Hello, after raising my R56S LCI for 4+ years, I am building it more for track than street, looks like eventually will be a dedicated track car.

So, I've been using many different wheel/tire setup, now I want to try something unusual(unusual for mini).

My question is, Can I use diffrent diameter on Front and Rear?

Planning 225/45 16 Front and 205/50 16 Rear.

My concern is BMW's advanced ABS/Wheel speed/DSC system, since the rear tire diameter will be bigger by 0.4% compared to the fronts.
(I looked the tires and it is like 5mm of diffrence in terms of tire height, and will be greater once the front tires get the weight when it's on the car)

Will this trigger ABS light? and cause further problems like ABS/DTC mulfunction?

I will try the setup this weekend, not on track, but on road.

I know it's all about finding a balance between aero-suspension-tire setup(and for specific track layout), I really want to try this.

*Not using this car on the road, and I am using stock size 17" 205 square setup when I move the car to track.

 

Interesting thought...., since one generally turns off the ABS/DTC function for track I do not think there should be an issue
I'm going with a 235/40/18 front with Nitto NT01 and the same size in rear but with the less grippy NT05 in the rear.
I might even use a spacer in front depending on the results.

 

What are you trying to achieve in terms of balance? 225 fronts/205 rears suggests you want to reduce understeer. In my experience a fatter rear sway bar gets you most of the way there, and then some negative camber all the way around results in very neutral handling.

Can't tell for sure from your mods list but looks like you have the H-Sport RSB, plus you've got the Ohlins and Vorshlag camber plates (same as me, excellent choice) so you should have everything you need except maybe some adjustable rear control arms for the rear camber.

I'm interested to hear how the staggered sizes work for you, please let us know.

 

Thx for the reply, and I don't turn ABS off and don't know how to do it without ditch the ABS fuse off or go with stand alone ecu.

DSC button will not touch ABS function. I am afraid EBD/CBC feature get confused and kick in when I don't want to(entering 1st corner at 120mph at my local track)

 

Oh, don't mind my sig, it's out dated.(just updated~) I am running OS drivetrain and serious aero mods now, can't drive it on public road for many reasons. (And it's not worth)
I've been setting my car's character from excessive oversteering to mild understeering(and you know the character changes as per speed range, so I don't want to make the character fixed and simple with just RSB setup),
I am on rear camber arms for sure and using assymetrical front camber for specific tracks.

Try to find what kind of setup serious FWD time attack cars are running. (like at Tsukuba time attack EG civics)
They have serious aero downforce for high speed section and running 245(or 255) at front while 205(195 at times) at rear to create tail happy motion at low speed section.