On Orders of 99+.
100% Money Back on Select Parts
Product images
Product Media
ACT ProLite Flywheel - Subaru STI 2004+
ACT ProLite Flywheel - Subaru STI 2004+
ACT ProLite Flywheel - Subaru STI 2004+
ACT ProLite Flywheel - Subaru STI 2004+
ACT ProLite Flywheel - Subaru STI 2004+

ACT ProLite Flywheel

Subaru STI 2004+

msrp: $538.00

Only 1 left!
You will earn Reward Points with this Purchase.

Features & Product Details

RallySport Direct proudly carries a great selection of quality drivetrain upgrades brought to you by Advanced Clutch Technology.


On this page, you are looking at the ACT ProLite Flywheel. Lightweight flywheels are a great way to remove some of the rotational mass in the engine which produces faster revs along with more power and performance. 



  • Properly distributed for maximum strength, lower inertia, along with good heat tolerance and rigidity
  • Precision machined threads
  • Engineered with the latest CAD and Finite Element Analysis software
  • Hot-forged Chromoly steel
  • CNC machined and dynamically computer balanced for super smooth high RPM reliability
  • Recommended for race applications and can often trigger a CEL
  • Weighs 11.1 lbs
  • Quickens revs
  • Improves power
  • Improves acceleration
  • Product Video


    Brand: ACT
    SFI Approved: Yes
    Weight: 11.1lbs
    Mfgr. Warranty: 1 Year
    Condition: New Product
    Return Policy:
    RallySport Guarantee
    WARNING: Cancer and Reproductive Harm -



    4 Reviews
    4.5 out of 5 Stars
    5 Stars
    4 Stars
    3 Stars
    2 Stars
    1 Stars
    Customer Photos and Videos
    No user media. You can upload a photo or video of your install by posting a review.
    It feels good. 2 years ago
    3out of 5stars
    I want to give it 5 stars but I cannot. With this light weight flywheel my motor keeps throwing an all cylinder misfire every couple days with a brand new iag perfectly healthy long block. I will probably swap it out if I cannot get it to stop putting my check engine light on and putting the car in limp mode. This feels like an amazing all around set up but for daily driving I feel it will not be practical if I cannot make the check engine light to come on every week. If anyone knows of a fix, let me know.
    Was this review helpful?
    Prolite in a 2008 STi 2.5L 7 years ago
    5out of 5stars
    This flywheel is great, installs as easy as the OEM flywheel and noticably encourages faster revs. Boost feels like it comes on faster and it is alot easier to rev match and heel toe. For daily driving this flywheel feels close to standard with only a little more throttle needed to get going from a standstill. Driving up hill the torque loss is barely noticable, however i think this would be different in a 2L. Noise is not notiable at all. I mounted the OEM exedy clutch kit to this flywheel and the driveability is next to stock. Also, shipping was very fast and reliable, even to Australia! Thanks RSD!
    Was this review helpful?
    So far so good 8 years ago
    5out of 5stars
    holding up to 360 hp on mustang dyno in an 08 sti
    Was this review helpful?
    Good buy 10 years ago
    5out of 5stars
    Excellent product
    Was this review helpful?


    • Q: 2019 STI  kfcheung3 years ago

      It was mentioned that it will fit 2015 STI but will this fit 2019 STI?
      • 0 of 0 people found the following answer helpful

        A:  This will fit all USDM STIs

        Tylo R @ RallySport Direct
        Was this answer helpful?
    • Q: balancing the rotating assembly  KennyJ5407 years ago

      If I were to have this flywheel used in conjunction with a lightweight pulley, balanced to the rotating assembly on my build, could it still create CEL issues?
      • 0 of 0 people found the following answer helpful

        A:  From our experience due to the weigh this will trigger a CEL. However if you have everything optimally balanced then you shouldn't have an issue. Keep in mind this is for race applications.

        Trevor C. @ RallySport Direct 7 years ago  
        Was this answer helpful?
    • Q: Fitment.  05 STi7 years ago

      Will this fit if i have a Stage 1 Exedy clutch? I'm sure it does, but just making sure. I have an 05 STi.
    • Q: CEL   kylebrown8191137007 years ago

      If I install just this flywheel with no light weight pulley will it throw the code? or will it throw the code only in conjunction with the light weight pulley?
      • 2 of 2 people found the following answer helpful

        A:  It is the combination of the lightweight flywheel and crank pulley that throws a CEL. Using one or the other by themselves should not cause a CEL to appear.

        guest56ad69792a8d256e198b66b5 @
        Was this answer helpful?
    • Q: need help  kat00f767308 years ago

      It will fit with? Clutch Masterd FX400: Subaru WRX Sti 4cyl 2.5L Turbo 6-Speed 2004-2015 (15017-HRC6
      • 0 of 0 people found the following answer helpful

        A:  This will be an OEM replacment. We cannot confirm direct fitment with Clutch Master's products, As we do not stock them. But as long as it is a direct fitment for 2004-2015 STi, there should be no issue.

        Brady R. @ RallySport Direct 8 years ago  
        Was this answer helpful?

    This Part Fits