Very good, you found a solution. Nothing about the story was really that far out of line. Many MINIs have 18" with 215/35-18 tires and do very well.
The JCW 18" wheels ride about the same as the stock 17" runflats.

Tire psi is a great place to check first. About 32-33 psi for two people and 37-38 psi cold for up to four people is a general rule of thumb for MINIs.
So you might even try a little less air and see how you do. Also check the wear on your tires and see how much of the outer edges you are wearing.

If you have front camber plates to add to the front negative camber and rear lower adjustable control arms to adjust for more or less rear negative camber then you can use the tires more fully but if you lack these then the alignment shop cannot do much to improve handling even with your suspension upgrades.

Do you have the full alignment settings on a print out? How much front and rear toe and front and rear camber? Those are the crucial values that will determine how your MINI will perform.

Have fun and stay safe.

 

Apparently the very latest '05s have some degree of rear camber adjustment. Still nothing in the front, though.

 

I had a guy borrow my truck one time; when he went to check the tire pressure (good), he used the max rating of 75psi printed on the tire as a fill pressure (bad)

 

Uhm, I really mis-spoke myself above - apologies! I wrote 45 psi cold is high enough for the street. I meant to write 35psi cold, which is where I keep mine all year.

 

I really can't thank you guy enough. I can't believe how much of a difference that made. I could run my old escort with one tire at 50 and the other at 20 and never tell. I called the goodyear dealer who did the alignment and inspection left a strong but polite message about safety and there quality control. I did get the wheels at Wheelmax but goodyear signed off that they checked a bunch of stuff including tire pressure. Never hurts to double check others work. I do always check the torque on lug bolts but a look at the tires to see if they are low isn't something I thought of.

 

Sometimes it is the little things...

400 miles... just let your car take a set first, everything has to mesh.... well, suspension is too late. With the engine i would go to 1350 and then do the pulley -- i did-- and when i put the 17% on with the break-in miles -- holy cow. A Mini tech here recommends all guys break in their cars first before doing the JCW = he has seen theat the cars are faster after they wait till the break-in is over-- i have to agree!!

Good Luck (and slow down for now)

allan

 

Don't forget to reset your flat tire monitor.