Tyre temperatures

Grabarz · Mar 12, 2017

Hello There once again I'm trying to rebalance my version of Nissan ...

Ive managed to add new tyres, rebalance brakes, added horse power, etc.

Since i knew that Z-tune is running on 265/25R19 tyres i replaced them with Mclaren P1 front tyres

now my car has proper traction and somehow good cornering however i can't control tyre temperatures
I'm starting with 32 psi pressure and ending with 39-40 psi after just one lap at nordschleife :/

WIDTH=0.265
RADIUS=0.3208
RIM_RADIUS=0.254
ANGULAR_INERTIA=1.70
DAMP=600
RATE=323960
DY0=1.6426
DY1=-0.044
DX0=1.5866
DX1=-0.044
WEAR_CURVE=__cm_tyre_wearcurve_rear_4.lut
SPEED_SENSITIVITY=0.003161
RELAXATION_LENGTH=0.07471
ROLLING_RESISTANCE_0=12
ROLLING_RESISTANCE_1=0.00050
ROLLING_RESISTANCE_SLIP=5245
FLEX=0.000448
CAMBER_GAIN=0.097
DCAMBER_0=1.5
DCAMBER_1=-13
FRICTION_LIMIT_ANGLE=7.1
XMU=0.22
PRESSURE_STATIC=23
PRESSURE_SPRING_GAIN=1980
PRESSURE_FLEX_GAIN=0.4
PRESSURE_RR_GAIN=0.55
PRESSURE_D_GAIN=0.0045
PRESSURE_IDEAL=32
FZ0=3468
LS_EXPY=0.7461
LS_EXPX=0.8089
DX_REF=1.51
DY_REF=1.48
FLEX_GAIN=0.041
FALLOFF_LEVEL=0.88
FALLOFF_SPEED=2
CX_MULT=1.08
RADIUS_ANGULAR_K=0.02
BRAKE_DX_MOD=0
__CM_SOURCE_ID=ferrari_laferrari

[THERMAL_FRONT_4]
SURFACE_TRANSFER=0.0180
PATCH_TRANSFER=0.00024
CORE_TRANSFER=0.00024
INTERNAL_CORE_TRANSFER=0.0034
FRICTION_K=0.05779
ROLLING_K=0.21
PERFORMANCE_CURVE=__cm_tyre_perfcurve_front_4.lut
GRAIN_GAMMA=1
GRAIN_GAIN=0.5
BLISTER_GAMMA=1
BLISTER_GAIN=0.5
COOL_FACTOR=1.82
SURFACE_ROLLING_K=0.96492

Can someone explain to me how to decrease pressure gain ? since tyre temperature seems to be normal ...

Qazdar Karim · Mar 12, 2017

CORE_TRANSFER=0.00024

try a value around 0.004

Grabarz · Mar 12, 2017

Qazdar Karim said:
CORE_TRANSFER=0.00024

try a value around 0.004

wait You are suggesting that tyre pressure gain lies into tyre temperature section ?

Grabarz · Mar 12, 2017

ok so i tried
i changed value in CORE_TRANSFER under THERMAL_FRONT/REAR category from 0.00024 to 0.004 well i can't see much difference in tyre pressure

it's still rising like crazy

Qazdar Karim · Mar 12, 2017

CORE_TRANSFER=0.00024
INTERNAL_CORE_TRANSFER=0.0034

set both to 0 and start from there

you will have constant pressure with 0

Grabarz · Mar 12, 2017

I do not want a godlike tyres

I think my problem lies in the car ...
Nissan has 70:30 weight distribution and weights 1600kg meanwhile McLaren P1 which tyres i used weights max 1250kg and has weight distribution about 50:50 ...
Under braking Front tyres pressure is rising to fast i think ( look the screen above ) - anyway in real life under hard braking tyre pressure is dropping it isn't ?

tomorrow i will start testing hopefully i will find out

Grabarz · Mar 16, 2017

OK after many hours of adjusting, driving, crying for God's help i figured it out ...

i think so

Since Godzilla is heavy front tyres suffer the most under braking - well many people including me could say that, but the truth is Godzilla tyres suffer the most under cornering ... maeby not for everyone but for me it's 100% true. MY front tyres temperatures were rising like crazy on every track every corner since i knew that i tried to readjust tyres temperatures in this category:
[THERMAL_FRONT_4]
SURFACE_TRANSFER=0.0180
PATCH_TRANSFER=0.00024
CORE_TRANSFER=0.00024
INTERNAL_CORE_TRANSFER=0.0034
However it made the tyres so so... they were better but still not even close to what i needed ( +9 psi after 3 mins driving, then about 8 psi after 3 mins driving )

I felt confused, most of my work was for nothing i never wanted to create static tyre pressure. I tried many different cars and, studied their tyres files, and then i realized everything what i was looking for were just under my nose
[THERMAL_FRONT_4]
SURFACE_TRANSFER=0.0180
PATCH_TRANSFER=0.00024
CORE_TRANSFER=0.00024
INTERNAL_CORE_TRANSFER=0.0034
FRICTION_K=0.05779
ROLLING_K=0.21
PERFORMANCE_CURVE=__cm_tyre_perfcurve_front_4.lut
Friction - this bit*ch is guilty of my frustration - many tries later, tyres pressure are about +5/6 psi after 3 laps on Nordschleife all around 8:00 mins
and this is how it looks now:
SURFACE_TRANSFER=0.0180
PATCH_TRANSFER=0.00027
CORE_TRANSFER=0.0012606
INTERNAL_CORE_TRANSFER=0.0034
FRICTION_K=0.02581
ROLLING_K=0.16
PERFORMANCE_CURVE=__cm_tyre_perfcurve_front_4.lut
GRAIN_GAMMA=1
GRAIN_GAIN=0.5
BLISTER_GAMMA=1
BLISTER_GAIN=0.5
COOL_FACTOR=1.85
SURFACE_ROLLING_K=0.96492
Thank You Qazdar Karim for help