[mcbat8]

Car turns in well under trail braking but will have mild understeer in mid corner for long sweeper. Any suggestion what mod to help dial out the understeer?

video example:
https://youtu.be/o8z1c_OktuU?t=644

2022 SS 1LE
Mods:
stock powertrain and weight
Apex - VS-5RS 19x11 and 19x12 with used ZL1 1LE tires (2018 vintage)
Vorshlag- Front camber plate. -3.3f and -2.2r camber. 0 front toe, +0.1 total rear toe.
SPL - Rear Upper Arms and Rear Toe Links
Carbotech XP20 front pads and oem ZL1 rear pads
Endless RF-650 brake fluid

[Christian1LE]

I think the car will always have some understeer if you're asking it to do more than it can or you're not allowing it to rotate enough before getting on the power. You have some options

Run a square setup

Turn all TC and stability control off to help turn the car with the pedals

Start adding proper aero to the front

Stiffen the rear even more.

[VaporPressure]

Are the tires ok? I drive a zle but so far the only time I have had bad mid-corner understeer is when the inner shoulders were cording (or when I get on the gas too early, but that doesn't seem to be the case in your example). I run -3.0 camber so it seems like you have plenty of camber. You could stiffen the rear bar (is it adjustable on SS1LE?). Elsewhere in your lap it seems like occasionally you load up the steering into some of the tighter turns a little aggressively...maybe this is contributing to tires getting overheated/high pressures toward the later parts of the session? But if tires are in good shape and you're having issues even in the beginning of the session, I don't think I have a good answer for you. Nice driving!

[khcoaching]

Anytime you add throttle and add/maintain steering wheel angle, you are setting yourself up for understeer. IMO, your overall entry speed could be improved by using the brakes longer into many of the corners, which will help point the car and accelerate being able to to take away steering wheel angle. Overall lines are pretty good, other than focusing on having the car pointed for the exit.

Ken

[Briland_1LE]

Seems like some corners you were fighting understeer some you were fighting oversteer. I don't think theres an obvious fix other than any corners your having understeer in experiment with a slightly different line or transition etc.

[mcbat8]

Originally Posted by Christian1LE

I think the car will always have some understeer if you're asking it to do more than it can or you're not allowing it to rotate enough before getting on the power. You have some options

Run a square setup

Turn all TC and stability control off to help turn the car with the pedals

Start adding proper aero to the front

Stiffen the rear even more.

Is the ZL1 1LE rear swaybar stiffer? I am thinking that's where I can start.
I am using Race mode which I believe have only TC and no stability control.

[mcbat8]

Originally Posted by Briland_1LE

Seems like some corners you were fighting understeer some you were fighting oversteer. I don't think theres an obvious fix other than any corners your having understeer in experiment with a slightly different line or transition etc.

yeah, 2nd track day with the car so still learning. Corner exit oversteer is expected. I mainly want to improve corner entry and mid corner to slightly more oversteer instead of understeer at the limit.

[mcbat8]

Originally Posted by VaporPressure

Are the tires ok? I drive a zle but so far the only time I have had bad mid-corner understeer is when the inner shoulders were cording (or when I get on the gas too early, but that doesn't seem to be the case in your example). I run -3.0 camber so it seems like you have plenty of camber. You could stiffen the rear bar (is it adjustable on SS1LE?). Elsewhere in your lap it seems like occasionally you load up the steering into some of the tighter turns a little aggressively...maybe this is contributing to tires getting overheated/high pressures toward the later parts of the session? But if tires are in good shape and you're having issues even in the beginning of the session, I don't think I have a good answer for you. Nice driving!

You have some good point. Car felt a lot better in the 1st session in the morning but I think as the day went on, the left front tire got punished to a point where it starts to push. I'll take the wheels off and check them.

[mcbat8]

Originally Posted by khcoaching

Anytime you add throttle and add/maintain steering wheel angle, you are setting yourself up for understeer. IMO, your overall entry speed could be improved by using the brakes longer into many of the corners, which will help point the car and accelerate being able to to take away steering wheel angle. Overall lines are pretty good, other than focusing on having the car pointed for the exit.

Ken

Thanks for the input, my previous track car was a 22 BRZ so I am still adjusting going from momentum car to higher HP car. Right it seems like I am scrubbing the front tires a lot more than the rear and that's why I am looking for some setup adjustments.

[mcbat8]

I guess I found the reason why I was understeering lol. Pictured are front tires, right side is passenger and left is driver.

I was surprised to see this since the tires only have 2 track days on them. Although I did buy them used at around 4.5/32. Does this car like to eat front inside?

[WhiteMale]

Toe is out of spec? Have you rechecked it?

[cdb95z28]

Originally Posted by mcbat8

Is the ZL1 1LE rear swaybar stiffer? I am thinking that's where I can start.
I am using Race mode which I believe have only TC and no stability control.

ZL1 1LE rear bar is NOT stiffer than the SS 1LE rear bar.

[DaveC113]

Originally Posted by cdb95z28

ZL1 1LE rear bar is NOT stiffer than the SS 1LE rear bar.

Yup, it's near the same in it's stiffest setting.

[DaveC113]

Originally Posted by khcoaching

Anytime you add throttle and add/maintain steering wheel angle, you are setting yourself up for understeer. IMO, your overall entry speed could be improved by using the brakes longer into many of the corners, which will help point the car and accelerate being able to to take away steering wheel angle. Overall lines are pretty good, other than focusing on having the car pointed for the exit.

Ken

Agreed.