It seems that 15" wheels are very popular in autox for Miata's and other sport compact cars. Would a 15x6.5 or 15x7 be the preferred setup for a Mini for best performance on an Autox track instead of 16" wheels?

I'm aware that this would not be allowed in stock class because of the size and width for MCS but I'm trying to determine what the best setup would be putting aside the rules for stock class.

So, I guess my question is would a 15x6.5 wheel with 205/50/15 tires be a better combination at 2-3lbs lighter or would a 16x6.5 wheel with 215/45/16 be the better setup for the track? The other deciding factor here is cost (this is all assuming lowest cost/cast wheels, not forged) there is a big difference between alot of 15" and 16" wheels for example the NZO monza wheels - 16's cost around $165 and a 15 only costs around 110. Also the tires are cheaper in 15's compared to 16's for example - Falken Azenis 15's are around $65-75 and 16's are around $100-110. So can someone help me deciede? 15's are a fare amout cheaper and lighter, but will I loose cornering performance over the 16" combination?

 

I can only think of one reason to go with 16"- Hoosiers 215/40 16s. 15s will give you lower gearing, less unsprung weight, and less expensive wheels and tires. I vote for 15s.

 

>>I can only think of one reason to go with 16"- Hoosiers 215/40 16s. 15s will give you lower gearing, less unsprung weight, and less expensive wheels and tires. I vote for 15s.

I forgot to mention in my post that this setup would be for Street tire setup for STS class type racing. Thanks!

 

For STS I would go with a 15x7 or wider... (I know there is a max rim width in STS but I am not sure what it is) even a 205/50/15 will like a 7in rim vs 6.5... as stated before the only reason to go with a 16 is if the 16inch tire offerings give you a much wider tread width... otherwise the lighter/shorter/cheaper 15" setup is the way to go!!

From chatting with local STX/STS guys the Kuhmo MX is showing promise against the falkens and BFGs.... so check out the size offerings on that tire too....

 

Good question!

I have the stock 16" 5 spoke star wheel / runflat tires that came with my sport package MC as well as a set of "take-off" 15" holey's with all season tires that I bought for winter use.

When I put on the 15" wheels last fall, I noticed that the car felt peppier and more responsive due to the lighter weight. I never did test their cornering limits.

I've been looking forward to wearing out the runflats so I can get some lighter, higher performance tires on the 16"rims. I'm hoping that I will get the peppier feel of the 15" wheels combined with the extra grip of the wider tires. Who knows, maybe I'd be better off with the widest performance tires I can get onto the 15" rims.

Thoughts?

 

PS I've only autocrossed once! It was a blast and I can't wait to do it again!

 

>>
>>From chatting with local STX/STS guys the Kuhmo MX is showing promise against the falkens and BFGs.... so check out the size offerings on that tire too....
>>

Yeap... been reading about that on the SCCA forums:

SCCA Forums

If you scroll down to the STS/STX Forum, you'll note there's a huge discussion on the Falken Azenis vs. the Kumho ECSTA MX. Seems like the MX's are gaining popularity, and evidently work better in higher ambient heat? At least that's what they are saying...

 

Hello, Super_MINI

The only reason to use the 16's is if you want to run in stock. I run 15's with 205/50/15 Falkens, and this is a great combination.

The only mods I have is the 15's so I run in STX, and I normally can out run the cars in G-Stock. This includes other S's running on R-compound tires. I am also very competitive with all the WRX's in STX. For reference one of the WRX drivers I run against is currently leading in the Tire Rack National tour.

The lighter weight is only part of the advantage of using 15's. The cost for tires is also much lower, and the smaller diameter actually makes the gearing on the S correct. With the stock tires the S is way overgeared. With the 15's the gearing is spot on, this includes normal street driving. One additional benefit is that I average 2 MPG better with the 15's VS the 17's.

Just my 2 cents.

 

Super MINI

I have two sets of 15" wheels & Tires for my MCS and autox both sets
15 x 6.5 NZO Monza w/ 205/50/15 Falken Azenis
15 x 7 Kosei K1's w/ 225/50/15 BFG gforce TA-KD's

The BFG sidewall is higher and we have had some bounce with this tire on bumpy courses.

The most value to performance is clearly the Monza 15" w/ the Falkens
The Monza 16" w/ the 215/40/16 is also a great way to go.

Of the 4 Cooper S's I know that compete in STX in the Mid-atlantic area 2 have 16" wheels and 2 have 15" wheels. And, if you have $ to spent the SSR Comps are the wheel of choice in either size.

You really can't make a wrong choice here between the 15 or 16 inch wheel.
In fact if you can afford it, get one set of each.

 

Thanks for all the responses. Anyone know what springs I should use with the smaller diameter 15" tire/wheel combination? I would like to do the H-sport springs but I think I may need to go lower because even with the H-sports I'll still have more wheel arch gap than I have now with my stock MCS and 17's.

 

dpayne1,

Do you have an pictures of 15" wheels on your car? I would love to see what they look like. :smile:

 

>>Thanks for all the responses. Anyone know what springs I should use with the smaller diameter 15" tire/wheel combination? I would like to do the H-sport springs but I think I may need to go lower because even with the H-sports I'll still have more wheel arch gap than I have now with my stock MCS and 17's.


First of all other than looks a wheel arch gap is not a bad thing... If you want to keep things simple and just use off the shelf spring sets like H-sport or H&R you are kinda stuck with the drop they give you... there are 2 other options.. 1 most would not recomend but here it is anyhow... cut a set of h-sport springs to give you the drop you want... (just make very sure to cut each pair (front/rear) exactly the same ammount!!! This is not for everyone but it is my feeling that cut matched set springs are ok... cut OEM springs are asking for trouble... BUT the better option is going to a coil over setup... more money obviously.... the coil overs give you more options... you can set the drop to about what you want, align the car (if you have camber plates) and then corner weight the car (do NOT skip this part) if you are not familiar with corner weighting try google as it would take a lot of space up here. also with Coil overs you can use just about any rate and length of spring you want (2.5" race springs like hypercoils/eibach ers) but remember any time you change spring rates or drop ammount or even camber on some cars the corner weights must be re-done....

On my last coil over equiped car I tuned my camber/caster, spring rates, and tire pressures before doing the corner weignts to save time and cash.... I now have a friend with electronic setup scales (big $$$$) but untill my Datsun Street Mod Project is done (and it will be a while) I have no need....LOL

 

>>dpayne1,
>>
>>Do you have an pictures of 15" wheels on your car? I would love to see what they look like. :smile:


Check this
Here

 

>>>>dpayne1,
>>>>
>>>>Do you have an pictures of 15" wheels on your car? I would love to see what they look like. :smile:
>>
>>
>>Check this
>>Here
>>
>>
:???: That didn't work - please send me a private message with you email and I'll send you a couple

David

 

Get 15's, and 7's would be a much better choice than 6.5's and 7.5's would still be some better than the 7's. There is a much better tire selection in 15's than 16's for STS/STX autocross tires that will work best with a MINI.

 

>>Get 15's, and 7's would be a much better choice than 6.5's and 7.5's would still be some better than the 7's. There is a much better tire selection in 15's than 16's for STS/STX autocross tires that will work best with a MINI.


Isn't the width limit for STS/STX 7.0"?

 

>>Isn't the width limit for STS/STX 7.0"?

No, the limit for STS is 7.5" and in STX it's 8.0.

 

I'm dealing with this same question. I'm leaning towards the 15" Monza wheels with 205/50-15 Yokohama 032R. I wondering how "autocross specific" this tire wheel combination would be. Would I be better off with 16" if I do 2-3 track days per year and want to use these wheels/tires? That would be the 16" Monza with 215/45-16 032R.

I'd like to end up with a combination that lets me compete in my autocross series here in Toronto while also providing me with the flexability to participate in lapping days etc. I could aways use my regular 17" with street tires but I figure if I'm going to invest in R-Compounds I'd prefer to use them when ever they make sense.

Paul

 

The Yokos are a bit slower than other r compounds on the auto-x course.. but are very good for lapping days and limited street driving (long lasting)... Autocross compound Hoosires are the fastest on the auto-x but would get torn up bad at a track event... Kuhmos would be a good compromise being fast at auto-x and a bit longer lasting for the track events... So if you are just out for fun at the auto-x go with the Yokos... if you want to be competetive at auto-x get the Kuhmos... To make matters more confusing there are a number of new r compounds coming out like the soft version of the Yokos.. the Hankook R tire and even a perelli.... (also geared towards track day type events not outright speed).....

 

>>The Yokos are a bit slower than other r compounds on the auto-x course.. but are very good for lapping days and limited street driving (long lasting)... Autocross compound Hoosires are the fastest on the auto-x but would get torn up bad at a track event... Kuhmos would be a good compromise being fast at auto-x and a bit longer lasting for the track events... So if you are just out for fun at the auto-x go with the Yokos... if you want to be competetive at auto-x get the Kuhmos... To make matters more confusing there are a number of new r compounds coming out like the soft version of the Yokos.. the Hankook R tire and even a perelli.... (also geared towards track day type events not outright speed).....

Agreed, it would see that the Kumho Victoracer are the best bang for the buck as far as good performance and longevity are concered. I'm going to be competing in the CASC Autocross series next year, which is like the SCCA event's in the US except Canadian. :smile: Because of existing mods (mostly the pulley) I'll be classed BSP or B-Street Prepared. This is what my car will look like:

H-Sport Springs
22mm Rear Sway Bar
15" Monza Wheels (12lbs)*
Kumho Victoracer 205/50-15*
H-Sport Camber Links*
H-Sport camber plates*
Koni Ajustable Dampers*
Rogue Intake
Magnaflow Exhaust
Supercharger Pulley
Forodo 2500 brake pads (or other)

Mods with a * will be done next year. My main worry is power, BSP is pretty mod-happy and even though that list looks long there isn't much their that gives me a ton of power. If I seem to be down in power after the first couple of events I'll look at the Evotech ECU upgrade and see how that helps. The 205/50 tires should help because that should give me a different gearing which should help the MCS accelerate. In CASC BSP I'm allowed prep points, the MCS is allowed 13 prep points in BSP. Each mod is assigned a point value. For example the pulley is 2 points and sway bar is 1 however you can doing anything to your suspension for a total of 4 points. The above list only totals around 7 prep points. The wheels and tires don't have any point value and are BSP legal mods.

It's all fun. I'm running the BMWCC autocross this year on the run flats and I'm regularly the 1st or 2nd front driver. Granted the Toronto area BMWCC autox isn't anywhere near as competitive as CASC SOLO2, but that's what I'm looking for, more challenge. :smile:

Cheers,

Paul