I changed out my stock 16" run flat tires and wheels for 17"(Now on Second Set). First set was "Hankook Ventus V12 evo K110" which did not last as long as I would have liked. Changed to Komho 205/45R 17 Ecsta 4X XL. Since the recommeded listed on my door for Winston (2008 MCS) is 33 psi and manual show for 17" to be 38psi up to 100mph (41psi up to 160mph) I filled to the 38psi. Put them to the test on the Dragon for MOTD yesterday. The gripped great with good control, but felt a little mushy. Like there was some "roll" to the outside of the tires in the turns. Not a good feeling.
I do have ALTA rear stabilizer bar set to middle setting.
Any suggestions to correct this?
Thanks in advance for input.
Great event by the way at MINI's On The Dragon in it's 10th year!

 

I am using 39PSI on my Hankook Ventus V12 17" tires for street use and they are much improved. Not sure about the Kuhmo but you might have to experiment a little more.

 

I run 40-41 psi in my NON Runflat tires. After a lot of testing and conversations with an tire and alignment specialist 40-41 seems to be the best place to be with the stock suspension setups.

Thing is the side wall of the NON Runflat is softer and as such will bounce or roll easier than that of a runflat. And with that it changes the way the suspension works as well.

The higher pressure has also eliminated the scalloping on my rear tires. The tread wear is also very even across the tires in all 4 corners even with the stock camber in the rear.

Just got back from the Dragon myself. This was my 4th time being down there and what a great time it has always been.

 

I will try 40-41 PSI later this week as well. The Hankook's are a little soft on the sidewall unfortunately.

 

I think I will bump the psi up tp 40psi and test it over the next week on some twisters.
Should I consider going to a stiffer setting on my ALTA 19" rear sway bar?