987.2 Cayman - brake bias controlled via PSM?
01-11-2018, 11:40 AM
#1
Nordschleife Master
Thread Starter
987.2 Cayman - brake bias controlled via PSM?
So I swear I read this somewhere.... but now I can't find it.
Is the braking bias (front/rear) controlled via PSM?
As in - if I disable PSM (ground out the yaw sensor) does that jack up the brake bias?
Is the braking bias (front/rear) controlled via PSM?
As in - if I disable PSM (ground out the yaw sensor) does that jack up the brake bias?
01-11-2018, 04:09 PM
#3
AutoX
Join Date: Nov 2017
Location: West Chester, PA
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Yes the brake bias is adjusted with PSM. However I've seen plenty of people run on the track with the yaw sensor disabled and they either don't have issues or manage to drive through it. I'll be doing the same on my .2 this spring for track days as well.
01-12-2018, 12:08 PM
#4
Nordschleife Master
Thread Starter
Ok so I assume it just "locks in" to a particular bias setting then?
I suppose this could explain why some guys change up pads F/R. Most all of the club racers I know who run Caymans have said they run (or have researched to run) a less-aggressive pad compound in the rear. I bought matched sets (before I knew better, apparently) and couldn't say that the few events I participated in really felt like the bias was screwed up. But then again, I was also unable to properly "kill" PSM as I haven't yet installed the kill switch - so I had "PSM OFF" selected but not fully "killed."
Wondering if, then, once you "kill" PSM - if it suddenly locks into a bias setting that becomes sketchy on track unless you manually tone the rear bias down (with pad compound, or other means).
I also found a guy making adapters to let you install Cayenne rotors on a 987... which I like the idea of... but I figure that would also introduce more rear bias as it enlarges the rears much more than it enlarges the fronts. If, by killing PSM, you already get more rear bias.... well.... just trying to think through everything before I commit to any changes.
I suppose this could explain why some guys change up pads F/R. Most all of the club racers I know who run Caymans have said they run (or have researched to run) a less-aggressive pad compound in the rear. I bought matched sets (before I knew better, apparently) and couldn't say that the few events I participated in really felt like the bias was screwed up. But then again, I was also unable to properly "kill" PSM as I haven't yet installed the kill switch - so I had "PSM OFF" selected but not fully "killed."
Wondering if, then, once you "kill" PSM - if it suddenly locks into a bias setting that becomes sketchy on track unless you manually tone the rear bias down (with pad compound, or other means).
I also found a guy making adapters to let you install Cayenne rotors on a 987... which I like the idea of... but I figure that would also introduce more rear bias as it enlarges the rears much more than it enlarges the fronts. If, by killing PSM, you already get more rear bias.... well.... just trying to think through everything before I commit to any changes.
01-12-2018, 05:17 PM
#5
AutoX
Join Date: Nov 2017
Location: West Chester, PA
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
I had that same problem in my BRZ when I disabled the abs/stability control. We ended up going with a less aggressive pad in the rear I suspect the case will be the same for the Cayman but we'll find out this spring.
01-14-2018, 06:34 PM
#7
Instructor
No, PSM does not control front/rear bias. PSM will only apply the brake at whichever corner it believes will help when the car is at/beyond the edge of stability. Turning PSM off does not change the inherent bias of the car. Installing brake components from other models with larger diameters, different caliper piston sizes, etc., will change the bias.