Clutch Masters 12-13 Honda Civic Si 2.4L 6spd FX300 Sprung Clutch Kit w/ Steel Flywheel
This is the Clutch Masters FX300 kit for the ninth-generation Honda Civic Si with the 2.4L K24 engine and six-speed manual, sold as 08320-HRTZ-SK with the matching heavy steel flywheel in the box. It is aimed at Si owners whose stock clutch has started to slip after intake, header, tune or cam work, or who are adding a mild turbo or supercharger and want a clutch that still drives like a street car. Because the flywheel is included and built to factory weight, it goes in without an aftermarket engine management flash.
The FX300 pairs Clutch Masters' Power Plus I heavy-duty pressure plate with a sprung, steel-backed segmented Kevlar disc. Splitting the friction material into segments raises the pressure per square inch on the facing, which is how the kit reaches the 110 percent increase in holding capacity that Clutch Masters quotes for the FX300 street line. The sprung hub soaks up driveline shock, and Clutch Masters describes the Kevlar facing as non-abrasive, so it is easy on the flywheel face. Pedal effort goes up only slightly over stock.
The important detail on the K24 Si is the flywheel. Clutch Masters builds the 08320 kits as conversion kits: the factory flywheel will not work with this clutch, and the 08320 series is meant to run with the FW-320-SF steel flywheel. That flywheel is kept to OEM weight, which is why Clutch Masters says no Hondata FlashPro is needed with an 08320 kit. The lighter-flywheel 08240 kits are the ones that call for a reflash. This SK version includes the steel flywheel, so you are not ordering it separately.
Do a slip test first: in fourth gear at around 2,000 rpm, go to full throttle and watch whether the tach rises faster than road speed. Check the clutch master cylinder reservoir level and color, and look at the bottom of the bellhousing for oil or fluid, since a leaking rear main seal or slave cylinder will contaminate any new disc. A release problem with a firm pedal points at the hydraulics rather than the disc. Our slipping diagnosis guide walks through separating a slipping clutch from other drivetrain faults, and the manual transmission repair cost guide helps you budget the labor.
Our listing is titled for the 2012 to 2013 Civic Si 2.4L six-speed. The Clutch Masters application data for the 08320 FX300 kits lists the 2012 to 2015 Civic Si 2.4L six-speed, the 2009 to 2014 Acura TSX 2.4L six-speed and the 2013 to 2015 Acura ILX 2.4L six-speed with the OEM ECU. If your Si already has a lightweight flywheel or a different clutch conversion, tell us what is in it before ordering. The FX300 is rated by Clutch Masters for street use, not track use; for more holding power look at the FX400 high rev 6-puck kit. Send us your year and VIN if you want a fitment check, and browse more kits in our rebuild kits category.
| Brand | Clutch Masters |
| Part number | 08320-HRTZ-SK |
| Fits | Clutch Masters 12-13 Honda Civic Si 2.4L 6spd FX300 Sprung Clutch Kit w/ Steel Flywheel |
| Vehicle fitment | Honda Civic Si (2012-2013) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. Clutch Masters builds the 08320 kits around the FW-320-SF steel flywheel, which is kept to OEM weight, so no reflash is required. The 08240 kits with the lighter flywheel are the ones that need engine management.
No. Clutch Masters says the stock flywheel will not work with its 08320 and 08240 clutch kits. This SK version includes the matching steel flywheel, so the kit is complete for that part of the job.
Our listing is titled for 2012 to 2013, but the Clutch Masters application data for the 08320 FX300 kits covers 2012 to 2015 Civic Si 2.4L six-speed, plus 2009 to 2014 TSX and 2013 to 2015 ILX. Send your VIN if you want us to confirm.
Clutch Masters recommends the FX300 for street use and not for track use. For regular track time or more power, a ceramic puck kit such as the FX400 is the better match.
Drive at least 500 miles normally before launches or hard shifts. This lets the Kevlar facing and flywheel surface bed in for full holding capacity.
