set display mode 800,600,16
sync on
dim rpm(80)
dim gear#(6)
time#=timer()

numgears=6
gear#(1)=2.66
gear#(2)=1.78
gear#(3)=1.30
gear#(4)=1.0
gear#(5)=0.74
gear#(6)=0.5
gear#(7)=0
rpm(10)=400
rpm(15)=420
rpm(20)=435
rpm(25)=450
rpm(30)=460
rpm(35)=470
rpm(40)=480
rpm(45)=480
rpm(50)=460
rpm(55)=440
rpm(60)=400
rpm(65)=0
rpm(70)=0
rpm(75)=0
rpm(80)=0
rpm(85)=0
rpmredline=6000
cof#=0.3
faoc#=1.5
airdensity#=1.29
wheelbase#=2.5
cgheight#=1
cgrpros#=51.5
tfc#=1
mass#=1500
differentialratio#=3.42
transmissionef#=0.7
wheelradius#=0.34

gear=1
cgf#=(wheelbase#/100)*cgrpros#
cgr#=wheelbase#-cgf#
weight#=mass#*9.81
do
gosub controls
gosub engineforcecalculation
gosub slipcalculation
gosub longcalculation
gosub velocitycalculation
gosub weightshift
gosub drift
gosub errors
gosub graphics
sync : cls
loop

controls:
if upkey()=1 and pedal#<100 then inc pedal#,5
if downkey()=1 and pedal#>0 then dec pedal#,5
fbreaking#=0
if controlkey()=1 and velocity#>0 then fbreaking#=4000 : pedal#=0
return

engineforcecalculation:
gosub getmaxtorque
torque#=(maxtorque#/100)*pedal#
drivetorque#=torque#*gear#(gear)*differentialratio#*transmissionef#/wheelradius#
return

slipcalculation:
if velocity#<>0
slipratio#=(wheelrotation#*wheelradius#-velocity#)/velocity#
endif
return

longcalculation:
ftraction#=drivetorque#
cdrag#=0.5*cof#*faoc#*airdensity#
crr#=cdrag#*30
fdrag#=-1*cdrag#*velocity#^2
frr#=-1*crr#*velocity#
flong#=ftraction#+fdrag#+frr#
fslip#=(flong#/100)*abs(slipratio#)
fbreaking#=fbreaking#-fslip#
if fslip#>500 then fslip#=500
flong#=flong#+fslip#-fbreaking#
return

velocitycalculation:
acceleration#=flong#/mass#
dt#=(timer()-time#)/1000 : time#=timer()
velocity#=velocity#+dt#*acceleration#
position#=position#+dt#*velocity# 
return

weightshift:
wf#=(cgr#/wheelbase#)*weight#-(cgheight#/wheelbase#)*mass#*acceleration#
wr#=(cgf#/wheelbase#)*weight#+(cgheight#/wheelbase#)*mass#*acceleration#
return

drift:
driftforce#=tfc#*wr#
return

errors:
if velocity#<0 then velocity#=0 : drivetorque#=0 : flong#=0
return

graphics:
print "Pedal: ";pedal#;"%"
print "Gear: ";gear
print "Gearratio: ";gear#(gear)
print "Rpm: ";rpm#
print "Torque: ";torque#;"/";maxtorque#;"nM"
print "Ftraction: ";ftraction#;"N"
print "Fdrag: ";fdrag#;"N"
print "Frr: ";frr#;"N"
print
print "Flong: ";flong#;"N"
print "Fslip: ";fslip#;"N"
print "Dforce: ";driftforce#;"N"
print "Velocity: ";velocity#;"M/s"
print "               ";velocity#*3.6;"Km/h"
print "Travelled: ";position#;"M"
print
print "Weight: ";weight#;"N"
print "Wf: ";wf#;"N"
print "Wr: ";wr#;"N"

line 400,300+wr#/700,500,300+wf#/700

boxposition#=boxposition#+dt#*velocity#
if boxposition#>600 then boxposition#=0 
box 650,boxposition#,653,boxposition#+5
return

getmaxtorque:
wheelrotation#=velocity#/wheelradius#
crankshaftrotation#=gear#(gear)*differentialratio#*wheelrotation#
rpm#=(crankshaftrotation#*60)/(2*3.142)
if rpm#>rpmredline then rpm#=rpmredline
if rpm#<1000 then rpm#=1000
if rpm#>4800 and gear<numgears then inc gear
if rpm#<3000 and gear>1 then dec gear
r=10
if rpm#>1500 then r=15
if rpm#>2000 then r=20
if rpm#>2500 then r=25
if rpm#>3000 then r=30
if rpm#>3500 then r=35
if rpm#>4000 then r=40
if rpm#>4500 then r=45
if rpm#>5000 then r=50
if rpm#>5500 then r=55
if rpm#>6000 then r=60
if rpm#>6500 then r=65
if rpm#>7000 then r=70
if rpm#>7500 then r=75
if rpm#>8000 then r=80
rpmmiinus#=rpm#-r*100
torquemiinus=rpm(r+5)-rpm(r)
maxtorque#=((rpmmiinus#/500)*torquemiinus)+rpm(r)
return