Drag Tuning — Combined

Sheet 08

RWD

Rear-Wheel Drive — Soft front / stiff rear for weight transfer — Diff Accel is key for launch grip

Standalone →

Tires

Drag

Required — always use for drag

Front PSI: 36 – 42

High = reduces contact, lets front roll freely

Rear PSI: 18 – 22

Low = maximum contact patch & compliance on launch

Front much higher than rear

Promotes weight transfer rearward on launch

Wheelspin off the line → drop rear PSI 1–2 · Slow to 60 → raise front PSI 1–2 for weight transfer

Gearing

Under 400 hp	4.80 – 5.20
400 – 700 hp	4.20 – 4.80
700 – 1000 hp	3.70 – 4.20
1000+ hp	3.20 – 3.70

Wheelspin before finish → raise FD slightly · Hitting limiter before line → lower FD

6-Speed — RWD

Rear-Wheel Drive

Adjust FD to hp range above

Multiplier0.77

Final Drive	4.20
1st	2.80
2nd	2.16
3rd	1.66
4th	1.28
5th	0.99
6th	0.76

Gearing Notes

1st gear	Slightly longer than AWD — manages wheelspin
Top gear	Should hit limiter at end of track
FD rule	Lower than AWD — RWD needs more torque control
Rear aero	Small amount helps traction without hurting top speed
vs AWD	RWD launches harder with high power if tuned right

Alignment

Camber

Front	0° to -0.5°
Rear	0° to -0.5°

Wheelspin at launch → move rear camber closer to 0° for maximum contact patch

Toe

Negative = in · Positive = out

Front	0°
Rear	0° to -0.1°

Car drifting under hard acceleration → add small rear toe-in (-0.1°)

Caster

Angle

5.0° to 6.5°

Car drifting under acceleration → lower caster slightly for lighter steering

Antiroll Bars

Softer front = nose lifts for weight transfer · Stiffer rear = plants on launch

Front	8 – 15
Rear	30 – 45
Note	Soft front = nose rises = weight shifts rearward

Wheelspin at launch → stiffen rear ARB further · Nose won't lift → soften front ARB

Springs

Front	200 – 350 lbs/in
Rear	500 – 700 lbs/in
Ride Height	Raise front slightly, lower rear

Wheelspin at launch → stiffen rear springs or lower rear height · Nose won't lift → soften front springs

Rebound

Controls extension speed · Stiffer front = resists dive · Stiffer rear = resists squat

Front	4.0 – 6.0
Rear	9.0 – 12.0

Nose won't lift at launch → lower front rebound · Rear squatting too much → raise rear rebound

Bump

Controls compression speed · Set bump first · Rebound = bump × 2

Front	2.0 – 4.0
Rear	6.0 – 8.0

Rear won't plant → raise rear bump · Nose rising too violently → raise front bump

Differential Types

StockLow class / saves PI — limited or no tuning available

RaceRWD drag — full accel/decel tuning range

DragDedicated drag diff — maximum lock optimised for launch

DriftRoad drift — high lock bias, sustained slides

OffroadOffroad builds — loose surface compliance

RallyMixed events — road & dirt compromise

Limited accel range → confirm Race or Drag diff · Max wheelspin → use Drag diff for dedicated lock

Aero

Front	Minimum
Rear	Small amount for traction
Note	RWD benefits from small rear wing more than AWD

Wheelspin at launch → add small rear wing · Losing top speed at end of strip → reduce rear wing

Brake

Balance	50 – 55% front
Pressure	100%

Inconsistent braking after run → confirm 100% pressure · No balance adjustment needed on a straight

Differential — RWD

Acceleration	85 – 100%
Deceleration	0 – 5%
Start point	Accel 95% / Decel 0%

Rear wheels not locking together on launch → raise accel to max · Braking instability after run → raise decel slightly

Quick Adjustments

Wheelspin on launchRaise 1st gear / lower rear PSI / add small rear aero
Bogging off the lineLower 1st gear ratio / raise Final Drive

Hitting rev limiter earlyLower Final Drive / add more gear speeds
Front lifting too muchStiffen front ARB slightly / raise front PSI

Poor straight-line stabilityAdd slight rear toe in / stiffen rear ARB
Launch ControlUpgrade to Race Twin Turbo with Anti-Lag under Force Induction

Sheet 09

AWD

All-Wheel Drive — Balanced launch — all four tires planted — Higher FD than RWD — Front diff keeps front rolling

Standalone →

Tires

Drag

Required — always use for drag

Front PSI: 36 – 42

High = reduces contact, lets front roll freely

Rear PSI: 18 – 22

Low = maximum contact patch & compliance on launch

Front much higher than rear

Promotes weight transfer rearward on launch

Wheelspin at launch → drop rear PSI 1–2 · Flat launch → raise front PSI 1–2 for weight transfer

Gearing

Under 400 hp	5.20 – 5.60
400 – 700 hp	4.50 – 5.20
700 – 1000 hp	3.90 – 4.50
1000+ hp	3.40 – 3.90

Wheelspin before finish → raise FD slightly · Hitting limiter before line → lower FD

6-Speed — AWD

All-Wheel Drive

Adjust FD to hp range above

Multiplier0.77

Final Drive	4.50
1st	2.60
2nd	2.00
3rd	1.54
4th	1.19
5th	0.91
6th	0.70

Gearing Notes

1st gear	Short — aggressive launch
Top gear	Should hit limiter at end of track
Ratio spread	Tighter than RWD — AWD hooks earlier
FD rule	Raise if spinning, lower if bogging
vs RWD	AWD typically needs higher FD (more traction to exploit)

Alignment

Camber

Front	0° to -0.5°
Rear	0° to -0.5°

Wheelspin at launch → move all camber closer to 0° for maximum contact patch

Toe

Negative = in · Positive = out

Front	0°
Rear	0° to -0.1°

Car drifting under hard acceleration → add small rear toe-in (-0.1°)

Caster

Angle

5.0° to 6.5°

Car drifting under acceleration → lower caster slightly for lighter steering

Antiroll Bars

Softer front = nose lifts for weight transfer · Stiffer rear = plants on launch

Front	15 – 22
Rear	20 – 30
Note	Balanced for 4WD launch stability

Car tilting at launch → balance ARBs front/rear · Traction loss on launch → confirm ARBs are within range

Springs

Front	300 – 450 lbs/in
Rear	400 – 550 lbs/in
Ride Height	Lower rear, neutral front

Rear squatting under acceleration → stiffen rear springs · Wheelspin on launch → lower rear height

Rebound

Controls extension speed · Stiffer front = resists dive · Stiffer rear = resists squat

Front	4.0 – 6.0
Rear	9.0 – 12.0

Nose won't lift at launch → lower front rebound · Rear squatting too much → raise rear rebound

Bump

Controls compression speed · Set bump first · Rebound = bump × 2

Front	2.0 – 4.0
Rear	6.0 – 8.0

Rear won't plant → raise rear bump · Nose rising too violently → raise front bump

Differential Types

StockLow class / saves PI — limited or no tuning available

RaceAWD drag — full accel/decel tuning range

DragDedicated drag diff — maximum lock optimised for launch

DriftRoad drift — high lock bias, sustained slides

OffroadOffroad builds — loose surface compliance

RallyMixed events — road & dirt compromise

Limited accel range → confirm Race or Drag diff · AWD wheelspin → try Drag diff for maximum launch lock

Aero

Front	Minimum
Rear	Minimum
Note	AWD hooks without rear aero help

Still wheelspin despite AWD → add small rear wing only · Losing top speed → confirm aero is at minimum

Brake

Balance	50 – 55% front
Pressure	100%

Inconsistent braking after run → confirm 100% pressure · No balance adjustment needed on a straight

Differential — AWD

Front

Acceleration	15 – 25%
Deceleration	0 – 5%

Rear

Acceleration	85 – 100%
Deceleration	0 – 5%

Center

Balance

55 – 65% rear

AWD wheelspin at launch → raise rear accel · Front wheels locking → lower front accel

Quick Adjustments

Wheelspin on launchRaise front diff accel / shorten 1st gear slightly
Bogging off the lineLower 1st gear ratio / raise Final Drive

Hitting rev limiter earlyLower Final Drive / add more gear speeds
Not reaching top speedRaise Final Drive / lengthen top gear

Poor straight-line stabilityAdd slight rear toe in / stiffen rear ARB
Launch ControlUpgrade to Race Twin Turbo with Anti-Lag under Force Induction

Made by Caspeyy

Last updated: May 25, 2026

Drag — Combined