Reinforced valve spring kit Opel Vauxhall Z20LET

€887.66 (tax incl.)

Reinforced valve spring kits for the Opel and Vauxhall 2.0 16V turbo Z20LET engine.

Brand: SUPERTECH
Engines: Z20LET (Astra G, Zafira A, Speedster, VX220)
Springs: double
Contents: springs, upper retainers, lower spring seats

Opel and Vauxhall engine covered

This kit is aimed at the Opel and Vauxhall Z20LET, a 2.0 litre 16-valve turbo engine found in the Astra G (turbo and OPC), Zafira A (OPC and GSi Turbo), Speedster Turbo and VX220 (Turbo and VXR).

The double springs in the kit take the place of the factory ones, together with their lower seats; the original collets stay in place.

SUPERTECH reinforced valve spring kit

Past the lobe's peak, the spring has to bring the valve home to its seat. At high revs inertia punishes weak springs: with too little load the valve lifts, bounces and can strike the piston, which tuners call valve float.

Seat pressure at 35.1 mm: 285 N for the SPRK-TS1012-Z20, 334 N for the SPRK-TS1015-Z20, both with double springs.

Valve spring kit technical specification

Part number	Brand	Springs	Outer / inner Ø	Seat pressure	Open pressure	Rate	Max lift	Kit contents
SPRK-TS1012-Z20	SUPERTECH	Double	Outer 27.5 / 20.0 mm Inner 20.0 / 15.2 mm	285 N at 35.1 mm	801 N at 10 mm		15.1 mm	16 springs, 16 upper retainers, 16 lower spring seats
SPRK-TS1015-Z20	SUPERTECH	Double	Outer 27.5 / 20.0 mm Inner 20.0 / 15.2 mm	334 N at 35.1 mm	867 N at 10 mm	53.8 N/mm	14.4 mm	16 springs, 16 upper retainers, 16 lower spring seats

Valve spring kit fitting details

Part	Opel and Vauxhall original	Reinforced spring kit
Spring		Kit specific: SPR-TS1012 or SPR-TS1015 (double)
Retainer		Kit specific: RET-TS55/T5
Spring seat	90410740	Kit specific: SEAT-TS-Z20
Collets	90354648	Original kept

Each SUPERTECH kit supplies 16 double springs, 16 RET-TS55/T5 upper retainers and 16 SEAT-TS-Z20 lower spring seats; the original collets stay in place.

With the valve closed, installed height runs from the base where the coil rests (lower spring seat) to the inner face of the upper retainer. The seat pressure we quote applies at this single height figure. If it grows (re-cut valve seats, for instance) the load falls by as many newtons per millimetre as the rate prescribes; see the table.

	SUPERTECH
Installed height	35.1 mm
Seat pressure at this height	285 / 334 N

Technical guide

Our brands

SUPERTECH is a California company that has supplied racing-grade cylinder head components for over three decades. Its springs are coiled from wire made of a chrome-silicon-vanadium alloy, and each production run then passes ultrasonic, radiographic and laser checks.

How to choose

Beefier springs hold the valve against the cam way up the rev range. That frees you to lift the rev limiter, swap in a livelier camshaft or raise boost without valve float creeping in. At 35.1 mm both kits press on the seat with 285 N or 334 N, as the table above lists. One limit to watch: the lift of your camshaft has to remain under the maximum lift printed for the kit, 14.4 to 15.1 mm depending on the reference.

Criterion	Key point
Choosing the pressure	The 64 and 75 lbs labels give the seat pressure in pounds, i.e. 285 and 334 N. Decide by weighing cam lift, your target revs and boost pressure: the higher each goes, the more pressure it asks for, up to the kit's lift ceiling. Resist overshooting, since an overly firm spring eats cam lobes sooner than needed.
Single or double spring	Each valve receives two nested springs in either kit; the two coils split the pressure and cancel part of each other's oscillation. A one-coil spring would feel closer to the stock setup. Upper and lower retainers come in each kit.

When reinforced springs become necessary

Camshaft sharper than the standard one
Rev ceiling you want to move back
Boost pushed past the factory setting
Head restored for circuit or rally work
Tired factory springs, or valves that float once revs climb

Compatible vehicles

Model	Engine code	Years
Opel Astra G (T98) 2.0 16V Turbo (F07, F67)	Z20LET	2000-2005
Opel Astra G (T98) 2.0 OPC (F08, F48, F35, F67)	Z20LET	2000-2005
Opel Speedster (E01) 2.0 Turbo (R97)	Z20LET	2002-2006
Opel Zafira A (T98) 2.0 OPC (F75)	Z20LET	2001-2005
Vauxhall Astra Mk IV (G) (T98) 2.0 16V Turbo, 2.0 SRi Turbo (F08)	Z20LET	2000-2005
Vauxhall VX220 (E01) 2.0 VXR, 2.0 i Turbo	Z20LET	2001-2005
Vauxhall Zafira A (T98) 2.0 GSi Turbo	Z20LET	2001-2005