Competition Clutch 16+ Honda Civic 1.5T Stage 2 Organic Steel Flywheel w/ 17lbs
A tuned 1.5 liter turbo Civic Si makes more torque than the factory clutch was built to hold, and a dual mass flywheel that rattles at idle is a common complaint as these cars age. Competition Clutch 8091-STU-2100 answers both: it pairs a Stage 2 organic clutch with a 17 lb single mass steel flywheel for the manual 1.5T Civic. If your Si slips in third or fourth gear after a tune, the engagement point has moved high on the pedal, or you hear chatter and rattle from the bellhousing, this is the kit buyers are looking for.
Competition Clutch describes its Stage 2 2100 series as the step for drivers moving from daily driving to spirited track use. It supports significantly more power than stock with more torque capacity and stronger grab, while staying manageable on the street, and is meant for high performance street use and occasional track days. The organic facing engages progressively, so stop and go traffic stays livable.
The STU in the part number refers to the lighter of the two steel flywheels Competition Clutch offers for this platform. This kit uses the 17 lb version; the 8091-ST-2100 kit with the 22 lb flywheel keeps more rotating mass for smoother low rpm driving. The lighter flywheel lets the engine rev and drop rpm faster between shifts, at the cost of slightly more care on hill starts. Our dual mass vs single mass flywheel guide explains the trade-off.
Do a slip test in third gear from about 2,500 rpm at full throttle; if rpm climbs faster than road speed, the clutch is slipping. Rule out hydraulic problems first by bleeding the system and checking for a soft pedal. If grinding into gears is your main complaint, read our Civic Si third gear grinding fix because synchro wear is not cured by a clutch. For budgeting, see our manual repair cost guide.
Competition Clutch catalogs its 8091 kits for the 2017-2023 Honda Civic Si with the 1.5 liter turbo and six speed manual. Our listing title reads 16+, but the 2016 1.5T Civic sedan came only with a CVT, so this kit does not apply to it or to any CVT Civic; our Honda CVT maintenance guide covers those cars. Other manual 1.5T Civics, such as the Sport hatchback, may share hardware, but confirm with us first. The Civic Type R uses a different 2.0 liter engine and needs a different kit. Send us your year and VIN and we will check it before it ships.
If you need more holding power for a big turbo build, look at the Stage 3 segmented ceramic version.
| Brand | Competition Clutch |
| Part number | 8091-STU-2100 |
| Fits | Competition Clutch 16+ Honda Civic 1.5T Stage 2 Organic Steel Flywheel w/ 17lbs |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. The 2016 1.5T Civic sedan came only with a CVT. Competition Clutch catalogs the 8091 kits for the 2017-2023 Civic Si with the six speed manual.
Both use the Stage 2 organic clutch. The STU kit comes with the lighter 17 lb steel flywheel, and the ST kit uses a 22 lb steel flywheel for a smoother feel at low rpm.
Yes. Competition Clutch designs Stage 2 for high performance street use and occasional track days, and organic facing engages smoothly in traffic.
No. The Type R uses a 2.0 liter turbo engine with different clutch hardware. This kit is for the 1.5 liter turbo manual Civic.
Competition Clutch publishes 8091-STU fitting and installation instructions that list the torque specs for the hardware it supplies.
