Working on buying some Kosei K1 wheels with the subject specs, thoughts on spacers? Thanks!

 

Does that mean you want or don't want spacers?

In general it is better not to have to run spacers for daily driving.

If you have a thick spacer you will need longer wheel bolts or switch to wheel studs that are long enough for the spacer width plus open ended lug nuts.

Spacers also add a little more weight.

For your 16x7.5" et43 wheels you will be fine with stock suspension. If you lower your MINI you might be OK with 205/50-16 or 195/55-16. Taller than stock tires may risk rubbing.

If you want the flush look you can also use those wheels and add 10-15mm wide spacers but make them hubcentric and add wheel studs that are long enough. A 10mm spacer will make the wheel poke out about 15mm or 0.6" more than stock.

 

Thanks, trying to figure out if I would rub under stock conditions.

 

If you mean stock suspension with stock tires then no rubbing, unless you get a spacer that is too wide. A 10mm spacer would work. Don't forget the longer wheel studs and lug nuts to fit.

 

What's your expert advise on the above, combination with JCW suspension, R53, Wilwood 12.1" on the front, 205/55 R16 Hankook RS3s?

I'd like to find the smallest, lightest, widest rim/tire for track use; 16" rims should fit the Wilwood calipers, but I don't know if the rim will work without rubbing the fender/fender liner...

 

From another thread on big brake kits and wheels-
https://www.northamericanmotoring.co...ated-list.html

Kosei K4R is a newer wheel and not listed under 16" wheels but I think it will fit OK. In 16x7.5" et 43, it weighs 13.6 lbs which is light and only costs $159 each. You can get lighter wheels like Volk TE37V 16x7.5" et43 for about $615 each weighing just under 13 lbs but very strong compared to the K4R.
The TE37V in 16x8" et43 costs about $626 and weighs about 13.6 lbs each.

Is there some reason you are intent on Hankook RS-3 tires in 205/55-16?
You have other Extreme Summer tires in compatible sizes to choose from.


Of note is BF Goodrich g-Force Rival (225/50-16 $143)which is a better tire or


Dunlop Direzza ZII 200 treadwear
205/50-16 $138 each, fits rims 5.5-7.5" wide, 22 lbs, 24.1" tire diameter gives more clearance for suspension and slight lowered gearing.
225/45-16 $138 each, fits rims 7-8.5" wide, perfect for 7.5" rim, 23 lbs, 23.9" tire diameter, more clearance, wider tire, lowered gearing.


Kumho Ecsta XS 180 treadwear
215/45-16 $112 each, fits rims 7-8" wide, 20 lbs, 23.6" tire diameter


Toyo Proxes R1R 140 treadwear
205/45-16 $146 each, fits rims 6.5-7.5" wide, 19 lbs, 23.2" tire diameter one inch less than OEM, very low gearing good for acceleration out of slow corners but less good for higher speeds, low weight and aggressive tread, does wear and can be shaved from 8/32" tread depth to 4-6/32" tread for track use.
225/45-16 $156 each, 23 lbs, 23.9" tire diameter

In closeout at tirerack is-

Bridgestone RE-11 180 treadwear
205/45-16 $154 each, 22 lbs, 23.2" tire diameter
This is replaced by
Bridgestone RE-11A 200 treadwear
205/55-16 $139 each, 23 lbs, 24.9" tire diameter

If you have a bigger budget for tires then you can consider durable R compound tires which can be run on the street to and from events to avoid changing wheels at the track-

Toyo R888 100 treadwear
225/45-16 $205 each, 22 lbs, 23.8" tire diameter, care if using on street and it is wet.


Yokohama Advan A048 60 treadwear
225/45-16 $233 each special order, 2007 production medium hard rubber, 89W rated, 21 lbs, 23.8" tire diam.

Outside of tirerack there are more choices-

Falken Azenis RT-615K 200 treadwear, can be driven on the street like Toyo R888, tends to be noisy
215/45-16 About $150 each, fits rims 7-8" wide, 22 lbs, 23.6" tire diameter

 

Running R1Rs now, I over drive the tires consistently, and after a few laps, they don't stick, no matter what I set pressure for. Most everyone runs Hankook, #2 is BFGs. Durezza was #3. I figured one of these is what I will try next.

Needs to be a street class, 140+ durability.

Kosei seemed to be a reasonable weight/$ ratio.
I didn't want to go after $250+ enkies, because if I broke one...its that much more $$ for the same weight.
I'll be looking for 949s, but since they are only made in the fall, they are a "next year" item.

I'm looking for something with consistent stick when hot.

I was looking at 15" or 16" for lower gearing and the limiting factor was the wilwoods. There aren't alot of tire options for the 16x7.5

Won't the 225 will likely be too wide in 16x7.5, even with the negative camber I'm running?

 

Look at the above tires in 225/45-16, it's a perfect fit for 16x7.5" rims which is what you want, plus it is a little smaller than OEM tire diameter for lowered gearing.

If your track requires street tires rated 140 or higher then pick between-
Direzza ZII
Kumho XS
Toyo R1R
BS RE-11A
Falken RT615K

As far as overdriving goes, do you have access to instructors, if so try to get them to watch you and suggest adjustments, also you can watch them drive your car.

How you drive plays a major role in how you use your tires (and heat them up). Your style of driving will result in correct use of your tires or overuse and overheating. If you are referring to autocross and you get slick tires after a few runs you can use a water spray to cool off your tires between runs which can help. If you are doing lapping sessions on a track you can go out a little slower and let your tires warm up.

Cornering correctly plays a big role in how you use your tires, practice the basics, do most of your braking in a straight line before the initial turn in, minimize trail braking, you might even avoid to do late braking which tends to heat up tires fast. Once you are in mid turn get your steering wheel straightened out before you get on the throttle.

Things to work on in order (Lap after lap):
-Drive the right(best) line
-Get on the throttle as soon as possible coming out of (slow) turns- but be patient, you have to wait until you have finished the turn first
-Be aware of the right corner entry speed, don't overbrake and slow down too much but don't enter a turn too fast (even 1-2 mph too much), this will be different for each car and each corner.
-Carry as much speed as you can in the midturn (this is advanced), by driving the right line and using the right slip angle you will be able to get the most out of your tires and not heat them up as much. Optimal slip angle varies with different tires and often varies with driving style. If you want to see slip angle in action put a GoPro camera just behind the front wheel in the inside of a turn and you can see the wheel is turned but the car is moving in a straighter line.