Product successfully added to your shopping cart
Quantity
Total
There are 0 items in your cart. There is 1 item in your cart.
Total products
Total shipping To be determined
Total
3.0L 24v - B58
Manufacturers
3.0L 24v - B58
View larger Warning: Last items in stock!
New product
Set of 12 reinforced inlet valves for the TOYOTA GR Supra (DB) with the B58B30 engine.
The fifth-generation GR Supra (DB) uses the BMW B58B30: a 3.0-litre turbocharged inline six with roller rockers, hydraulic lash adjustment and Valvetronic variable lift on the inlet side. It delivers 340 hp from 2019, then 387 hp from 2020.
The engine has 12 BMW 11 34 7 633 699 inlet valves, 30.1 mm head and 5 mm stem, held by 11 34 1 438 142 collets. A remap, a bigger turbo or higher boost puts them through more heat and harder impacts.
On every cycle the inlet valve lets in the air compressed by the turbo, drops back onto its seat and slides in its guide. It runs between 400 and 550 °C, where the original chrome-silicon steel falls from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % less strength.
SUPERTECH valves are made from a racing stainless steel of the EV8 family, which keeps 650 MPa at 500 °C and 550 MPa at 600 °C, 30 % and then 120 % more than the original steel. Black nitriding makes the surface harder and smoother: the stem rubs and wears less in the guide.
SUPERTECH also offers a +1 mm oversize: the head goes from 30.1 to 31.1 mm, stem and length unchanged. The opening at the seat grows, the cylinder fills better and the engine gains power, provided the inlet seats are cut to this size.
| Part number | Brand | Size | Head Ø OEM 30.1 mm | Stem Ø OEM 5 mm | Length | Grooves | Material |
|---|---|---|---|---|---|---|---|
| TIVN-1058-12 | SUPERTECH | Standard | 30.1 mm | 5 mm | 99.5 mm | 1 | Black nitride stainless steel |
| TIVN-1058T-12 | SUPERTECH | Standard | 30.1 mm | 5 mm | 99.5 mm | 3 | Black nitride stainless steel |
| TIVN-1058-1-12 | SUPERTECH | +1 mm | 31.1 mm | 5 mm | 99.5 mm | 1 | Black nitride stainless steel |
TIVN-1058-12 and TIVN-1058-1-12: single groove valves to be fitted with KPR-5.0-7S collets.
| Part | BMW original | Reinforced |
|---|---|---|
| Valve collets | 11 34 1 438 142 | KPR-5.0-7S (1 groove) |
| Valve stem seals | Kit 11 34 0 034 068 | VSI-BM50-I-12 (inlet) |
| Valve guide |
The number of grooves on the valve and the collets must match: the single groove valves (TIVN-1058-12 and TIVN-1058-1-12) are fitted with KPR-5.0-7S collets, never with the original ones. The TIVN-1058T-12 has 3 grooves.
The +1 mm size needs inlet seats cut to 31.1 mm. Clearance is taken up hydraulically: no adjustment is needed after replacing the valves.
Oversized-head valves are not recommended on BMW VANOS engines: depending on camshaft timing, a larger head may touch the piston.
 | SUPERTECH works out of San Jose, California, and has supplied valvetrain parts for racing engines for more than 30 years: valves, springs, retainers and guides. Each part number starts from a specific cylinder head, goes through ultrasound, X-ray and laser checks, then is proven with engine builders, from drag strip to circuit. |
The groove is where the collets lock the valve under the retainer. Their number decides which collets to fit and how well the valve holds at high revs.
| Criterion | Option 1 | Option 2 |
|---|---|---|
| Size | Standard size 30.1 mm head, for inlet seats still at factory size. | +1 mm oversize 31.1 mm head: more air in (about 10 to 12 cfm per mm of head). Seats to be cut; not recommended with VANOS. |
| Grooves | 3 grooves Original design, stem free to rotate: for an engine close to stock. New collets recommended. | Single groove KPR-50/7S collets clamp the stem: unloaded groove, better strength with stiffer springs and high boost. |
| Model | Engine code | Power | Years |
|---|---|---|---|
| GR Supra 3.0 (DB) | B58B30C | 340 hp | 2019- |
| GR Supra 3.0 (DB) | B58B30B | 387 hp | 2020- |
OEM part number (inlet valve, BMW B58B30 engine): 11 34 7 633 699
A rebuilt B58 cylinder head also gets new exhaust valves. They are available here:
| B58B30 exhaust valves → |
