Supertech KPR-6S/7 6mm Single-Groove Valve Spring Locks/Keepers/Split Collets/Cotters for Audi VW 1.8T AEB, 2.0T TFSI EA113/EA888, VR6 12v/24v, BMW M50 M52 M54 N54 S50 S52 S54, Opel Vauxhall Z20LET Z20LEH, Renault F4RT, GM Ecotec 2.0 2.2 2.4

Supertech KPR-6S/7 6 mm Single-Groove Split Collets for Performance Cylinder Heads

Part number: KPR-6S/7

Build your head with confidence. These Supertech split cotters are engineered for 6 mm stems and single-groove valves, giving a precise, positive grip on the valve stem for hard use, big boost and high rpm. Ideal for turbo builds, fast-road setups and track-day engines where dependable top-end hardware matters.

At MJ Modifications we have installed these in our own projects and customer engines with excellent results on fit, consistency and long-term reliability. If you are refreshing the valve gear, pairing with performance springs or swapping to single-groove valves, KPR-6S/7 is the go-to keeper set for a secure, repeatable clamp on the stem taper.

Key reasons to choose KPR-6S/7

• 6 mm stem split keepers for single-groove valves – accurate seat and secure capture
• Built for high revs, forced induction and endurance use
• Perfect for performance head builds that demand consistent valve control
• Trusted by engine builders across VAG, BMW, GM Ecotec and Renault platforms

Compatibility highlights

Popular applications include the engines below. If you need a compatibility check for your exact cylinder head, contact us and we will confirm.

• Audi 1.8 20v Turbo AEB 058
• Audi 2.0 TFSI EA113 and EA888 variants including BPY
• Audi 2.7T APB biturbo
• Audi 4.2 V8 BHF and BHK
• Volkswagen VR6 12v and 24v including 2.8, 3.2 and 3.6 BDF BJS BUB BLV BHK CGRA CNNA
• Volkswagen 2.5 five-cylinder CBTA CBUA BGP BGQ BPR BPS
• Volkswagen Golf GTI and R32 applications as above
• BMW M42, M50, M52, M54B30
• BMW N54B30A twin turbo
• BMW S50, S52, S54B32 including E36, E46, M Coupe and M Roadster
• Opel Vauxhall Z20LET Z20LEH Ecotec including GSi, OPC and VXR
• Renault F4RT 2.0 Turbo Megane RS 250 and RS 265
• Chevrolet and Pontiac GM Ecotec 2.0 2.2 2.4 including L61 and LAP plus 2.0 supercharged and turbo variants

Fitment notes

• For use with single-groove valves
• Two keeper halves are required per valve

What you receive

• 1 x Supertech 6 mm single-groove split keeper KPR-6S/7
  Quantity 1 equals one keeper half. Two required per valve.

Used by enthusiasts and professionals

Customers consistently report clean installation and rock-solid stem retention with these collets across boosted and naturally aspirated builds. We use them in-house because they simply work.

Installation and support

Need fitting or a full head build. MJ Modifications offers professional installation in Warwickshire. Request a quote or compatibility check at info@mjmodifications.co.uk.

Search-friendly terms

6 mm valve cotters, split collets, valve keeper halves, single notch valve cotter, valve spring wedges, single groove stem retainers, VAG 1.8T AEB keepers, TFSI EA113 EA888 stem cotters BPY BWA, VW VR6 R32 collets 3.2 3.6, BMW N54 M54 M50 M52 S50 S52 S54 valve cotters, Opel Vauxhall Z20LET Z20LEH Ecotec keepers, Renault F4RT Megane RS valve collet, GM Ecotec 2.0 2.2 2.4 L61 LAP valve keepers.