I've done my best to consume all the good information on two related topics; I'm grateful for everyone's contributions there.
here: https://nam3forum.com/forums/forum/m...ng-sway-choice
and here: https://nam3forum.com/forums/forum/m...uspension-mods
I'm creating this post to focus in on track settings for HPDE on streetable tires (aka I drive the car to the track)
Currently, I have Ohlins R+T, the car is corner balanced. I have 18 x 9.5 ET35 Michelin PS4S square setup with camber at - 2.5 front and - 2.2 rear. This handling is grippy and neutral at the speeds I drive on track with a very slight tendency to drift in oversteer exiting turns at full throttle.
I am interested to learn more about Total Roll Stiffness as calcuated in the FCM Ride Harmony tool, because that number changes significantly with the mods I'm contemplating. I have the GC Front Bar on/order, I have 700# TCK rear springs on/order, and I have a CSL rear sway in the garage as an option. I do not intend to test a different spring rate in the front.
Question: how much total roll stiffness can my car with PS4S tires handle? Will overall grip be worse most of the time with a 50% increase? Going from Ohlins with an OE front and rear sway (3,368 lb-ft/deg) to Ohlins with a GC Front (5,318 lb-ft/deg) is a substantial change mathematically. Is it reasonable to think that at some point the front bar stiffness is great enough that it's only beneficial with track tires? Let's assume as an intermediate driver I'm going on track on dry days. Do I need to leave the GC front bar off until I get stickier tires?
Why I'm doing this: the way my car drives right now there is very good traction, but the sway bar bushings and end links need to be replaced. I'm changing to the GC front sway instead of replacing the bushings and sway bar end links with new OEM. I also want to dial out front sway bar preload, reduce weight a bit, and refresh the bushings. Then I realized I was messing with the overall picture more than I though due to the increased stiffness in the aftermarket sway bars.
So the options look like this:
Or this with the GC Front Sway on Soft
here: https://nam3forum.com/forums/forum/m...ng-sway-choice
and here: https://nam3forum.com/forums/forum/m...uspension-mods
I'm creating this post to focus in on track settings for HPDE on streetable tires (aka I drive the car to the track)
Currently, I have Ohlins R+T, the car is corner balanced. I have 18 x 9.5 ET35 Michelin PS4S square setup with camber at - 2.5 front and - 2.2 rear. This handling is grippy and neutral at the speeds I drive on track with a very slight tendency to drift in oversteer exiting turns at full throttle.
I am interested to learn more about Total Roll Stiffness as calcuated in the FCM Ride Harmony tool, because that number changes significantly with the mods I'm contemplating. I have the GC Front Bar on/order, I have 700# TCK rear springs on/order, and I have a CSL rear sway in the garage as an option. I do not intend to test a different spring rate in the front.
Question: how much total roll stiffness can my car with PS4S tires handle? Will overall grip be worse most of the time with a 50% increase? Going from Ohlins with an OE front and rear sway (3,368 lb-ft/deg) to Ohlins with a GC Front (5,318 lb-ft/deg) is a substantial change mathematically. Is it reasonable to think that at some point the front bar stiffness is great enough that it's only beneficial with track tires? Let's assume as an intermediate driver I'm going on track on dry days. Do I need to leave the GC front bar off until I get stickier tires?
Why I'm doing this: the way my car drives right now there is very good traction, but the sway bar bushings and end links need to be replaced. I'm changing to the GC front sway instead of replacing the bushings and sway bar end links with new OEM. I also want to dial out front sway bar preload, reduce weight a bit, and refresh the bushings. Then I realized I was messing with the overall picture more than I though due to the increased stiffness in the aftermarket sway bars.
So the options look like this:
Attached Files