Dinan S3 boosts BMW 550i to M5 levels

Dinan introduced the 2013 BMW 550i S3 on Tuesday. The tuner upgrades the already quick sedan to 542 hp, but claims to retain enough refinement to be a daily driver. The upgrade is also factory backed for four years or 50,000 miles by Dinan's nationwide network of service centers.

The stock BMW 550i makes 400 hp, a serviceable amount but nowhere near the M5's 560 hp or even Dinan's 542 hp. The power comes from Dinan's larger intercoolers and turbochargers, high-flow intake and tuned exhaust. Torque grows from 450 lb-ft in the 550i to 587 lb-ft in the Dinan. For reference, the BMW M5 makes a round 500 lb-ft.

The Dinan Stage 5 Performance software digitally connects the new hardware, changing the way the car performs throughout the powerband, according to Dinan. The new computer programming remaps the throttle, improves drivability from idle to wide-open throttle and recalibrates the top-speed governor, bringing terminal velocity to more than 200 mph, according to Dinan.

To keep that power under control, the S3 also gets Dinan-tuned lowering springs, and new programming for the electronic damping control, changing the car from track to tame with the press of a button.

Optional features include lightweight, forged wheels, a limited-slip differential and Brembo slotted brake rotors and calipers. Cosmetic upgrades are also offered for both the interior and exterior.

The whole package is offered on the rear- and all-wheel-drive 550i, as well as the 650i and 750i with either rear- or all-wheel drive.

The 2013 BMW 550i is $62,625 while the full Dinan upgrade costs $38,773, including the visual upgrades. For comparison, the 2013 M5 rolls off the lot for nine grand less, at $92,425.

Full pricing list:

Stage 6 Performance Engine Software $4299

Twin-Turbo Upgrade $5880

Free Flow Exhaust (Rear Mufflers) $3599

High Performance Air-to-Water Intercooler $2699

Carbon Fiber High Flow Air Intake/Strut brace $2599

Total for S3 Engine Tune: $19076

Suspension

Performance Suspension System $499

Shockware $799

Low Compliance Rear Control Arms $799

Front Camber Arms $999

Total for S3 Suspension Tune: $3096

Accessories

Dinan Aluminum Pedal Pad Set $199

Dinan Deck Lid Badge Included

Dinan S3 Serial Numbered Plaque Included

Total for S3 Accessories: $199

Options

Wheels/Tire & Brakes

Front Wheel: HRE 20 x 9” $6400 set

Rear Wheel: HRE 20 x 10”

Front Tire: 275/35-20 Michelin Super Sport $335 ea.

Rear Tire: 295/35-20 Michelin Super Sport $419 ea.

Dinan by Brembo brakes $4895

Driveline

Limited Slip Differential $3599

Exterior/Interior

BMW Performance Carbon Fiber Spoiler $600

BMW Performance Black Grille $140 pair

BMW Front Carbon Splitter $1400

BMW Carbon Mirror Caps $700 pair

Bavsound Stage 1 Audio Upgrade $999

By Jake Lingeman