Recently I installed a M7 STB to help protect mushrooming, also for any potential handling benefits.

My car is a 2005 Cooper S with Sport stock suspension. I did change my wheels to Pro Race 1 and non runflats.

My 1st driving impression is that the car understeers more. Is this likely? Or am I just imagining things?

Overall, I notice less rattling and driving over bumps seems to have muted.

your thoughts?

Mikee

 

I can't answer you because I had the STB and RSB installed at the same time. However, if you installed the wheels at the same time, perhaps a rotation/balance/alignment issue may be the result.

 

It is possible that with the different tires you have more grip. I know the front and rear were changed equally but it may affect the rear more than the front due to the lack of negative camber in front. Adding the FSB willd definately make you more solid up front, but the lack of rattling could be due solely to the softer sidewalls of the non runflats.

I put the M7 brace on before I added the RSB and don't recall feeling increased understeer, just a more solid and predictable feel to the whole operation.

 

Coincidentally, I have the exact same combination of items you do:
m7 STB
17" Team Dynamics Pro Race 1 wheels
Non-runflat Kuhmo tires

I did not notice any tendency to understeer more...

 

simple. remove the bar. drive around put it back on drive around. post results.

 

It's not just you, I noticed a tad more under-steer with the front strut tower bar. 19mm rear bar brought it closer to neutral.

dan

 

I didn't see that after I installed the M7 brace. The handling dynamics appeared to remain the same.

I installed an H-Sport 19mm rear bar & that made everything feel very nice.

 

I did it backwards from you. I first changed the rear sway bar to a hollowed 21mm and noticed significant oversteer. The week after I installed the M7 struts brace, and the entire car turned neutral all the way = a plessure to drive and the most predictable handling.