FAST

FACTS

The first and only factory boosted Miata. The Mazdaspeed is an LS trim Miata featuring a 6spd and an IHI ball bearing turbocharger (factory-developed and installed) producing 8.5 lbs of boost. The compression ratio was only reduced to 9.5:1 (vs 10:1) and the variable valve timing system was removed. Redline was only reduced to 6500 RPM (vs 7000 in base N/A form). Also came equipped with a Denso air-to-air intercooler
Mazda modified the 6spd transmission by shot-peen hardening the gears and changing the 4th gear ratio to a more desirable 1.258 ratio. Other factory mods include heavy duty 25mm driveshafts, heavy duty clutch, performance-tuned exhaust, and a Bosch torque-sensing limited slip diff w/ 4.10 final drive ratio. In addition, the steering rack stroke was shortened from 60.5mm to 53.2mm
The suspension sits 7mm lower and features stiffer springs (215# front, 158# rear), bigger anti-roll bars (23mm up front, 14mm in rear), and Mazdaspeed tuned Bilstein shocks. The 17″ Racing Hart aluminum wheels are 2 lbs lighter than the N/A Miata’s 16″ wheels, and they’re wrapped in wider 205mm tires. The result was a Miata that could pull over 0.98 g in the corners
The factory-installed turbo system is quiet, employing induction resonators to reduce unwanted noise. Car and Driver stated “The turbo itself is virtually transparent — you can’t even hear it with the top up —and it suffers so little lag that the car mostly feels naturally aspirated.”
All the differences between a Mazdaspeed and regular MX5 can be found here in bold

Key Model Year Changes:

The Mazdaspeed Miata was only produced in 2004 and 2005. There were no notable differences between the two
Velocity Red Mica and Titanium Gray Metallic were the only paint colors available in 2004. Lava Orange Mica and Black Mica paint became available in 2005
Only 1,428 Mazdaspeed Miatas were produced in 2005, due to a fire at the assembly plant cutting production short. In comparison, 4,000 MSM’s were produced in 2004

Specs: