ACT 2015 Mitsubishi Lancer XACT Flywheel Streetlite

ACT 600550 is the XACT Streetlite flywheel for the 2008-2015 Mitsubishi Lancer Evolution X with the 2.0L turbo engine and manual gearbox. Our listing names it as a 2015 Lancer, but this is an Evo X part. It weighs 13.1 lb and is the flywheel most Evo X owners choose when they want a lighter, stronger replacement for a worn factory flywheel without giving up street manners. If your Evo X is shuddering on takeoff after a clutch change, or you are building a street car that also sees drag strip passes, this is the version to look at first.

What the Streetlite flywheel does in an Evo X

On the Evo X the flywheel is bolted to the crank behind the 4B11 turbo engine. It carries the 114-tooth ring gear for the starter, provides the friction face for the clutch disc and stores rotating energy. ACT forges the Streetlite in one piece from chromoly steel, CNC machines it, computer balances it and induction-hardens the ring gear, so there is no separate ring gear to loosen and no insert to warp. ACT calls the Streetlite its most durable flywheel and says it is preferred for street or drag racing.

Compared with its lighter sibling, the 600555 Prolite at 10.1 lb, the Streetlite keeps a few extra pounds where they help: smoother pulling away, less tendency to stall in traffic, and only OE to mild gear rattle according to ACT. You still get noticeably quicker engine response than stock. The lightweight vs stock flywheel guide explains the trade.

Symptoms that point to the flywheel

• Clutch chatter when leaving a stop that a new disc did not cure
• Heat checks, blue spots or hairline cracks on the old friction surface
• Slip returning quickly after a clutch replacement on an unmachined flywheel
• Starter grinding or failing to engage cleanly from worn ring gear teeth
• Vibration that grows with RPM after repeated hard launches

How to confirm before you buy

Rule out the hydraulics first: a soft pedal, low fluid or a leaking slave can cause grinding and poor release. To check for slip, pull from low RPM in a high gear at full throttle and watch whether RPM rises faster than road speed. Our slipping diagnosis guide walks through it, and the flare vs slip guide helps separate a clutch problem from other drivetrain issues. On an Evo X the gearbox and transfer case have to come out to reach the flywheel, so most owners make the final call with the old part in their hands: cracks or deep hot spots mean replace it. Other common gearbox faults on these cars are in our Lancer transmission problems guide.

Fitment

ACT lists 600550 for the 2008 and 2010-2013 Lancer Evolution GSR, the 2009 Evolution GSR and RS, the 2014 Evolution and Evolution GSR, and the 2015 Evolution GSR and Final Edition, all with the 2.0L DOHC turbocharged engine. It is not listed for the Evolution MR or for the regular Lancer and Ralliart. ACT specifies a 240 mm (9.4 in) friction surface and 114 teeth, and says any clutch used must match the flywheel step, thickness and ring gear offset. Unsure of your trim or running a swapped gearbox? Send us the year and VIN. More flywheels and hard parts are in our hard parts collection.

Install notes

• Pair it with a 240 mm Evo X clutch. The ACT ME3-HDSS street kit covers the same years and suits most street builds; the ME3-HDG6 six-pad kit is for heavier track use.
• Clean the crank flange and threads and torque the flywheel bolts in a crisscross pattern to the Mitsubishi service manual specification.
• Clean the new friction surface with brake cleaner before the disc goes on.
• Refill the gearbox and transfer case with the gear oil Mitsubishi specifies and bleed the clutch hydraulics.
• When the flywheel needs service later, it can be resurfaced like a stock part. ACT says to remove no more than 0.040 in and keep the correct step.
• Follow the clutch maker's break-in. See our clutch break-in guide.

The 600550 is new, SFI 1.1 certified per ACT, ships from the USA the same business day and carries a 1-year warranty.

Does the 600550 fit a regular Lancer or Ralliart?

No. ACT lists it only for the 2008-2015 Lancer Evolution X with the 2.0L turbo engine: GSR, RS, the 2014 Evolution and the 2015 Final Edition.

Streetlite or Prolite for my Evo X?

The 13.1 lb Streetlite is ACT's most durable flywheel with OE to mild gear rattle, aimed at street and drag use. The 10.1 lb 600555 Prolite revs quicker but ACT says it has reduced drivability.

Does it fit the Evo X MR?

ACT does not list it for the MR. It is for the manual-transmission Evo X trims.

Which clutch should I run with it?

Use a 240 mm single-disc Evo X clutch that matches the flywheel step and offset, such as the ACT ME3-HDSS or ME3-HDG6.

Can it be resurfaced?

Yes. ACT says XACT flywheels resurface like stock ones. Remove no more than 0.040 in and keep the correct step.

• Transmission Slipping Diagnosis Guide
• Shift Flare vs. Slip: How to Tell the Difference
• Automatic vs. Manual Transmission Repair Cost