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Old 08-06-2019, 01:38 PM   #8233
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

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Quote:
Originally Posted by rst.ack View Post
Is it me not reading right or am I getting conflicting information here? Seems like YungBoba is saying the narrower wheel gives better turn-in response and Norm is saying the opposite. Which one is it, and can you back it up with anything?
Ultimately, steering response is a matter of how quickly/precisely your inputs at the steering wheel become vehicle turning, or yaw. Time is involved here, and stiffer components get to their new-required state more quickly than otherwise identical but softer ones. We're not talking about lots of time here, not even a whole second, but little time lags are something that you can pick up on at least on a near-subliminal level. Think in tens to hundreds of milliseconds terms here.

As for something a little more concrete, I actually have some datalogged comparative data where the only differences in car setup were the wheels & tires. Same stretch of road, similar weather conditions, same make and model tires (MPSS), with the same tread widths (10.2"). One set was mounted on "measuring width" wheels (9.5"), and the other was mounted on "max-recommended width" wheels (11"). There was a small diameter difference, but only about 0.4" (0.2" on sidewall height). The max-width setup turned in a little better, and had a noticeably more stuck-down "feel" at a little over 0.9g than the measuring-width setup had at a little over 0.8g. The "measuring width" setup wasn't bad, just that it felt a little "soft" in comparison to the wider wheel arrangement.

The max-width setup has datalogged beyond 1.3g once fully warmed up in road course track driving.


Norm
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Last edited by Norm Peterson; 08-06-2019 at 01:45 PM.
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