Skip to product information
1 of 5

ACT 04-20 WRX STI Mod Twin HD Race Kit Sprung Mono-Drive Hub Torque Cap 895ft/lbs Not For Street Use

  • Backed by real installs and tuning experience at FAST of West Chester
Low stock! Only 1 left


Everyday Low Price:

Regular price $2,104.00
Sale price $2,104.00 Regular price $2,598.00 You Save $494.00!
Shipping calculated at checkout.
Payment methods
  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Earn FAST WC Points on this order — redeem on your next purchase

Get it fast — Order now.

I18n Error: Missing interpolation value "end_date" for "Ends on {{ end_date }}"
Up to 19% off
T1R-S05 Mod-Twin 225 HD Sprung Race Kit performs aggressive launches and smoother shifting in high powered AWD’s by combining twice the ceramic friction surfaces with an ultra-durable Mono-Drive sprung hub assembly in a completely modular design. Each diaphragm spring endures an exclusive four-stage heat treating process providing a consistent light pedal feel. Puck-style Friction Plates with high quality ceramic friction materials deliver high friction coefficient, superior heat capacity, and long clutch life. These Friction Plates uniformly transfer torque to a Mono-Drive sprung hub assembly which extends input shaft life and reduces driveline shock from torsional vibration. This kit includes a CNC-machined and dynamically balanced flywheel, pressure plate cover, diaphragm spring, face, puck-style ceramic friction plates, sprung Mono-Drive hub assembly, floater, patented Monoloc Collar, release bearing, alignment tool and pilot bearing (if needed). Mod-Twin clutches are fully rebuildable and most components can be ordered separately.

This Part Fits:

Year Make Model Submodel
2004-2014 Subaru Impreza WRX STI
2007,2011-2014 Subaru Impreza WRX STI Limited
2010 Subaru Impreza WRX STI Special Edition
2015-2021 Subaru WRX STI Base
2015 Subaru WRX STI Launch Edition
2015-2021 Subaru WRX STI Limited
2019 Subaru WRX STI S209
2016 Subaru WRX STI Series.HyperBlue
2018 Subaru WRX STI Type RA

  • Earn FAST points on this part!
  • Backed by real-world installs
  • FAST WC Team Approved

ACT 04-20 WRX STI Mod Twin HD Race Kit Sprung Mono-Drive Hub Torque Cap 895ft/lbs Not For Street Use

$2,104.00

Why Drivers Choose FAST of West Chester

  • I can't recommend this place enough. Being able to trust a shop in the performance world is big. The 2hr drive to get there, is worth knowing the job will be done right. Very happy to have found this shop, to
    support my builds going forward.


    Donald Wojnar
  • I recently had the pleasure of working with FAST of West Chester for some performance upgrades on my 2022 WRX, and the experience was nothing short of exceptional. I opted for a Borla S-Type exhaust and Cygnus Coilovers, and the team at FAST nailed the installation, fitment, and setup to a T.


    Adam Cranston
  • The team at FAST are excellence in every way. First, I consulted with Dave on mods for my HPDE track car. He listened and advised me on the best parts & mods to achieve my goals. He was patient & gave me space to research the options presented & worked with me through several changes before we built. Second, the build execution was flawless, proper heat shielding, bracing and poly everywhere. All components worked as advertised.


    Bryce Budd
  • This place has been my go to shop for all things Subaru. From simple service to performance parts and tuning, they have been top notch.


    William Brunell
  • Excellent shop. They installed a Cobb Stage 2 DP and Whiteline Sway bars and end links on my 2013 WRX. The work was done right and clean. The estimate was accurate. They were very knowledgeable, friendly and gave me the straight scoop on exactly what I was getting for the money
    and what I needed to get where I want to be with it. I'd recommend them
    to any car enthusiast.


    Devin Greco
1 of 5

Does it come with a warranty?

Most products we carry include a manufacturer warranty. Since we work with top performance brands, warranty coverage can vary by product. If you have questions about a specific item, reach out — we’re happy to help.

Do you offer installation help or advice?

Yes — we don’t just sell parts, we install and tune them too. FAST of West Chester is a real performance shop, and we’ve worked hands-on with many of the products we carry. If you have questions about fitment, installs, or building your setup, our team can point you in the right direction.

How fast is shipping?

Many of our products ship the same day or next business day, depending on availability. We work hard to get parts out fast so you can get your build moving without delays.

What’s your return policy?

Returns for exchange or refund are accepted within 30 days of receiving your order. Items must be in new, unused condition and in original packaging. If you have any questions, our team will help make the process easy.

Unlock 200 FAST Points Today!
Create your free account and get 200 FAST Points instantly.