Physics HELP - Need some help in Broken Rear Suspension!

[Baricatra]

I'm creating a Custom AE86, I'm learning to model in Blender and Assetto is being my lab.
I took a base model, which was already a mod, and customized it, modeled the aeros, rollcage, custom interior parts.

Anyway, after some modifications, and a little bit of testing, I noticed a strange behavior in the suspension, first by the sounds, but after a closer look, I realized that the rear wheels were clipping on the ground.
It was also tested on different tracks, both mods and base game. It doesn't bother handling so much, but it sure does affect something. Here's a GIF showing what happens (it's in 2x)

So I'm asking for some help here on the forum. I'll also put suspension.ini and car.ini below

Spoiler: Suspension.ini

VERSION=4

[BASIC]
WHEELBASE=2.400 ; Wheelbase distance in meters
CG_LOCATION=0.53 ; Front Weight distribution in percentance

[ARB]
FRONT=43000 ; Front antiroll bar stifness. in Nm
REAR=4200 ; Rear antiroll bar stifness. in Nm

[FRONT]
TYPE=STRUT
BASEY=-0.250 ; Distance of CG from the center of the wheel in meters. Front Wheel Radius+BASEY=front CoG. Actual CG height =(FWR+FBasey)+(RWR+Rbasey))/CG_LOCATION%
TRACK=1.395 ; Track width in meters (from pivot 3D placement of the 3d model of a wheel)
ROD_LENGTH=0.018 ; push rod length in meters. positive raises ride height, negative lowers ride height.
HUB_MASS=36
RIM_OFFSET=0.105 ; masse sospese anteriori
STRUT_CAR=0.177, 0.5262, -0.018
STRUT_TYRE=0.135, -0.1238, 0.01125
WBCAR_BOTTOM_FRONT=0.440, -0.0688, 0.425
WBCAR_BOTTOM_REAR=0.440, -0.0688, 0.00
WBTYRE_BOTTOM=0.135, -0.1238, 0.01125
WBCAR_STEER=0.440, -0.0688, -0.100
WBTYRE_STEER=0.135, -0.1238, -0.100
TOE_OUT=-0.00020 ; Toe-out expressed as the length of the steering arm in meters
STATIC_CAMBER=-1.65 ; Static Camber in degrees. Actual camber relative to suspension geometry and movement, check values in game
SPRING_RATE=85000 ; Wheel rate stifness in Nm. Do not use spring value but calculate wheel rate
PROGRESSIVE_SPRING_RATE=0 ; progressive spring rate in N/m/
BUMP_STOP_RATE=45000 ; bump stop spring rate
BUMPSTOP_UP=0.080 ; meters to upper bumpstop from the 0 design of the suspension
BUMPSTOP_DN=0.085 ; meters to bottom bumpstop from the 0 design of the suspension
PACKER_RANGE=0.160 ; Total suspension movement range, before hitting packers
DAMP_BUMP=4500 ; Damper wheel rate stifness in N sec/m in compression
DAMP_FAST_BUMP=1434
DAMP_FAST_BUMPTHRESHOLD=0.080
DAMP_REBOUND=8000 ; Damper wheel rate stifness in N sec/m in rebound
DAMP_FAST_REBOUND=3089
DAMP_FAST_REBOUNDTHRESHOLD=0.120

[REAR]
TYPE=AXLE
BASEY=-0.255 ; Distance of CG from the center of the wheel in meters. Rear Wheel Radius+BASEY=Rear CoG Actual CG height =(FWR+FBasey)+(RWR+Rbasey))/CG_LOCATION%
TRACK=1.390
ROD_LENGTH=0.025
HUB_MASS=100
RIM_OFFSET=0.02
WBCAR_TOP_FRONT=1.20842, -0.0557, 0.2214
WBCAR_TOP_REAR=1.2680, -0.0594, 0.0308
WBCAR_BOTTOM_FRONT=1.37702, -0.15686, 0.3042
WBCAR_BOTTOM_REAR=1.47702, -0.11686, -0.1154
WBTYRE_TOP=0.06622, 0.1207, -0.0065
WBTYRE_BOTTOM=0.04602, -0.15706, 0.0187
WBCAR_STEER=1.47702, -0.11686, -0.1154
WBTYRE_STEER=0.04602, -0.15706, -0.1154
TOE_OUT=0.00010
STATIC_CAMBER=0
SPRING_RATE=70000
PROGRESSIVE_SPRING_RATE=0
BUMP_STOP_RATE=25000
BUMPSTOP_UP=0.160
BUMPSTOP_DN=0.080
PACKER_RANGE=0.160
DAMP_BUMP=5200
DAMP_FAST_BUMP=800
DAMP_FAST_BUMPTHRESHOLD=0.080
DAMP_REBOUND=6500
DAMP_FAST_REBOUND=1200
DAMP_FAST_REBOUNDTHRESHOLD=0.130

[AXLE]
LINK_COUNT=5
J0_CAR=0.4933,-0.034,0.498 ; car bottom left arm. reference point center of live axle
J0_AXLE=0.5100,-0.095,0.0 ; tyre bottom left arm. reference point center of live axle
J1_CAR=-0.4933,-0.034,0.498 ; car bottom right arm. reference point center of live axle
J1_AXLE=-0.5100,-0.095,0.0 ; tyre bottom right arm. reference point center of live axle
J2_CAR=0.2183,0.100,0.1905 ; car top right arm. reference point center of live axle
J2_AXLE=0.2183,0.040,-0.056 ; tyre top right arm. reference point center of live axle
J3_CAR=-0.2183,0.100,0.1905 ; car top right arm. reference point center of live axle
J3_AXLE=-0.2183,0.040,-0.056 ; tyre top right arm. reference point center of live axle
J4_CAR=-0.435,0.020,-0.110 ; car top right arm. reference point center of live axle
J4_AXLE=0.435,-0.040,-0.110 ; tyre top right arm. reference point center of live axle
TORQUE_REACTION=0.0

[GRAPHICS_OFFSETS]
WHEEL_LF=0.010 ;Left front graphical offset of the wheel positioning in the x axis (width). + is left - is right movement
SUSP_LF=-0.000 ;Left front graphical offset of the suspension positioning in the x axis (width). + is left - is right movement
WHEEL_RF=-0.010 ; Right front as above
SUSP_RF=0.000 ; Right front as above
WHEEL_LR=0.020 ; Left rear as above
SUSP_LR=-0.000 ; Left rear as above
WHEEL_RR=-0.020 ; Right rear as above
SUSP_RR=0.000 ; Right rear as above

[DAMAGE]
MIN_VELOCITY=40 ; MINUMUM VELOCITY TO START TAKING DAMAGE
GAIN=0.0004 ; AMOUNT OF STEER ROD DEFLECTION FOR IMPACT KMH
MAX_DAMAGE=0.05 ; MAXIMUM AMOUNT OF STEER ROD DEFLECTION ALLOWED
DEBUG_LOG=1 ; ACTIVATES DAMAGE DEBUG IN THE LOG

Spoiler: Car.ini

[HEADER]
VERSION=4

[INFO]
SCREEN_NAME=AE86 Sprinter Trueno

[BASIC]
GRAPHICS_OFFSET=0,-0.51,-0.075
GRAPHICS_PITCH_ROTATION=0.5
TOTALMASS=985
INERTIA=1.40,1.30,4.60

[GRAPHICS]
DRIVEREYES=-0.343904,1.04162,-0.280009
ONBOARD_EXPOSURE=21
OUTBOARD_EXPOSURE=30
ON_BOARD_PITCH_ANGLE=-3.754776
BUMPER_CAMERA_POS=0.000000,0.550000,1.740000
BONNET_CAMERA_POS=0.000000,0.530000,0.590000
MIRROR_POSITION=0.0,1.04,-2.0
USE_ANIMATED_SUSPENSIONS=0
VIRTUAL_MIRROR_ENABLED=1
SHAKE_MUL=3
FUEL_LIGHT_MIN_LITERS=7
BONNET_CAMERA_PITCH=-1.145916
BUMPER_CAMERA_PITCH=0.000000

[CONTROLS]
FFMULT=4.527
STEER_ASSIST=1.000
STEER_LOCK=450
STEER_RATIO=-12.50
LINEAR_STEER_ROD_RATIO=0.0020

[FUEL]
CONSUMPTION=0.0035
FUEL=30
MAX_FUEL=50

[FUELTANK]
POSITION=0,-0.15,-1.45

[RIDE]
PICKUP_FRONT_HEIGHT=-0.335
PICKUP_REAR_HEIGHT=-0.325

[PIT_STOP]
TYRE_CHANGE_TIME_SEC=10
FUEL_LITER_TIME_SEC=0.6
BODY_REPAIR_TIME_SEC=20
ENGINE_REPAIR_TIME_SEC=2
SUSP_REPAIR_TIME_SEC=30

 

[Baricatra]

SOLVED, activited the "Double Precision Physics Engine" in CSP

 

[AccAkut]

This wasn't so much an issue with your suspension, but the track you tested on, if that is Shutuko in the screenshot. All solid axle cars twitch around on tracks that big, without the double precision physics switched on.

 

[Baricatra]

This wasn't so much an issue with your suspension, but the track you tested on, if that is Shutuko in the screenshot. All solid axle cars twitch around on tracks that big, without the double precision physics switched on.

Well, like I said, I've tried it on other maps too, even the base game. So apparently it must be a bug in the CSP version

 

[aphidgod]

It's not really a bug, it's just how the vanilla game engine works. It's not meant for large tracks... you will notice it slightly at Nordschleife, but not at any 'normal' circuit.

Very glad Ilja has fixed that for us.

 

[Kyuubeey]

If you look around for a github, you might find my "Arch cars" pack with an AE86 in it. Go ahead and use it for private use if you want.

If you do insist on making your own:

Beware that AC links are very solid and 5 link AXLE will bind up. Convert the UCAs into a single arm to free it up and provide more proper behavior; the kinematics will be maintained.

Do not trust the workshop manual drawings.

I'm not sure any AE86 front bar on the market goes that stiff. Here's what I've done calculationally:

Beware the CG in AC is sprung, not total; and also that AE86s typically have a total CG of 54 - 55% empty, so you'll need something more like 60% in the suspensions.ini to get those wheel loads.