600521 is a Prolite flywheel from ACT's XACT lineup, the lightest and lowest-inertia flywheel in the range for the sharpest possible throttle response and acceleration. The forged, CNC-machined, and dynamically balanced chromoly construction is heat-treated for strength and uses an induction-hardened ring gear for long service life, though the reduced mass brings mild-to-moderate gear rattle and less street manners than the Streetlite, making it best suited to road racing or rally use. Like all XACT flywheels it can be resurfaced rather than replaced at service time.
WarrantySpecifications:
- Material: chromoly steel, forged and CNC-machined
- Ring gear tooth count: 112
- SFI Rating: SFI 1.1
- Must be used with a matching ACT pressure plate and disc
- Part Number: 600521
Vehicle Applications:
- 2007 Mazda 3 Mazdaspeed
- 2008 Mazda 3 Mazdaspeed
- 2009 Mazda 3 Mazdaspeed
- 2010 Mazda 3 Mazdaspeed
- 2011 Mazda 3 Mazdaspeed
- 2012 Mazda 3 Mazdaspeed
- 2013 Mazda 3 Mazdaspeed
- 2006 Mazda 6 Mazdaspeed
- 2007 Mazda 6 Mazdaspeed
This product can expose you to chemicals including carbon black, glass wool fibers, and silica (in clutch discs), chromium and nickel, which are known to the State of California to cause cancer or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
FAQ
Can this flywheel be paired with an aftermarket clutch?
Yes. It is built to work with quality aftermarket clutches as well as OE-spec units, provided the clutch is matched to the correct step height, ring gear tooth count, and flywheel thickness. If it is part of an ACT clutch kit, the flywheel that kit specifies should be used.
What is a flywheel step, and why does it matter?
The step is the distance between the friction surface and the pressure plate mounting point, and it sets the correct working range for the pressure plate. Depending on the vehicle it can be an up-step, down-step, or flat design, so matching the correct step is critical to proper clutch function.
Can this flywheel be resurfaced?
Yes, it can be resurfaced the same way as a factory flywheel using a flywheel grinder, removing no more than about 0.040 in (1.02 mm) of material while preserving the correct step height.
Is this flywheel suitable for daily street driving?
The Prolite is ACT's lightest, lowest-inertia flywheel and is best suited to road racing or rally use; expect mild-to-moderate gear rattle and reduced everyday street drivability in exchange for the sharpest throttle response.