and the street wheels. What do you think about that? Anything I am overlooking?

Here is a picture of another car with the G35 wheels (not mine)

https://my350z.com/forum/members/wal...35-wheels.html