Supertech 13.80mm Max Lift Single Valve Spring Kit | 2017+ Honda Civic Type R (SPRK-K20C-1) Volkswagen Golf GTI MK8.5 (2025+) Dyno Proven power increase of

Dyno Proven power increase of 11 HP and 9 Lb

Part Number: 827-731

Rear -  11

Can be used on daily driven street cars and is highly recommended for Street or Track setups

+15 HP / +17 lbs

Supertech 13.80mm Max Lift Single Valve Spring Kit | 2017+ Honda Civic Type R (SPRK-K20C-1) Volkswagen Golf GTI MK8.5 (2025+) Dyno Proven power increase ofFITS: K20c1 , k20c4 engines Supertech Spring Retainer kits are precision matched sets for a complete valvetrain overhaul. Developed for the performance enthusiast that wants the best the industry has to offer, Supertech Spring Retainer kits are second to none in terms of performance, quality and value. Features Seat Pressure: 77 @ 40. 60 Open Pressure: 176 @ 10 Max Lift: 13. 80mm Coil Bind: 27. 30mm Rate: 9. 9 Kit spring: SPR H1003S Retainer: RET 1003