Okay, I've been looking into this for a while now and I'm almost complete convinced that there are currently no 18" wheels and racing tire combination out there that would allow me to stay in stock class. If anyone is attempting to do the same, I'd like to hear what you've done or have found out.

Looks like 17" wheels and tires are the way to go since most of you guys have them but doen't look like you're running in stock classes. I'd like to hear what some of you guys that are running in SCCA Stock B class are using. I'm here in Washington where aside from myself, there's only one other guy running in SCCA-NWR (Northwest Reigonal or WWSCC (Western Washington Sports Car Club) autocrosses and I'm the only one attempting to stay in stock class.

I'm ready for a set of dedicated racing tires cuz I'l like to give those S2000 guys a run for their money. 2 of them are currently dominating the stock class that I'm in running in the WWSCC series. I'm running on the pathetic Bridgeston RE040's right now. I've messed with the tire pressures and it looks like I'm not going to get any more out of these. I just need to make up 2 more seconds and then I'll be competative. I know that seat-time is what really matters and the more I can get the better but some R-compund tires would really help in getting there.

 

If you are looking to stay in stock class with your Performance, then you won't be able to use the 17" wheels...at least not in the SCCA (the WWSCC rules may be slightly different). At the local level, your competitors may not mind you using 17s that are the same width as the Enthusiast or Base (best to ask them first though). But you would run the risk of protest at a Divisional or National level event.

It would be safest to stay with the 18s and probably the best thing to do while you are still learning the sport is to get a set of stock oem wheels. You should be able to find some for sale on the forum.

 

If he switches all the performance mods that are on the Performance model to the enthusiast, then he would be eligible for stock class.

Also, you could run 265/35/18 Kumho Ecsta's front and rear. That would be the ideal and would cost around $700 to do. I had 225's up front with the 265's and couldn't stand the understeer!

 

The WWSCC rules for stock class are: any wheel size avaliable as a factory option for the make(ie: 350Z. Base, Performance and Track are options not models) from the manufacturer can be used with no more than +/- .25 inches (I know... they should have made it metric.) offset from OEM. The rules are different than SCCA.

Here's the URL to the 2003 rules if anyone's intrested:

http://wwscc.org/rules/2003rulebook.pdf

Section 4.2.3.2

I could go down to the 17x7.5 and 17x8. I'd like to know if anyone has attempted this yet and what were their selections of tires.

The way I see it it all comes down to what racing tires are avalible for what wheel sizes avalible for the 350Z. I could wait a few more months and see what comes out but it seems more like wishful thinking that a tire sizes from Toyo, Kumho, Falken, etc... will come out to match the OEM 18's. Or is it? Does anyone have any inside info from these manufacturers?

Since I'm out of the running for the championship this year it's a good time for me to experiment with the time that I have left for this year. I'm not willing to just toss a couple of $g's away for experimenting. I wish I could but like most guys this is a hobbby and I'm on a budget. So I need to do my homework first. Part of that homework would be to get info from those who are currently running with other tires in Stock class. Anyone willing to share their experiences or knowledge on the subject? I'd greatly appreciate it.

 

That would involve getting rid of VDC, though, as I interpret things (not that it is really used for autocross). That would be a difficult task

 

According to the rule book, the way it's worded it doesn't look like the VDC would be a problem. It seems as though it's only based on the OEM equipment avalible for that model. The VDC and TCS are performance killers. I never run with it on (when I can remember to turn it off), it can add as much as 2 second onto my time when I accidentally leave it on.

Hey, Zoasis... are you still running with the 265/35-18's all around? Are they on the Performance option wheels, the Rays or on some other after maket?

 

Unfortunately, back in the mid '90s there was a huge stink about this practice revolving around the Miata. It was heavily rumored (and there was some evidence that the rumors could be true) that there were more differences between the Miata models than Mazda made public. It was pretty much agreed that it would be nearly impossible to prove that all the changes necessary to go from one model to another had been correctly made. And since the burden of proof that the car is legal falls on the driver, it pretty much made any attempt to try to convert one model to another protest bait.

For local SCCA events, drivers can usually get away with little stuff like that. But at SCCA Divisional or National level events...forget it (unless of course you are running dead flat last).

 

A friend contacted SCCA National, and posted on 350zfrenzy.com about the specifics relating to different models of our cars.

Here is the link, with the definitive answers:
http://www.350zfrenzy.com/forum/show...&threadid=1550

Also, last issue of Sportscar magazine officially classed the Z in BSP.

 

94 and up stock cobra rims will fit the z and are 17 inch. alot more rubber to choose from in the 17 range. 18 inch selection sucks right now,
Just did a pro solo and the z has along way to go in BS to catch the s2000, personally I think and others at the same event felt the 2000 is in the wrong class, the rest of us where all pretty close time wise and the 2000 was 3 seconds faster.
john

 

I've heard they won't fit over brembo's though. buyer beware

 

FYI for you guys considering Kumho.

I called up Kumho to inquire about the Victoracers V700's. Currently they do not have it in an 18" tire and I wanted to know if there were any plans in the near future to produce one. I spoke to Aaron Smith, the Victoracers guy at Kumho. He told me that there are 18" Victoracers coming out in the following sizes:

225/40-18
265/35-18
275/35-18

He said that they should be avaliable by the end of this year or early next year. Prices similar priced (a little more of course) to the 17's. He said that the 225/40-18 could be used up front but I think they'd be a little small. The 265/35-18 seems like a lot of guy have already done and should be okay for the back.

He also mentioned that there would be another line of tires for autocrossing coming out early next year that will have 18" tires. I didn't get any more details that that but he did say it would be more agressive than the Ecsta V700's.

Anyone have any info from Toyo, Nitto and/or Falken about their 18's that will work on Z for their popular autocross tires? If so, I'd appreciate it since it would save me from having to contact them. Thanks.

 

Mustang rims will fit the non track 17 inch models just fine

 

If you change the wheel sizes then there are a lot of options for tires on the 350Z. My problem is that I want to stay in Stock class and that is where things get difficult when looking for tires.

 

Kumho Ecsta V700 has replaced the victo racer model, in 18 the choice is 225 or 265. The 265 fits the back and the 225 is to small on the front, but works if you adapt a little. Hoosier has a 245 but it is the R version, not the A for AutoX.
I usually run 34/33 back and 36/37 front, the ProSolo was on concrete and was 110 degrees, had to go to 44 front and 39 rear to get them to work, other wise the edges would grab, and sidewall would fold up.
If you have a non track model, the cobra rims are within the rules and you have a very wide range of tires to choose from.
The easiest way to battle the understeer is a 5 pound spread between front and back, I tried 29 one time in the back and the car was to loose for me, 33/34 works well in the back, 36/37 seems to work well in the front with the Kumho on a track model.
I also found sometimes you have to run slower in hard turns to retain steering, sometimes using small inputs vs a hard crank, drag brake too. I seem to do very well in offset slaloms and suck in long straight slaloms. My running mate is an 8 time National champ and is also having a hard time with his car.
Good Luck! John

 

I attended Evolution school last week (http://www.autocross.com/evolution) and that helped me bring my times up 4.5 seconds. I understand that you do need good racing tires but there is no substitute for knowledge. I considered my self pretty good driver but after going through this school I am beginning to see how much depends only on the driver and driver's habbits. I loved the school and all the rest of the people there did too. I will be definetelly attending it again for more advanced classes, compare to all the other schools this one is very well priced.

 

MadMax76

I would've loved to have gone to the Evolution driving school, but they only offered it on a weekday. I guess that's a lame excuse on my part, though.

Hey, did you get a chance to talk with Glen "The Hurricane" Hernandez. He was one of the instructors there this year. During a practice session 2 weekends ago I let him take my Z for 2 runs.

Check this out... The best time on the course that whole day was in the mid-32's (I think it was Glen's who go it in his Porsche). And there were some serious guys there with their trailed racers. I had a tough time trying to break 38 out of 8 runs for the day. I let Glen take my Z on 2 runs. Keep in min that this is the 1st time he's ever driven the 350Z and I'm in the car with him (+150 lbs). On his 2nd run (Clean) he got a 34.6! "Holy high-performance machine Batman!"

My car is a bone stock Performance with those crappy RE040's on it. After that I was convinced that the 350Z is an incredible machine, but takes an incredible driver to bring out it's potential. I am far from there and there's a long, long, long way for me to go.

I'm hoping to go to some driving schools next year, I don't think they'll be anymore this year. But until then, seat-time, seat-time, seat-time.

 

This weekend, it'd be interesting to let Glenn go without a passenger...

 

BA Cutler!

Good to see you here. I take it that you've been observing my mad quest to find competion tires for the stock wheels? A co-worker suggested something that may turn up something. Since they've had the Fairlady Z out for almost twice as long as the 350Z, it might be possible that some of the Japanese tire manufacturers might be selling correctly sized tires on the Japanese market. So... I got a friend of mine that is fluent in Japanese to look into some of the Japanese websites for Toyo, Yokohama and Nismo since I can't read Japanese. I'm hoping that it might turn up something. Yeah, it's a long shot but might as well keep looking until someone (hopefully Toyo) comes out with tires that match.

 

Guys, won't the 265/35's fit up front as well as the rear???

I've been kicking myself for not trying this with the track wheels I previously had and sold because the 225/40's up front were way too small IMO. I'm running 275/40/17's up front right now so I'm sure the 265/35's will fit with no problems. In fact, I'm now thinking that 18's may be better than 17's since the sidewalls on 275/40's are a bit tall. Not for sure though since I haven't really been able to autocross it hard with full brakes yet(brakes went to floor on Sunday due to air in the lines)

 

zoasis,

Are you suggesting running 265/35's all around? I thought about doing that w/ 245/45's I'm not sure what raising the front by 1/2 an inch would do to the dynamics. The wheel wells seem plenty wide so the 265/35's look like they could work too.

Any one have any knowledge or opinions on running 245/45-18's on all 4 corners?