One of the first things I do with any build is get new wheels and tires with the goal of getting more width and thus more grip. I also want a set of tires that are designed for the track versus the street for better turn-ins and braking. I once again used Apex wheels as I like that they are designed for BMWs and thus don't need spacers. They also fit many big brake kits, are lighter than OEM wheels, and are reasonably priced. They have a BBS sort of look but without the BBS premium price. Here are some pictures of the before and after, but don't mind the large gap between the tire and fender as we have not dropped the car yet.
I went with 18x9.5 ET28 FL-5 wheels in satin black. I wanted to go as wide as possible without rolling the fenders or having to buy or fabricate a wide body kit. The stock wheels have a staggered setup, but after consulting with Edge Motorworks and Apex we decided to go with a square setup. This will give the front a lot more width while also giving the rear some more width. This also has the added advantage of allowing some tire swapping to prolong the life of the tires. I also went with an Apex stud kit to make wheel changes a snap. While many people prefer the bullet nose style of stud kits (mostly I think because they look good and resemble a professional race car) I always go with the hex head style. The reason being is that the hex head is far easier to install and maintain proper torque settings. The exact kit I used was the black 14mm by 75mm hex head which can be found here.
For tires I went with Nitto NT01 275/35ZR18 95W. These are DOT compliant competition tires and thus are much more suitable for the track than the various OEM tire options. The stock tires are 245 in the front and 265 in the rear so with a 275 square setup I am adding considerable width and grip especially to the front where the car needs it the most (in my opinion). I am not planning on adding any more power to the car outside of what I have already done with a Dinan tune, so I feel the 275 should be fine for the rear. Ideally I would have 285 in the front and 305 in the rear but we plan on adding a big brake kit by Sparta Evolution and KW Clubsport coilovers and we were not sure if 285/305 would fit properly without rolling the fenders. Once we have the brakes and suspension done (in April) we can make the necessary measurements to see if 285/305 would fit and if they do we might swap over to that.
I have taken the car out on the track with these wheels and tires and my first impression is positive. I certainly have better turn-in, braking, and grip overall even with a rather stock alignment. Once I get the brakes and suspension on I will have a better idea on how the whole package will perform, but so far I am pleased. Keep in mind you either need to add TPMS sensors to your track wheels and then constantly reset the system when you lower tire pressure or change tires.....or better yet code out TPMS from your car as I mentioned in my "Coding" blog post.
Next up....brakes and suspension come mid-April.