Dodge Challenger SRT Demon Tuning Guide — Best Setup for FH6

Class Range: A - S2 | Base HP: 840 | Drivetrain: RWD | Weight: 1,930 kg | Best Class: S1 (Drag)

The Dodge Challenger SRT Demon is the spiritual opposite of every European hypercar. Where the Jesko is a surgical instrument, the Demon is a sledgehammer. 840 horsepower from a supercharged 6.2-liter Hemi V8 that sounds like it's actively trying to tear itself apart. This is the car you buy when you want to do one thing — go fast in a straight line — with maximum theater.

And here's the thing: it's terrible at everything except drag racing. The handling is atrocious, the brakes are overwhelmed by the weight, and the transmission feels like a tractor. But on a drag strip, the Demon is the king of S1 class. Tuning the Demon is all about the launch — if the car doesn't hook up in the first 60 feet, you've already lost.

Best Tuning Setups by Class

S1 (900) — Drag Strip King

Tires: 20/30 PSI
Gearing: Drag-focused, 4.10 final
Camber: -0.5°/-0.2°
ARB: 18/12
Springs: Front 650 / Rear 250
Ride Height: Front min, rear +5
Aero: Min both
Diff Accel: 100%/0%

The ultimate S1 drag build. Soft rear springs for maximum squat, full diff lock, tall rear ride height creates wedge for weight transfer.

S1 (900) — Roll Racing

Tires: 24/31 PSI
Gearing: Speed final, 3.60
Camber: -0.8°/-0.4°
ARB: 20/15
Springs: Front 600 / Rear 350
Ride Height: Front min, rear +2
Aero: Min both
Diff Accel: 95%/5%

For highway roll racing. Slightly firmer rear to prevent excessive squat at 300+ km/h.

Key Tuning Parameters

Engine & Power

The supercharged Hemi provides instant boost — no lag to manage — but the supercharger consumes significant engine power just to turn the blower. Upgrading to a race supercharger adds boost pressure but also increases parasitic loss. I prefer keeping the stock supercharger and spending PI on weight reduction and tires. The engine responds extremely well to camshaft upgrades — the stock cam leaves 50-80 hp on the table.

Suspension & Handling

Drag suspension is backwards from circuit suspension. You want rear springs as soft as possible without bottoming out — 250 lb/in is my starting point. Front springs should be stiff (600-650) to prevent the nose from lifting. Rear ride height should be 3-5 clicks higher than front for permanent forward rake. Bump damping: extremely soft rear (2-3), stiff front (7-8).

Gearing Strategy

2nd gear is the money gear — it should take you from ~50 km/h to ~120 km/h, covering the bulk of the quarter-mile. You should cross the finish line at redline in 4th gear. If you're grabbing 5th before the traps, your final drive is too short.

Common Tuning Mistakes

ProblemFix
Wheelspin through 1st and 2ndLower rear tire pressure to 18 PSI, soften rear springs 50 lb/in, throttle modulation until 3rd gear
Car bogs off the lineShorten 1st gear, increase launch RPM to 2,800, check cold tires
Nose lifts too much under accelerationStiffen front springs 75 lb/in, lower rear ride height 3 clicks