How Steeda’s Naturally Aspirated S650 Mustang Ran 9.96 on Pump Gas

Steeda’s S650 Mustang Finally Breaks the NA 9-Second Barrier

Steeda’s latest YouTube video captures a methodical push toward a milestone many thought would require a boost. After earlier track outings were derailed by a cracked throttle-body housing, a leaking brake caliper, and a steering rack configuration that disabled drag mode and line lock, the team pulled the Gen 4 5.0-liter Coyote to investigate a misfire code and re-engineered several supporting systems. Aerospace front brakes replaced the faulty setup, Soler Performance repaired the damaged throttle bodies, and adjustable motor mounts were fitted to resolve hood-clearance interference under an Anderson Composites carbon-fiber hood.

The result at South Georgia Motorsports Park was decisive. Driven to the track and fueled with pump E85, the Silver Bullet 2.0 laid down a 9.96-second pass at 137 mph, backed by a 9.98. That makes it the quickest naturally aspirated Mustang GT on pump gas to date. The car retains its factory-sealed Coyote engine and 10-speed automatic transmission, relying instead on airflow, camshaft upgrades, converter tuning, weight reduction, and chassis optimization.

Steeda’s Longstanding Mustang Pedigree

Nearly three years ago, Steeda partnered with McQueen Racing to continue the legacy of the Bullitt Mustang through limited-production Steve McQueen Edition builds. That program blended heritage cues with modern performance engineering, offering enhanced suspension calibration, braking upgrades, bespoke wheels, and both naturally aspirated and supercharged powertrain options. It was a statement about Steeda’s place in Mustang culture, rooted in history but engineered for contemporary performance.

That collaboration underscored Steeda’s dual role in the ecosystem. The company is not merely a parts supplier; it develops fully realized performance packages validated on road courses and drag strips alike. From suspension geometry to drivetrain durability, Steeda’s approach emphasizes integrated vehicle dynamics.

The Silver Bullet lineage, from its S550 record holder in this previous video to the current S650 iteration, reflects that same engineering-first philosophy rather than opportunistic horsepower chasing.

Naturally Aspirated Still Has Headroom

The 9.96-second pass validates the latent capability of Ford’s Gen 4 Coyote architecture and reinforces that naturally aspirated performance remains viable in the modern era. With ported heads, Cobra Jet intake hardware, GSC cams, a Circle D converter, and comprehensive suspension tuning, Steeda demonstrated that airflow efficiency and drivetrain optimization can rival more aggressive power adders.

Equally significant is how the run was executed: driven to the track, filled with pump E85, and repeated under real-world conditions. That practicality strengthens the claim. For Mustang enthusiasts weighing purity against outright output, Steeda’s Silver Bullet 2.0 proves there is still measurable performance left in the naturally aspirated formula, and the S650’s development curve is far from finished.