Kosei K1 Fitment Question (E36, 17x8.5)

[Mr. Maboomba]

I was running a set of ASA AR1 17x9 ET45 wheels all around on my car for the past 18 months. I have rolled fenders all around and stock sport suspension. I was running 15mm spacers up front. My strut hats were stock (did not swap them for increased camber).

With Toyo T1S 255/40/17 tires all around, they rubbed at 80% turns up front and with several passengers or at 75% suspension compression over bumps in the back. With Pirelli PZero Rosso 245/40/17 tires all around, they rubbed at full lock turns at very slow speeds (3-point turning) in the front only.

I now have a set of Kosei K1 Racing 17x8.5 ET40 wheels all around on the car. I'm running Pirelli PZero Rosso 245/40/17 tires. I still have the 15mm spacers in the front.

The wheels are sticking out in the front more than they used to; enough that they are rubbing on the front fender lip. What is the appropriate size spacer for these wheels? Can I run them without a spacer? I'd like to avoid the $100 cost of new spacers if possible...

Could I just swap the strut hats (will give me about -3* camber) to tilt the wheel inward to clear the fender? One caveat is that the Koseis are going to be track wheels; I will soon be running Velocity Motoring BMW CSL Replica 18x8.5 ET40 wheels with Pirelli PZero Nero M+S 235/40/18 tires as my daily drivers. I would only swap the hats if it wouldn't cause problems with the daily wheels since swapping strut hats and getting an alignment isn't something I want to do all the time.

Cliff's Notes
1. What spacer do I need for Kosei K1 17x8.5 ET40 wheels with 245/40/17 tires?
2. What spacer do I need for BMW CSL Replica 18x85 ET40 wheels with 235/40/18 tires?

[POS VETT]

I'm not a BMW specialist by any measure, but my rough estimate says that you may want to try the fronts w/o spacers. I have seen a picture of the clearance between the rim/tire and the strut rear for LTW (17x8.5, 41mm offset) up front with 245/40/17 Kumho ECSTA MX. There is a very small clearance, maybe in the neighborhood of 3-4 mm. Small, but there is clearance.

Now there should be even smaller to no clearance with 40mm offset and 245/40/17. If I were you, I would try to fit the fronts without any spacers or if there is no clearance (due to variance of tire section width within the same size), try 5 mm spacers. I would try to fit the fronts w/o spacers if you can, trying to stay as close as possible to the stock offset will keep your scrub radius to minimum.

I will be running the same size Kosei K1R soon on my 1998 M3/4 with 235/40/17 Falken Azenis RT-615 on all 4. This size tire actually has the same section width as the 245/40/17 Sumitomo HTR+ that came with the car (from the previous owner). I'm done trying to fit the largest tires possible under my cars, there is too much mucking around involved. Trying to house 315/30/18 Pirelli PZero Corsa on all 4 corners of my Z06 was quite an experience. I'm glad I found out that they fit, but I'm not going to go through it again.

BTW, here are my stabs in the dark on your two questions:

1. None or 5 mm.
2. 235/45/17 won't fit on 18x8.5, but you may want to try 245/35/18. That will keep the overall diameter very close to stock and proper width. As far as spacer size, see #1.

[Mr. Maboomba]

BTW, here are my stabs in the dark on your two questions:

1. None or 5 mm.
2. 235/45/17 won't fit on 18x8.5, but you may want to try 245/35/18. That will keep the overall diameter very close to stock and proper width. As far as spacer size, see #1.

Thanks for the comprehensive reply. Ask an intelligent question, get an intelligent answer, I guess. Oh, and thanks for making me look dumb on question 2 :stickoutt. It was a typo... the tires are 235/45/18... thinnest sidewall I could get in an all-season :shifty

[POS VETT]

Well, 235/45/18 is very tall compared to your stock OD. If I'm not mistaken, the 235/45/17 is already in the 25.5ish inch OD. 235/45/18 will be way above 26 inch OD.

[Mr. Maboomba]

My mistake again. They're actually 235/40/18, which are 25.4" OD, which is 2.2% slower than stock. As close as I could get, as I said.

[thumper525]

I run kosei 17x8.5 with 245/40 RA1s with no spacers. Stock suspension - no rubbing.

[Theodore]

FWIW, I run 17x8.5 contours all the way around. 245/40-17 MX's on em with no spacers and no rubbing at all on stock M3 suspension.

[Jim@tirerack]

You really should not need to run a spacer. At the most maybe a 5mm spacer. We do have them available with the longer lug bolts.
If I can help let me know.

[vjlax18]

Jack the car up, put the wheel on with no spacer. Check the clearance to the strut from the tire/wheel. Give it a good 1/4 inch clearance.

The 235/40/18 is too tall if you're rubbing with a 245/40/17.

[POS VETT]

Okay.

I got my K1R installed two days ago by Discount Tire (gotta love my DT guy), keep in mind this is an M3 with stock suspension. The K1R is 17x8.5, 40mm offset with 235/40/17 Falken Azenis RT-615 (which I came to find out that it is about as wide as some others' 245/40/17, maybe this is an oversized 235/40/17). The fronts sit close to the strut housing but I'm not worried. Push comes to shove, I'll get toddman's 3mm spacers for the front. That will solve the problem in the front.

The rear is hard to say. I haven't really got a chance to load the car up and cycle the suspension. Maybe when I'm doing to the shocks/springs, I'll put the rear wheels on (w/o springs/shocks) and cycle them to see if there is any interference. But, from the looks of things right now, I doubt that it would rub.

The tires sit very nicely on the wheels. This particular 235/40/17 works very well with an 8.5"-wide wheel. I would recommend this kind of combination of wheel/tire widths. Not to mention that the wheels are considered very lightweight at 16.8 lbs (TR's claim). Another advantage: now that's all four are the same size, I can rotate them (I did the same thing on the Z06, now it rides on 315/30/18 PZero Corsas on all 4). The best improvement: understeer should be reduced significantly, just like the Z06.

Looks are subjective, but the exposed/somewhat protruding 6 spokes are growing on me. Sure they don't look as pretty as the OEM LTWs (with machined lips !) they replaced, but these give the car a new character, more like muscular stance instead of that of a pretty boy.

Enough rambling. Use this review accordingly :)