Mazda RX-8 Tuning Guide — Best A-Class Setup

Class Range: B - A | Base Horsepower: 238 | Drivetrain: RWD | Weight: 1,309 kg | Best Class: A

The RX-8 is one of the most underrated cars in FH6. Every time I tell someone "you should try the RX-8," most of them say "that thing's too slow." 238 horsepower, a 1.3-liter rotary — if you don't understand rotary engines, the numbers genuinely don't look impressive. But the Renesis 13B-MSP's 1.3-liter displacement is equivalent to roughly a 2.6-liter reciprocating engine in the rotary world — because of how a rotary works, it fires three power strokes per revolution. So its 1.3 liters delivers the power density of something like a 3.9-liter piston engine.

What makes the RX-8 unique in FH6 isn't the horsepower — it's the perfect 50:50 weight distribution plus a low center of gravity plus the four-door suicide-door layout. The rotary engine is extremely light and sits extremely low — between the axles and right against the ground. This puts the RX-8's overall center of gravity lower than a Honda S2000. 1,309 kg of mass, a low center of gravity, and 50:50 distribution — this car's cornering dynamics are something most A-class front-drivers and RWD cars simply can't touch. Turn-in is laser-precise, and the body stays so flat mid-corner you'd think someone turned gravity off.

The rotary has its problems too. Below 4,000 rpm there's basically no torque — you have to learn to keep it hanging above 5,000 rpm. Rotaries burn oil by nature — in FH6 it's a fun detail but doesn't affect performance. The rotary's upgrade potential in FH6 is limited — you can't just slap on a big turbo like a piston engine. The RX-8's build direction isn't horsepower, it's perfecting the chassis.

Best Tuning Setup by Class

The third row, the 250hp de-tuned build, is the RX-8's final form. Dump all the PI you save into suspension, weight reduction, and wider tires — a 1,220 kg RX-8 with 250hp and an 8.7 handling rating sits at the top of the pyramid in A-class RWD. The second-row 280hp build is the more common upgrade path — squeezing out power through rotary porting and ECU tuning.

Tuning Parameters — Every Setting Explained

Tire Pressure

Front: 28.5 PSI, Rear: 28.0 PSI. Extreme weight reduction plus low horsepower means you can run really low tire pressure. The front/rear weight distribution is a perfect 50:50, so tire load is spread incredibly evenly. Most of the heat the rotary generates at its 9,000 rpm redline exits through the exhaust system, so temperatures around the rear wheels aren't as high as a V8 car. Tire temps usually sit around 90 degrees front and rear.

Final Drive Ratio

Final Drive Ratio: 4.77 (A-Class). The Renesis rotary's character demands an extremely aggressive final drive — keep the revs above 6,000 at all times. Below 5,000 rpm, an RX-8 is an ordinary family sedan. First and second gear are extremely tightly stacked — pull from a standstill all the way to 9,000 rpm and the shift into second drops you right at 6,000. Third and fourth are your core track gears. Shift point at 8,800 rpm.

Alignment

Camber: Front -2.0, Rear -2.0. The advantage of 50:50 weight distribution — front and rear camber can be exactly equal. Toe: Front 0.0, Rear 0.1. Zero front toe pairs with the rotary's high-rpm response. Rear 0.1 toe-in is extremely conservative. Caster: 6.5.

Anti-Roll Bars

Front: 24.0, Rear: 26.0. Light weight plus 50:50 distribution lets you run much softer anti-roll bars than comparable cars. The slightly stiffer rear bar at 26.0 gives the RX-8 a subtle willingness to rotate on turn-in. Keep these numbers for mountain roads; drop both by 2.0 for high-speed circuits.

Springs

Front: 420 lb/in, Rear: 420 lb/in. Identical front and rear spring rates are extremely rare in FH6 — only a 50:50 car can pull it off. Ride height: lower 1.5 inches. The RX-8 sits too high from the factory; dropping 1.5 inches dramatically improves the center of gravity.

Damping

Rebound: Front 7.0, Rear 7.0. Bump: Front 4.5, Rear 4.5. Identical front and rear damping — the sprung mass distribution is just too balanced. 4.5 bump is one of the lowest recommended values in FH6 — because the rotary's torque delivery is so linear.

Aero

The RX-8 has no factory aero. The A-class build doesn't recommend adding a wing — top speed is 260-270 km/h, and at that speed the drag penalty of aero parts far outweighs the downforce benefit. The RX-8's lap-time advantage lives in low and medium-speed corners. If you absolutely must run high-speed circuits, fit the smallest Forza wing and keep downforce under 30%.

Brakes

Balance: 52% Front, Pressure: 95%. A 1.3-ton car only needs 95% pressure. Upgrade order: brake padsbrake discsbrake lines. Carbon-ceramic brakes are overkill for the RX-8.

Differential

Accel Lock: 50%, Decel Lock: 25%. The rotary's torque curve is extremely linear — you don't need high lock percentages. Decel lock at 25% keeps the rear light and lively on turn-in — the RX-8's strength is its turn-in steering response.

Best Race Types

Technical circuits — the RX-8's god-tier domain. Hairpins, consecutive S-bends, low-to-medium speed transitions — in these places the 50:50 balance, the low center of gravity, and the rotary's instant response let the RX-8 corner as fast as cars from higher classes. Mountain roads — another home turf; the way the rotary carves up a mountain pass is unlike any piston engine. Road racing — bumpy surfaces are its weakness. Rain — the 50:50 balance makes slides more predictable. Drifting — usable, but the rotary's low torque makes holding big-angle drifts harder.

Tuning Share Codes

The RX-8 tuning community is one of the most passionate niche communities in FH6 — rotary fans study this car down to every rotor's apex seal. Share your A-class setup — especially lap data from the 250hp ultra-light build. The rotary never dies.

Common Tuning Mistakes

Blaming the engine for the lack of low-end torque. The truth is your gearing is too tall — a rotary needs to stay above 6,000 rpm. That's your job, not the engine's.

Fitting a big wing and killing your top speed. The RX-8's top speed isn't high to begin with (228 stock, 260-270 when upgraded to A-class). The drag penalty from a big wing drops top speed below 240.

Copying the RX-7's upgrade path. The RX-7 FD is a twin-turbo rotary — a born bruiser. The RX-8 is a naturally aspirated rotary — the tuning direction is completely different.

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