Reinforced exhaust valves Toyota GR Yaris GR Corolla G16E-GTS

Toyota engines covered

The G16E-GTS is the 1.6 litre, 12-valve turbocharged three-cylinder Toyota developed for the GR Yaris from 2020, then carried over to the GR Corolla in 2023.

Its 6 original exhaust valves carry part number 13715-18010, superseded by 13715-18020 since April 2024; their stem measures 5.465 to 5.480 mm and their length 117.05 mm. On an engine running this much boost, they sit in the gases that drive the turbine.

SUPERTECH and FERREA reinforced exhaust valves

The G16E-GTS three-cylinder has only 6 exhaust valves, but each of them sees very hot gases go by that head straight off to drive the turbine. On the metal side, the valve head goes past 1,000 °C on this turbocharged engine, when an engine without a turbo holds it near 760 to 870 °C. That heat flow leaves mostly through the seat, about 75 %, then through the guide, around 20 %. With an EV8 steel as a marker, strength falls from 550 MPa at 600 °C to 300 MPa at 800 °C. The higher the boost goes, the harder life gets for the head: it heats up, tires, twists, and contact with the seat is no longer tight.

Reinforced valves replace this steel with nickel-bearing metals. FERREA supplies here a Competition Plus cut from Super Alloy, designed for turbo engines, which the brand credits with 20 % extra thermal strength and 25 % longer seat life. SUPERTECH relies on Inconel, which retains 860 MPa at 730 °C and 554 MPa around 815 °C, roughly 85 % better than EV8 steel near 800 °C; its sodium filled stem, liquid from 97.8 °C, helps the head get rid of its heat, and its head is flat.

These two valves keep the engine's 32 mm head and a length of 117.0 to 117.1 mm, all but equal to stock. Burnt gases find the same flow area as on the factory engine: no exhaust seat needs enlarging, only the usual reconditioning of the cylinder head is required.

Exhaust valve technical specifications

The F2458P is standard size, in Super Alloy; the TEVI-2033-HS is Inconel with a sodium filled stem.

Valve fitting

When refitting, check that the chosen collets match the groove of the valve.

The 32 mm head needs no seat machining beyond the usual cylinder head refurbishment.

On this engine, the original exhaust guides exist in a +0.05 mm repair size (11127-18010 then 11127-18011) if the bore is worn.

Technical guide

Our brands

	SUPERTECH, a Californian company that came out of Silicon Valley, has created valves, titanium retainers, valve guides and springs for competition for three decades. The chosen metal, stainless steel, titanium or Inconel, varies with the engine, and the part is validated by rally, track or drag racing teams.
	FERREA Racing Components was born in 1978, when Horacio Ferrea teamed up with Daniel Urrutia. From its Florida and Argentina factories, stainless, titanium and nickel superalloys leave as valves for engine builders competing in NASCAR or drag racing.

How to choose

Both valves share the 32 mm head of the G16E-GTS; what sets them apart is the material and the way the stem gets rid of heat, two points to weigh against the boost level you aim for and the use of the car.

When reinforced valves become necessary

• Remap that sends turbo boost up (Inconel version advised)
• Upsized or higher flowing hybrid turbo
• More aggressive camshafts or harder springs
• Rally, circuit or timed hill climb entries
• Cylinder head rebuilt with marked or burnt exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 13715-18010 (08/2020 to 04/2024); 13715-18020 (from 04/2024)

Don't forget the inlet valves

Whenever a G16E-GTS cylinder head is opened, take the opportunity to renew the whole inlet side and every valve stem seal as well, to put it all back as new. Inlet side: