Clutch Masters 12-13 Honda Civic Si 2.4L 6spd FX350 High Rev Sprung Clutch Kit w/ FW *Req FlashPro
This Clutch Masters FX350 kit is for the 2012 and later Honda Civic Si 2.4L six-speed that already runs a Hondata FlashPro or other engine management. Sold as 08240-HRFF-SK, it pairs the FX350 Fiber-Tough clutch with Clutch Masters' lighter FW-037-SF flywheel, so the engine revs up and drops between shifts faster than it does on a factory-weight setup. It is meant for a tuned K24 with cams, head work, medium boost or nitrous that has outgrown the stock clutch.
The clutch side is the FX350: a Power Plus I high-leverage pressure plate over a heavy-duty segmented disc with steel-backed Fiber-Tough facing, a sprung hub and a Marcel spring wafer. Clutch Masters rates it at a 110 percent increase in holding capacity over stock, slightly ahead of the FX300, with more aggressive engagement and some chatter. It is aimed at street cars that see the occasional track day.
The flywheel is what sets this kit apart. Clutch Masters' K24 Si clutches will not bolt to the stock flywheel, and kits that begin with 08240 use the FW-037-SF, which is lighter than factory. Clutch Masters states that a lighter flywheel will set a check engine light on these cars unless the engine management is tuned for it, which is why the listing says FlashPro required. Less rotating mass sharpens throttle response and rev-matching, but it also makes pulling away from a stop a little less forgiving.
Before spending on a clutch, confirm the slip: fourth gear, about 2,000 rpm, full throttle, and watch whether rpm climbs ahead of speed. Data logs from the FlashPro help here, because a flare in rpm with no change in vehicle speed is clear evidence. Check for oil at the bellhousing and for a leaking slave cylinder, and make sure the pedal returns properly. Our slipping diagnosis guide covers the full process, and the manual transmission repair cost guide helps you budget the job.
Our listing is titled 2012 to 2013 Civic Si 2.4L six-speed. Clutch Masters' application data for the 08240-HRFF FX350 covers 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. Plan for the tune before the car is driven: without engine management to suit the lighter flywheel, expect a check engine light. If you want to keep the factory ECU untouched, order the FX350 kit with the OEM-weight steel flywheel instead. Send us the year and VIN for a fitment check, or browse the rebuild kits category.
| Brand | Clutch Masters |
| Part number | 08240-HRFF-SK |
| Fits | Clutch Masters 12-13 Honda Civic Si 2.4L 6spd FX350 High Rev Sprung Clutch Kit w/ FW *Req FlashPro |
| 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 |
Kits that begin with 08240 use Clutch Masters' FW-037-SF flywheel, which is lighter than stock. Clutch Masters says that lighter flywheel will trigger a check engine light unless the car has a Hondata FlashPro or other engine management tuned for it.
Choose the 08320 version of the FX350 instead. Its FW-320-SF steel flywheel is held to OEM weight, so the factory ECU works without a reflash.
No. Clutch Masters states the stock flywheel will not work with its K24 Si clutch kits. This SK kit includes the FW-037-SF flywheel it is designed for.
Clutch Masters lists the 08240-HRFF for 2012 to 2015 Civic Si 2.4L six-speed, 2009 to 2014 TSX 2.4L six-speed and 2013 to 2015 ILX 2.4L six-speed, even though our listing title says 2012 to 2013. Send your VIN to confirm.
The engine revs and falls faster, which helps rev-matching and response, but it carries less momentum when pulling away, so take-offs need a bit more care, especially with the grippier FX350 disc.
