Drive to Track Wheel/Tire setup

[86Zed]

Currently have about 10 track days under my belt in the M Coupe. All have been on Michelin PS3/4 in a 18x9F and 18x10R (245/35, 275/25) configuration.

Front wheels are bent up (again) where it is noticeable over 80mph. Thinking about getting a dedicated track setup in 18x9 square - worth it or should I stick with staggered? I was thinking Toyo R888 or Bridgestone RE71R for tires.

Appreciate the help!

[Azeka1]

Originally Posted by 86Zed

Currently have about 10 track days under my belt in the M Coupe. All have been on Michelin PS3/4 in a 18x9F and 18x10R (245/35, 275/25) configuration.

Front wheels are bent up (again) where it is noticeable over 80mph. Thinking about getting a dedicated track setup in 18x9 square - worth it or should I stick with staggered? I was thinking Toyo R888 or Bridgestone RE71R for tires.

Appreciate the help!

Go with a square 18X9.5 et35 setup from Apex or Bimmerworld with 265/35/18 200TW tires. You can throw a 12mm spacer on the rear to help make them flush. 265/35 in any R-Comp is an easy fit as long as you dont have KW Clubsports. 275 is certainly possible but not ideal for a street/track car.

Square will make the car more neutral. You'll also be able to maximize tire life by rotating.

I ran R888Rs a couple times and would not use them again since they aren't really any faster or consistent than the 200TW options. They heat-cycle out pretty quick and are not good in the rain once used for a weekend. Since you cannot carry spares, this is really important.

I have found that RE71-R, BFG Rivals or even the Federal RS-RR and other 200TW 'Street Tires' are nearly as good when new but much better once used for a couple sessions. Not to mention they last far longer and will safely get you home in the event of a downpour.

As a side note, you can get away with running 17X9.5 wheels. If you do that, not only will you save on wheels/tires but it also opens up some NT01 options which are a better than R888R. Although I would still recommend a 200TW at your level in either case.

Hope this helps!

[Mgineer]

Completely agree with Azeka but figured I'd add my setup to the mix. I'm mainly an autocrosser and run 285/30/18 square RE71-Rs on 18x10 et25 Apex SM10s. It required fender rolling at all four corners and a mild pull up front but it's definitely worth the performance increase and looks great. No spacers, running TC Kline coilovers which have no helper spring. The transition from my old 245/275 staggered setup to square was a night and day difference and probably the best thing I've done to the car.

[86Zed]

Originally Posted by Azeka1

265/35 in any R-Comp is an easy fit as long as you dont have KW Clubsports!

I am running KW Clubsports, is that going to knock me out of 9.5" square or just the meatier tire sizes? I agree, the RE71 or similar feels like the better option at my level

[Azeka1]

Originally Posted by 86Zed

I am running KW Clubsports, is that going to knock me out of 9.5" square or just the meatier tire sizes? I agree, the RE71 or similar feels like the better option at my level

You should be okay but maybe just call Apex to confirm before ordering. Their fitment guide has some more info. https://support.apexraceparts.com/hc/en-us/articles/360003718253-E85-86-Z4M-Wheel-Tire-Fitment-Guide

[The HACK]

Originally Posted by 86Zed

I am running KW Clubsports, is that going to knock me out of 9.5" square or just the meatier tire sizes? I agree, the RE71 or similar feels like the better option at my level

No. You just need to remove the helper springs to move the perch up a few inches.

The helper spring and perch basically prevents the spring from going full droop and unseating itself, but at my current ride height I’ve gotten the whole front end off the ground and have had no issues with strut travel nor spring droop. Maybe if I’m dropped another 1.5”, but at that point the car would no longer be drivable.

That’s KW Club Sport without the front helper and perch, on Apex PS-7 ET 43 18”x9.5” running Maxxis RC-1 R-comp, 275/35/18 tires and a 15mm spacer* to come to an effective offset of 28. -3 degrees camber. You need the camber and less than 30mm offset to fit, otherwise it interferes with the inner barrel/tire.

* I run ET 43 with a 15mm spacer because these wheels were on CLEARANCE at Apex. Let’s just say I got a whole set of squared up, 18”x9.5” wheels that are lighter than the stock by 5 lbs ea, plus spacers, plus new studs, for less than $1,000.

[86Zed]

Originally Posted by The HACK

No. You just need to remove the helper springs to move the perch up a few inches.

Good to know! Clearance, if only by the slightest margin. I too have been on the lookout for a bargain deal - tires, wheels, balancing, it all adds up.

I will give Apex a holler as well to see their thoughts. Still snowing here, not in a rush.

[TAL2GK]

This is helpful information. I’m slowly moving my Z4M coupe to more of a dedicated track car and just bought a Trailex enclosed so can bring it and spares. Would your recommendations still apply if you weren’t worried about street use? The plan is a spare set of track-only dry tires and to keep the current set for street use and rainy weather at DEs.

[3002 tii]

Just keep in mind R-comps will pick up way more shit off the ground so not only do you risk a puncture, but it'll be more expensive to replace that than a street tire. Also they obviously won't handle damp conditions well, driving back 4 hours from Watkins during a rain storm is an experience I won't ever forget lol.

I've actually asked friends going to same event if they'd be willing to bring my track tires (fortunately know folks with trailers). Else I'd stick to aggressive 200TW tire that can handle both street/track duty =)

[F360C]

Originally Posted by TAL2GK

This is helpful information. I’m slowly moving my Z4M coupe to more of a dedicated track car and just bought a Trailex enclosed so can bring it and spares. Would your recommendations still apply if you weren’t worried about street use? The plan is a spare set of track-only dry tires and to keep the current set for street use and rainy weather at DEs.

I agree with Azeka1 on this one... I dont see a HUGE difference in grip between the current crop of 200tw tires compared to the R888R but they the 200tw tires do last A LOT longer. Therefore my drive to the track and back tire is one of these. So far I have run the RE71R, Direzza's and the BFG Rival.

If I wasn't worried about street use just go straight to a full slick tire (Hoosier, yokohama, etc). I have had great luck with the Continental slicks that they run in Grand-Am. From what I am told they are Hooiser R6's with a different side wall and slightly different compound. Careful though because once you go legit race tire and experience the grip its hard to go back...

[TAL2GK]

Pulled the trigger on a set of Apex EC-7R. The recommended square setup includes 265/35-18 rubber, which sadly Nitto doesn’t make that size. Are the RE-71R the right choice here, or would R888R or Cup2 get your vote? I’ll have separate rims for the rain, these would be 90% track.

[Vanne]

cup2's are expensive as are the r888r, for 90% track id be looking for something else. esp considering you can chuck a set ater 3 sessions max. though not sure how youd go in the rain the other 10 percent of the time on the road. its all a trade off.

[86Zed]

Originally Posted by TAL2GK

Pulled the trigger on a set of Apex EC-7R. The recommended square setup includes 265/35-18 rubber, which sadly Nitto doesn’t make that size. Are the RE-71R the right choice here, or would R888R or Cup2 get your vote? I’ll have separate rims for the rain, these would be 90% track.

RE-71R have a solid reputation at the track and won't get your into trouble on the street. I plan to purchase them once my current Michelin PSS wear out.

[TAL2GK]

Ultimately decided on Hankook RS4. Reportedly quite close to RE-71R for dry grip but significantly longer treadwear. I’ll report back after Road Atlanta the first weekend of June.

[TAL2GK]

After two days each at Road Atlanta, Mid-Ohio, and just back from VIR - I can highly recommend the Hankook RS-4s!

They hold up well and after driving one session at Mid-Ohio on my street tires (because it was looking like rain), I can tell you that the Hankooks are really quite amazing.

[lafuerza]

Curipus if there are any insights with the KW3 suspension which has the beehive progressive springs. I imagine it would make a difference on size. Whats the biggest tire up front that would fit without rolling fenders or anything like that.

[CTMP4me]

Originally Posted by lafuerza

Curipus if there are any insights with the KW3 suspension which has the beehive progressive springs. I imagine it would make a difference on size. Whats the biggest tire up front that would fit without rolling fenders or anything like that.

OEM rule is to have front spring perch be above or close to the top of the tire, that's not always possible though if you're running lowered. A 245/35R18 tire should be an easy fit even for more square shouldered tires and stock alignment, 245/40 will rub if it's squared off like Hankook RS4 or runs "wide" like a Trofeo R. In my experience, a Michelin PS4S in 255/35R18 on a 9.5" wide et35 wheel fits with tons of strut and fender clearance, across full range of suspension travel and turn lock (alignment at 3+ degrees of camber and 8+ degrees of caster angle).

[lafuerza]

Thank you.