AX2 modified

[cologne]

I saw that the AX2 car is used for testing tracks in new SVn´s.

The definition of the car is horrible frontmotor and 30 centimeter travel for a race car? -))))

I made some - not scientific - changes and now the car is a little bit better!

# AX2.2
# modified by cologne 20070820 0.2
# modified by cologne 20070820 0.1

drive = RWD

[ steering ]
max-angle = 36.39

[ engine ]
#position = 1.42, 0.0, -0.24
position = -0.50, 0.0, -0.24
mass = 180.0
max-power = 4.66062e5
peak-engine-rpm = 7500.0
rpm-limit = 8500.0
inertia = 0.5
idle = 0.02
start-rpm = 1000
stall-rpm = 350
fuel-consumption = 1e-9
torque-friction = 0.0010
torque-curve-00 = 1000, 450.0
torque-curve-01 = 1500, 475.0
torque-curve-02 = 2000, 500.0
torque-curve-03 = 2500, 525.0
torque-curve-04 = 3000, 555.0
torque-curve-05 = 3500, 575.0
torque-curve-06 = 4000, 605.0
torque-curve-07 = 4500, 625.0
torque-curve-08 = 5000, 655.0
torque-curve-09 = 5500, 675.0
torque-curve-10 = 6000, 705.0
torque-curve-11 = 6500, 725.0
torque-curve-12 = 7500, 749.0
torque-curve-13 = 8000, 729.0
torque-curve-14 = 8500, 709.0


[ clutch ]
sliding = 0.27
radius = 0.15
area = 0.75
#max-pressure = 21079.26
max-pressure = 50000.00

[ transmission ]
gears = 6
gear-ratio-r = -2.8
gear-ratio-1 = 2.70
gear-ratio-2 = 1.99
gear-ratio-3 = 1.40
gear-ratio-4 = 1.14
gear-ratio-5 = 1.00
gear-ratio-6 = 0.90
shift-delay = 0.00

[ differential ]
final-drive = 2.87
anti-slip = 300.0

[ fuel-tank ]
position = -0.26, -0.17, -0.56
capacity = 0.0492
volume = 0.0492
fuel-density = 730.0

[ suspension-front ]
#spring-constant = 72000
spring-constant = 102000
bounce = 10050
#bounce = 7500
#rebound = 10700
rebound = 7000
#travel = 0.30
travel = 0.10
max-compression-velocity = 10.0
camber = -1.33
caster = 0.12
toe = 0.9
#anti-roll = 15000
anti-roll = 11000

[ suspension-rear ]
#spring-constant = 68000
#spring-constant = 98000
spring-constant = 130000
#bounce = 12000
bounce = 7500
rebound = 9992.14
#rebound = 8500
#rebound = 5000
#travel = 0.30
travel = 0.12
max-compression-velocity = 10.0
camber = -0.45
caster = 0.28
toe = 0.0
anti-roll = 7000

[ tire-front ]
radius = 0.325
rolling-resistance = 1.3e-2, 6.5e-6
#rotational-inertia = 10.0
rotational-inertia = 3.0
tread = 0.0
# Lateral force
a0=1.39
a1=-90
a2=1900
a3=2900
a4=7.2
a5=0.024
a6=-0.24
a7=1.0
a8=-0.03
a9=-0.0013
a10=-0.15
a111=-8.5
a112=-0.29
a12=17.8
a13=-2.4
# Longitudinal force
b0=1.95
b1=-85
b2=1950
b3=24.3
b4=390
b5=0.07
b6=0
b7=0.059
b8=-0.024
b9=0.014
b10=0.26
b11=0.0
b12=0.0
# Aligning moment
c0=2.2
c1=-4.1
c2=-4.2
c3=-1.8
c4=-9.1
c5=0.0225
c6=0
c7=0.044
c8=-0.58
c9=0.18
c10=0.043
c11=0.048
c12=-0.0035
c13=-0.18
c14=0.14
c15=-1.029
c16=0.27
c17=-1.1

[ tire-rear ]
radius = 0.340
rolling-resistance = 1.3e-2, 6.5e-6
rotational-inertia = 3.3
tread = 0.0
# Lateral force
a0=1.55
a1=-50
a2=1750
a3=2800
a4=7.0
a5=0.024
a6=-0.24
a7=1.0
a8=-0.03
a9=-0.0013
a10=-0.15
a111=-8.5
a112=-0.29
a12=17.8
a13=-2.4
# Longitudinal force
b0=1.75
b1=-100
b2=2200
b3=23.3
b4=410
b5=0.075
b6=0
b7=0.055
b8=-0.024
b9=0.014
b10=0.26
# Aligning moment
c0=2.2
c1=-4.3
c2=-4.4
c3=-1.9
c4=-9.6
c5=0.0225
c6=0
c7=0.044
c8=-0.58
c9=0.18
c10=0.043
c11=0.048
c12=-0.0035
c13=-0.18
c14=0.14
c15=-1.029
c16=0.27
c17=-1.1

[ brakes-front ]
friction = 1.40
max-pressure = 2.5e6
bias = 0.61
radius = 0.17
#area = 0.015
area = 0.020

[ brakes-rear ]
friction = 1.40
max-pressure = 2.5e6
bias = 0.39
radius = 0.14
area = 0.015
handbrake = 1.0

[ driver ]
#position = 0.35, 0, -0.3
position = 0.05, 0, -0.3
mass = 90.0
view-position = 0.38, 0, 0.18
hood-mounted-view-position = 1.0, 0, 0.2

[ drag ]
position = 0.0, 0.0, 0.2
frontal-area = 2
drag-coefficient = 0.3

[ wing-front ]
position = 1.9, 0.0, 0.60
frontal-area = 0.2
drag-coefficient = 0.0
#surface-area = 0.3
surface-area = 1.5
#lift-coefficient = -0.9
lift-coefficient = -2.0
efficiency = 0.99

[ wing-rear ]
#position = -2.14, 0.0, 0.37
position = -1.80, 0.0, 0.37
frontal-area = 0.05
drag-coefficient = 0.0
#surface-area = 0.5
surface-area = 1.9
lift-coefficient = -3.0
efficiency = 0.99

[ wheel-FR ]
position = 1.46, -0.81, -0.43
roll-height = 0.325
mass = 19
restitution = 0.1

[ suspension-FR ]
position = 1.46, -0.75, -0.07
hinge = 0,0,0

[ wheel-FL ]
position = 1.46, 0.81, -0.43
roll-height = 0.325
mass = 19
restitution = 0.1

[ suspension-FL ]
position = 1.46, 0.75, -0.07
hinge = 0,0,0

[ wheel-RR ]
position = -1.32, -0.81, -0.42
roll-height = 0.340
mass = 19
restitution = 0.1

[ suspension-RR ]
position = -1.32, -0.75, -0.07
hinge = -1.0,0,0

[ wheel-RL ]
position = -1.32, 0.81, -0.42
roll-height = 0.340
mass = 19
restitution = 0.1

[ suspension-RL ]
position = -1.32, 0.75, -0.07
hinge = -1.0,0,0

[ contact-points ]
# used to find the bounds of the car (for collisions)
# also play into the weight distribution and balance
mass = 0.05
position-00 = 2.35, 0.0, -0.6
position-01 = 2.31, 0.48, -0.6
position-02 = 2.31, -0.48, -0.6
position-03 = 2.14, 0.86, -0.6
position-04 = 2.14, -0.86, -0.6
position-05 = 2.0, 0.96, -0.6
position-06 = 2.0, -0.96, -0.6
position-07 = 0.52, 0.97, 0.22
position-08 = 0.52, -0.97, 0.22
position-09 = -1.87, 0.95, -0.6
position-10 = -1.87, -0.95, -0.6
position-11 = -2.29, 0.43, -0.53
position-12 = -2.29, -0.43, -0.53
position-13 = -2.36, 0.30, -0.20
position-14 = -2.36, -0.30, -0.20
position-15 = -2.3, 0.84, 0.56
position-16 = -2.3, -0.84, 0.56

# these are used to calculate the weight distribution and balance
[ particle-00 ]
mass = 25.0
position = -1.35, 0.0, -0.47

[ particle-01 ]
mass = 50.0
position = 0.96, 0.0, -0.47

[ particle-02 ]
#mass = 213.0
mass = 140.0
position = -0.3, 0.5, 0.09

[ particle-03 ]
#mass = 213.0
mass = 140.0
position = -0.3, -0.5, 0.09

[ particle-04 ]
mass = 143.0
position = 1.2, 0.45, -0.13

[ particle-05 ]
mass = 143.0
position = 1.2, -0.45, -0.13

[cotharyus]

Interesting. I'll try it and see what it's like. If it's good, I'll commit it. I don't know if the AX2 has been changed since my last commit on it, but that commit was one step towards making the specs and performance similar to an Audio R8 (LMP1). Which, should of course, have a rear mounted engine configuration.

[cologne]

i compared the AX2 of the latest release and your r1813 build for mac. They are identical.

The release AX2 had similar values as the release F1.
It´s a ground-effect car, now he has enough downforce. The weight is lowered to nearly 1000kg (12xx look to high). I move some masses, but didn´t compute the weight distribution.

The travel much too high - 30cm - makes trouble.

[cologne]

@cotharyus

The definition above has some little changes, to get better balance and better turn in curves. Increased the downforce, because it´s a groundeffect car.

First Lap Nuerburgring 701, 3.Lap Dijon 106.

I also drove in Monaco -?

[cotharyus]

Cologne - very nice. I will commit this as soon as we get privileges sorted back out on the sourceforge svn repository.

[thelusiv]

So did the AX2 get updated in SVN? I haven't played with it in a while.

[cotharyus]

Yes, it did. After watching the ALMS race from Mosport this weekend though, I think we need to tweak this a little more - we're about 12 seconds fast getting around the track, even with a bump that'll turn the car over at Moss Corner if you hit it too fast.

[cologne]

With the AX2.2 definition, published above, fastest of 8 laps 1:08 .
If Moss Corner is the slowest corner, i made only one lap without turn around!

My F1_sl_2.1 version drives 1:02, but it´s the slow setup for Monaco or Laguna Seca.
(all with Gamepad)

...and the ALMS times?

[cotharyus]

Well, I got around in 1:04 - ALMS I was seeing 1:16 a lot.

[cologne]

Well, I got around in 1:04

DualCore? :-)

I made a AX2.3 version with better mass and downforce distribution. The problem is the same as with "my" F1 car: the tyre definition differences between front and rear tyre is insufficient. Moving the masses more to the rear, the car breaks out. Downforce doesn´t help.
i tried 15% higher a0 and b0 parameters for the rear tyre and the car moves backwards! :-(

[cotharyus]

Dual Core? Yea, but it's also a laptop. If you think the performance of the computer makes that much difference, maybe I should try it at work


Yes, you have to be very careful with the pacejka tire definitions, or it will do very strange things. Post the revision of the AX2 and when I get a chance to I'll play with that. Most of the stuff in the tire definitions has to be somehow proportional. If it's not....well, it just doesn't work well.

[cologne]

I made an archive of the complete AX2.3 directory:

http://www.aikx.de/vDrift/AX2.3.zip

I made a table to compute some values in apple pages named:

vDrift_comp_v3_AX2-3.pages (included)

[xTs]

Is it normal that you loose pretty fast the control of the AX2? So much power that you make a donut in second gear with half gas?

[cologne]

May be!

The AX has to much torque and the tyre definition is not sufficient.
At higher speed my AX3 version works pretty good. A problem with the tyres stays sometimes turning fast in curves, the car oversteers and turns around.

Which AX did you drive? The original release, the SVN Version?

[xTs]

The svn version. Well, its a powerful car... maybe its realistic, dont know, just had to ask