I have read every post I can find on the "proper" rim and tire setup for auto-x with track days. I have the h-sport rear bar, camber adjustment front/rear, springs, koni shocks the "dreaded" SM pulley.

So I have 16" SSR Comps with some S03's that are down to the wear bars and then some.

So what do I do? I need to get some dedicated track tires (I MUST be the fastest Mini even if I loose SM :smile: )

Do I get some 15's with Kumho/Hoosier (victoracers/Ecstas/RS04's)?
What rim? I have tried to find some used spec miata rims to no avail. It would appear that 15x7 or 15x8 is the best way to go.

Or do I just use my SSR's in 16" as my race rim and find something cool for the street? What size street rim gives the most choices in tires? Does a 16" rim give me more choices for a competition tire?

As I said, I have checked as many posts as I could find and did not find a conclusive answer.

I would appear that 15" hoosier track compounds are the best choice for my adjustable cambre, but there is the wear problem. Although I have read about people getting a full season out of them. Does my tracking help or hurt them?
What I do not see, are anyone running 16" rims for competition; but there are not that many competition tire posts.

If you have read this far, thanks, you input is needed and welcome.
Ubercooper, I eat M3's on auto-x

 

Try some 15x8 Volks w/205/50 15 Hoosier R3S03s or 16x7 SSRs w 215/40 Hoosiers.

 

interesting, is there a big time difference between 15's and 16's? If I didn't need new 16 inch tires for the street, I would totally go for the 15 inch racers, but since I need 4 race tires, 4 street tires and a set of rims, I am tempted to get some 17's for the street and race my ultra light SSR's. But I 15's are so light to start with, I might be able to save some rim money on race 15's and burn my money with hoosiers.

 

It's all about the tire, not the rim. Pick the best tire size that makes sense and then decide on a rim to put it on. In your case though it's hard not to make use of the light weight SSR 16's but here is my $.02

S04 sizes that would work

225/45/15 22.8' dia
205/45/16 22.8' dia
225/50/16 24.6' dia

S03 sizes that would work

205/50/15 22.8' dia
225/45/15 22.8' dia
215/40/16 22.7' dia
225/50/16 24.6' dia

If your really looking for the best performance I would go wider than a 205 so let's eliminate those. The 40 series tires have a very low load rating so I'd eliminate those also. That leaves us with the following:

225/45/15 22.8' dia
225/50/16 24.6' dia

The MCS will be underpowered in SM so you would be better off with the 15's and the 225/45/15 in an S03 or S04 because of the reduced rolling diameter. You'll get better off the line performance and better gearing for the course to improve acceleration between corners where the higher HP cars have the advantage.

I went thru this thought process myself and that's why I got the 15's. I'm poor (read - I have wife and 3 kids and limited allowance) so I can't afford dedicated race tires but I my intent was that I'd eventually get some 225/45/15's Hoosiers to replace my Falkens somday.

 

Awesome!

This has always been a fear of mine, apparently size does matter.
So 15's to get the lower circumference, that turns this into a no brainer.
Man I wish I didn't own those 16" SSR, it is just too tempting, but then I loose the gearing advantage of the 15's.

Now to try and find some, good, cheap, lite 15" race rims and some decent 16" street tires.

Thanks,
Ubercooper

ps if anyone can tell me a logical reason to race the 16" SSR's instead, I am all ears.
s

 

The other big advantage of the smaller rolling diameter is that you'll be less likely to rub, but be very carefull with offsets or you may rub the front inside wheel on the strut or the rear wheel on the suspension arm. We had this discussion in another post about offsets. I went with a 15x7 with 40et and I have about 1/2" clearance from my tire from my tire to the strut with a 205 tire and even less between the rim and the rear suspension arm. I should still have clearance with the 225, but just a tiny bit. Would 42et work or 44et? I don't think 44 would but 42 might be perfect. Tires vary so much and width will change base on rim width so It's really trial and error. Best get advice from someone who has installed 225/15's. Obviously you want to get the wheel/tire as close on the inside as you can to prevent rubbing on the outside, especially with a 225.

_________________

 

I'm in the same boat. After much research I'm going with a lightweight set of O.Z. Superleggras in 15"x7" with 225/50/15 Pirelli Zero C (i have a friend who works at pirelli, these are R Compounds). I talked with Randy at Webb Motorsports and he says that 225/45/16 set up will rub. So I went for the 15" route. I haven't tried them out yet but I have a friend who has gone with 225/50/15 Victoracers on 15x7 Kosei K1 Racing wheels and he said it's unbelievable. I would give Randy a call for some proper advice.

Amit

 

If you already have the 16" SSRs put 215/40s or 205/45 Hoosiers on them. You will have the same diameter as the 205/50 15s. 17s for the street just for looks.
Chris

 

Want to sell them?

 

Check with Pilo Racing or RDR to discuss clearances for the 225-50-16's. One of the favorites in this size is the Kumho Ecsta V700 or Victoracer. These guys are pros and driving the cars with the 225's.

 

Scratch the Hoosier S03's and try their newer S04's. I'm not sure of S04's availble sizes but its sure all the rave in both wear and traction... (if you thought those S03's were nice.... JB weld for the road )

 

>>If you already have the 16" SSRs put 215/40s or 205/45 Hoosiers on them. You will have the same diameter as the 205/50 15s.
>>Chris

I agree fully.

That said, I hope they are 16x7.5's. If they are 7's I'd be very tempted to get 15x7.5's if they are not. The new S04 Hoosier's are wider than the old S03's. With 16's I'd go for the new 205/45/16's rather than either size of the old tires.

I got the 15x7.5's because there is a better selection of 15" tires that fit a MINI than 16's and the 15's are lighter and have much less rotating mass.

Any 225 with tire on a MINI will be a tricky fit. It can be done but wider wheels, lowered cars and various wheel offsets and diameters will only complicate the issues. You would need the advice of someone who knows and cares to save you a lot of time, $$$ or trial and error. I have several posts on MINI2 covering this, that could save most people a bunch of trouble.

 

I got 15" borbets with 50 aspect Victorracers. Why...cuz they were cheap....350 the lot.....I will probably go with good years next.....ah like goodyear race rubber.....

 

I do have the 16x7.5 SSRs and took the rims off this weekend to take some measurements and tried to figure out how much room I had to work with. WOW! I have almost no room between my 205/50/16 Potenza's. Less than a figure width for the front tires. So the quest continues, I will talk with the Pilo and find out what he is running. I figure there is a perfect offest in 15" that will do the trick with the Hoosiers and if I can fit them, I should be able to fit less "optmistically" measured tires. This is actually pretty fun to try and figure out.

Some great sources for those bench racers
tirerack.com (learn all about how rim width effects tire width)
hoosier (they have the actully widths of their tires list, combine with the above information, you can figure out how wide that tire really will be)
The long and short is
for every 1/2 in the rim is away from the "measured rim" add/subtract .2 inches of overall tire width

this is for imformation only, if you f something up based on an internet post, you earned it.

Ubercooper

 

one thing to keep in mind is that the BS SS-03's are a little oversized.
my 205/50/16/s measure 221 mm on a 16x7 rim. (which would make
them 221/46.5/16 when new). Most other tires I measured were about
7-9 mm bigger than the stated section width when mounted.

by the way, what's the offset on your 16x7.5's?

_________________
Cristo ---- my brg/brg mc is: BLIKSEM

 

I am pretty sure the ssr's are a 42 offset, alex@tirerack doesn't seem to be a supporter of trying to fit the wild offest 15's on a mini. I am begining to the think the fastest I can get is my really light 16's with 205 hoosiers.
ubercooper

 

WOW! I have almost no room between my 205/50/16 Potenza's. Less than a figure width for the front tires.

What is wrong with that? Tire isn't going anywhere....at least not if everything is still sort of attached to the car

 

Nothing at all, just makes me realize that 205 is about the maximum tire I can fit, maybe a 215.

Having re-invented the wheel on this one:
Tire Size Tread Dia Circ Meas. Rim Section 7.5 section
P205/50ZR-15 8.0" 22.8" 71.5" 6.5" 8.6" 9.0
P215/60ZR-15 7.7" 24.9" 78.4" 6.5" 9.2" 9.6
P225/45ZR-15 8.8" 22.8" 71.5" 7.5" 9.6" 9.6
P225/55ZR-15 8.7" 24.5" 77.1" 7.0" 9.4" 9.6
P205/45ZR-16 8.1" 22.8" 71.5" 7.0" 8.6" 8.8
P225/50ZR-16 8.8" 24.6" 77.3" 7.0" 9.5" 9.7

The last colum is the estimated section width with a 7.5 inch rim.
The easy solution is the 205/45 16 on my SSR's. Given that 15x8 would require custom rims (kodiak appears to be the best) and they would be heavier than my SSRs, it is a weight vs. treadwidth discussion. It is possible that a 15x7.5 off the shelf rim could be found, but it would need some serious offset to fit that 9.6 inches of section width.

So, all I have done is "prove" bgarfield really, really knows what he is talking about. There was another poster, in another post that noted that it all came down to the 205 16 incher and the 225 15 incher. I think a 205 on a 16x7.5 will work better than a 225 on a 15x7 (ala kosei)

Ubercooper

 

Congratulations!! You get an A+ in Reasearch.

You may want to consider the 225/45/15 AVON Tech R's or the Kumho 710's when they come back out. Put them on 15x7.5, +43 SSR's but you will probably need a 1 mm to 2 mm spacer for the wheel to clear the rear trailing arm. The Racing Hart CP-035 comes in a 15x7.5, +40. Those 9.6" wide Hoosiers will need +39 to clear the stock struts.

 

Awesome, I will check that out, I just now realized how the math works with offset:

all width measurements are 1/2 their total value at the the centerline of the wheel
Offset is the distance from that center line to the hub face, so BAM
do all interferance measurements from the hub face to the struts/trailing arms and wheel wells, etc
use the section width from the tire mfg, and adjust the offest of the rim to make it all fit.

Of course for you pro's this was obvious, I apparently am a little slow, but it really does make fitting rims a lot easier.

Ubercooper

 

A word to the wise, call SCCA's Solo Technical Department and ask about classification for your mean machine......I am thinking you get to go into Modified....not SM. they will know though....no use getting embarassed at an event for mis classifying yourself.......

 

Has anybody actually tried the Avons? The tire information says they have a rounded edge for camber chalanged cars (stock).

The S04's will cord in front if the pressures aren't high enough (45-50 psi ?). I guess from what I have read the S04's have less rubber on the edges compared to the S03's.

Contingency money aside, which 16" tire would be a beter choice form a durability standpoint for stock class. Avons, Hoosiers or the V710 if it comes out later this year.

I'm running V700 Esctas this year but I'm looking at next season.

 

I have the 225/45 r 15 avons and they are awesome on the track, I have not autoxcrossed them yet, but I put 250 track miles on them and they looked almost new, two other guys were running the same tire and we all had great experiences.

On the track, they like lower pressures, like 33-35 psi, however I would start at 40 psi for autox and take tire temps at the end of the first run.

I ended up with with temps in the 150-160 range with 20 minute sessions.

 

Check this out:
http://www.ncr-pca.org/autocross/r-tires.htm

Interesting. I'm trying to answer the same question posed in this thread- want good track-only tires that will last more than 300 miles track/autocross. There's no simple answer I guess.

 

What is the max size tire you can run on the stock 15 cooper wheel? 205 50 15 it or will a 225 45 15 fit ?