Please check my thinking - second set of wheels for AutoX and winter

[thom1033]

I picked up my new M3P last week. It's getting wrapped, tinted and ceramic coated right now. I've got a set of Signature wheels on order that I plan to run daily through spring/summer/fall. I live in Cincinnati, which gets very little snow, though some winter weather, and I work from home so don't drive a lot. I'm excited to get back into AutoX after a long hiatus.

My plan is to daily on the Signatures (20x9.5, 275 width PS4s). I need an alternative for the winters and would rather not run three sets (daily, winter, Autox). For the winter and Autox, I'd rather not run 20" wheels. I plan on running Super Stock class which allows for a 1" diameter decrease from stock as long as the wheel width is the same. For winter, I truly don't need snow tires but a good set of all seasons would be ideal.

My thinking is to get a set of 19x8.5" wheels (likely BBS CI-R, I've always loved those wheels) and get Michelin A/S 3s for winter duty (December through Feb/March) and then get a set of RE-71s that I'll have mounted on those wheels in the spring for Autox duty. I'd sell the stock 20" setup.

Per Tire Rack the CI-Rs come with a "centering ring", which I'm sure is a spacer to over come the lip on the P3D rotor hubs.

Any feedback from the gurus? I bought this car to get back into the modification and autox game and don't mind investing as it's why I didn't spend the extra on a Model S, I'd rather spend the difference on upgrades, though a $5k set of custom wheels as a secondary set is a little hard to swallow, otherwise I'd just get a second set of Signatures.

Thanks!

 

[Mash]

I think wheel wise you're going to be fine. But stock springs are too soft for autox and dampers are not right. And it doesn't make sense to buy forged wheels for autox either. Re71 will be overheating mid run in that size, especially without enough camber IMHO, but I never used re71 - they are not certified for EU. I just know that they warmup instantly and model 3 stock width is undersized.

 

[thom1033]

I think wheel wise you're going to be fine. But stock springs are too soft for autox and dampers are not right. And it doesn't make sense to buy forged wheels for autox either. Re71 will be overheating mid run in that size, especially without enough camber IMHO, but I never used re71 - they are not certified for EU. I just know that they warmup instantly and model 3 stock width is undersized.

I appreciate that. I should have mentioned I have MPP coilovers on order too. Camber is obviously going to be an issue and unfortunately not one I can correct with aftermarket and stay in the same class.. I *think* I should be able to squeeze a 255 width RE71 on an 8.5" wide wheel.

 

[SK360]

I run 255/40/18 RE71R on an 18x8.5, you’ll be fine. The BS National championship last year was won with a 265 on an 8.5” wheel.

Car needs camber so bad but I’ve been consistently in the top 5 for raw time all season. I wasn’t watching pressures too close last event.... oops. It was about time to flip them anyway lol.

 

[dsgerbc]

If you're into modding, a set of coilovers/camber arms is in your future. Do not buy wheels for the stock class you're gonna get bumped from.

For winter, A/S 3s aren't adequate. They are much closer to summer tires than to winter. I'd run something else, like crossclimates.

It seems like you want to swap two sets of tires onto the same wheel every season. That's...suboptimal.

 

[thom1033]

I run 255/40/18 RE71R on an 18x8.5, you’ll be fine. The BS National championship last year was won with a 265 on an 8.5” wheel.

Car needs camber so bad but I’ve been consistently in the top 5 for raw time all season. I wasn’t watching pressures too close last event.... oops. It was about time to flip them anyway lol.

View attachment 592062

Yikes! I appreciate the confirmation on the 255 on 8.5.

If you're into modding, a set of coilovers/camber arms is in your future. Do not buy wheels for the stock class you're gonna get bumped from.

For winter, A/S 3s aren't adequate. They are much closer to summer tires than to winter. I'd run something else, like crossclimates.

It seems like you want to swap two sets of tires onto the same wheel every season. That's...suboptimal.

Coilovers are on order (MPP sport). Camber arms bump me from SS, though it may well be a worthwhile trade off. I’m going to my first autocross in a long time with the M3 stock on 10/4. I think that will give me a better feel for where I am with the car.

Are the A/S 3s that bad in cold temps or slushy conditions? I’m a little biased as I grew up driving in the Wisconsin winters in light Honda Civic with cheap all seasons.

As far as the tire swap, it is suboptimal but seems more economical than running three sets of wheels...

 

[SK360]

Coilovers bump you from SS as well.

 

[thom1033]

Coilovers bump you from SS as well.

Is it because of the compression/rebound adjustability?

Here’s the language I found:
A. The make of shock absorbers, struts, and strut housings may be substi- tuted providing that the number, type (e.g., tube, lever, etc.), system of at- tachment and attachment points are not altered, except as noted below. The interchange of gas and hydraulic shocks absorbers is permitted. The following restrictions apply:
13.5 SHOCK ABSORBERS
1. No more than 2 (two) separate external shock damping adjustment con- trols are allowed. This permits the use of shocks which originally came with more than two external adjustments, which have been converted to double-adjustables, only if the additional adjustment controls have been permanently disabled (e.g., via welding, epoxying, grinding off). Gas pressure adjustment is not considered a damping adjustment.
2. Suspension geometry and alignment capability, not including ride height, may not be altered by the substitution of alternate shock absorb- ers. Aftermarket strut housings are allowed provided that they meet the Street category shock requirements defined herein (i.e., that no suspen- sion geometry changes result). This includes the position of the steer- ing arm attachment point in the case of struts with integrated steering arms.
3. Adjustable spring perches are allowed, but the spring loadbearing sur- face must be in the same location relative to the hub as on the standard part. Shims may be used to achieve compliance.
4. The fully extended length must be within ±1” (±25.4 mm) of the dimen- 2016 SCCA® National Solo® Rules — 71

13. Street
sion of the standard part.
5. Electronically controlled shocks may not be used on vehicles not origi- nally equipped with such units. Vehicles originally equipped with elec- tronically controlled shocks may use the standard parts or non-elec- tronically controlled

 

[SK360]

Is it because of the compression/rebound adjustability?

Here’s the language I found:
A. The make of shock absorbers, struts, and strut housings may be substi- tuted providing that the number, type (e.g., tube, lever, etc.), system of at- tachment and attachment points are not altered, except as noted below. The interchange of gas and hydraulic shocks absorbers is permitted. The following restrictions apply:
13.5 SHOCK ABSORBERS
1. No more than 2 (two) separate external shock damping adjustment con- trols are allowed. This permits the use of shocks which originally came with more than two external adjustments, which have been converted to double-adjustables, only if the additional adjustment controls have been permanently disabled (e.g., via welding, epoxying, grinding off). Gas pressure adjustment is not considered a damping adjustment.
2. Suspension geometry and alignment capability, not including ride height, may not be altered by the substitution of alternate shock absorb- ers. Aftermarket strut housings are allowed provided that they meet the Street category shock requirements defined herein (i.e., that no suspen- sion geometry changes result). This includes the position of the steer- ing arm attachment point in the case of struts with integrated steering arms.
3. Adjustable spring perches are allowed, but the spring loadbearing sur- face must be in the same location relative to the hub as on the standard part. Shims may be used to achieve compliance.
4. The fully extended length must be within ±1” (±25.4 mm) of the dimen- 2016 SCCA® National Solo® Rules — 71

13. Street
sion of the standard part.
5. Electronically controlled shocks may not be used on vehicles not origi- nally equipped with such units. Vehicles originally equipped with elec- tronically controlled shocks may use the standard parts or non-elec- tronically controlled

Look up the part about springs . A "prepped" street class car is generally shocks (If available as stock replacements), 1 sway bar and tires.

 

[thom1033]

Look up the part about springs . A "prepped" street class car is generally shocks (If available as stock replacements), 1 sway bar and tires.

Ah, gotcha! Thanks!

 

[dsgerbc]

As far as the tire swap, it is suboptimal but seems more economical than running three sets of wheels...

It's not. Buy used OEM take-offs (19" in your case), sell for not much less when you're done.

Tires aren't meant to be constantly mounted/dismounted. A good mount/balance these days is a couple of hundred bucks. Other cheap places will ruin the beads of your tires an scratch up your wheels after a few tries.

 

[SK360]

If you're going coilovers you might as well get the 18's and save some money and weight lol

 

[TwoK4drSi]

I picked up my new M3P last week. It's getting wrapped, tinted and ceramic coated right now. I've got a set of Signature wheels on order that I plan to run daily through spring/summer/fall. I live in Cincinnati, which gets very little snow, though some winter weather, and I work from home so don't drive a lot. I'm excited to get back into AutoX after a long hiatus.

My plan is to daily on the Signatures (20x9.5, 275 width PS4s). I need an alternative for the winters and would rather not run three sets (daily, winter, Autox). For the winter and Autox, I'd rather not run 20" wheels. I plan on running Super Stock class which allows for a 1" diameter decrease from stock as long as the wheel width is the same. For winter, I truly don't need snow tires but a good set of all seasons would be ideal.

My thinking is to get a set of 19x8.5" wheels (likely BBS CI-R, I've always loved those wheels) and get Michelin A/S 3s for winter duty (December through Feb/March) and then get a set of RE-71s that I'll have mounted on those wheels in the spring for Autox duty. I'd sell the stock 20" setup.

Per Tire Rack the CI-Rs come with a "centering ring", which I'm sure is a spacer to over come the lip on the P3D rotor hubs.

Any feedback from the gurus? I bought this car to get back into the modification and autox game and don't mind investing as it's why I didn't spend the extra on a Model S, I'd rather spend the difference on upgrades, though a $5k set of custom wheels as a secondary set is a little hard to swallow, otherwise I'd just get a second set of Signatures.

Thanks!

Having 2 sets makes sense and you can actually run 19x9.5 et35 squared for winters and track.

 

[MasterC17]

I would not recommend using the same set of wheels for winter and for track. It seems more like your daily's should be your track wheels. Tires are not intended to be swapped over time and time again, and it is not very economical in the long run either.

You can pick up some cheap wheels for the winter - Enkei or Konig are good options in 18" and 19". In fact, both brands offer good sizes for the track/AutoX at reasonable prices. The cost to mount and balance over ~2 years would exceed the cost of another set of wheels.

I would reconsider your tire width for daily driving if you feel like you will need the range. If range is a non-issue then go for it.

I have the following sets for reference, but we don't get any snow:

18x9.5 ET35 APEX EC-7 - 275/40/18 Hankook RS-4 (Track)
19x9.5 ET40 Konig Oversteer - 275/35/19 Federal RS-PRO (Track)
19x8.5 ET40 Konig Oversteer - 235/40/19 Hankook S1 EVO3 (Summer)
19x8.5 ET40 OEM 19's - 235/40/19 Federal Evoluzion ST-1 (Summer)
18x8 ET35 Enkei TM7 - 235/45/18 Michelin MXM4 (Winter/Long Range)
19x8.5 ET40 OEM 19's - 235/40/19 Laufenn S Fit AS (Daily for LR RWD)
18x8.5 ET40 OEM 18's - 235/45/18 Michelin MXM4 (Long Range for LR RWD)

 

[thom1033]

I would not recommend using the same set of wheels for winter and for track. It seems more like your daily's should be your track wheels. Tires are not intended to be swapped over time and time again, and it is not very economical in the long run either.

You can pick up some cheap wheels for the winter - Enkei or Konig are good options in 18" and 19". In fact, both brands offer good sizes for the track/AutoX at reasonable prices. The cost to mount and balance over ~2 years would exceed the cost of another set of wheels.

I would reconsider your tire width for daily driving if you feel like you will need the range. If range is a non-issue then go for it.

I have the following sets for reference, but we don't get any snow:

18x9.5 ET35 APEX EC-7 - 275/40/18 Hankook RS-4 (Track)
19x9.5 ET40 Konig Oversteer - 275/35/19 Federal RS-PRO (Track)
19x8.5 ET40 Konig Oversteer - 235/40/19 Hankook S1 EVO3 (Summer)
19x8.5 ET40 OEM 19's - 235/40/19 Federal Evoluzion ST-1 (Summer)
18x8 ET35 Enkei TM7 - 235/45/18 Michelin MXM4 (Winter/Long Range)
19x8.5 ET40 OEM 19's - 235/40/19 Laufenn S Fit AS (Daily for LR RWD)
18x8.5 ET40 OEM 18's - 235/45/18 Michelin MXM4 (Long Range for LR RWD)

Thanks for the feedback! I’m not worried about range, fortunately. I’ve got my first autocross on 10/4 and I think I’ll wait to see how hard that bug bites me before I commit to dedicated wheels...

 

[MasterC17]

Thanks for the feedback! I’m not worried about range, fortunately. I’ve got my first autocross on 10/4 and I think I’ll wait to see how hard that bug bites me before I commit to dedicated wheels...

The PS4S should serve you fairly well for AutoX, even in the stock 235. If you decide to do this often I would recommend coilovers and camber arms. Otherwise, the tires will wear very quickly. MPP has great solutions.