Why the A90 Supra's engine is a great successor to the legendary 2JZ

18 Jan 2019

As everyone knows by now, the new A90 top-of-the-range Supra will be fitted with BMW’s B58B30O1, a 335hp, 500nm single twin-scroll turbo powerhouse and upon its announcement the reactions were mixed.

Full Specifications and updates over the N55

Compared with its BMW N55 predecessor, the B58 features a 20% increase in boost pressure, a closed-deck engine block design, an increase in compression ratio to 11.0:1 and a slight increase in displacement from 2,979 cc to 2,998 cc. The bore is 82 mm and the stroke is 94.6 mm. The fixtures for the VANOS solenoid valve actuators of the B58 are not in the cylinder head, but in the cylinder head cover. The mounting of the VANOS solenoid valve actuators has also changed. The B58 engine is equipped with a cylinder head featuring transverse flow cooling. In the case of cross-flow cooling, the coolant flows from the hot exhaust side to the cooler intake side. This has the advantage of enabling a more uniform heat distribution to prevail throughout the cylinder head. Loss of pressure in the cooling circuit is also prevented. The cylinder walls of the B58 engine are coated with electric arc wire spray (LDS). In this procedure, a conductive metal wire is heated until it melts. The melt is then sprayed onto the cylinder barrels at high pressure. This layer of ferrous material is roughly 0.3 mm thick, extremely wear-resistant and facilitates an efficient transfer of heat from the combustion chambers to the crankcase, and from there to the coolant ducts. Its advantages are Lower weight, High wear resistance, Good heat dissipation to the crankcase and Lower internal friction due to excellent lubrication

Overall, the new B58, being an updated version of the great N55 is a great engine with great tuning potential. It’s a rev-happy, efficient modern engine with a longer stroke. As of now, you can easily tune it to over 500whp relatively easily. BMW have been known for making some of the best engines to ever come out (M50, S54, S55). While the B58 is a contemporary engine, its beautiful sound could very well be out of a 1990s car and its performance is incredible, combined with a chassis as good as the new Supra’s, make for a great sports-car and a great successor to the legendary A80 Supra

Source: BMW official B58B30O1 engine manual

Comments

I think it’s worth mentioning that it can’t take as much boost with the 11:1 compression, and that the new method of making the cylinder walls makes it impossible to machine the block.

But there’s a catch , the VR38 from the GTR has pretty much the same problem , the cylinder walls are plasma honed , in a way similar to the b58 . So everyone in the first years of production was saying “it’s impossible to bore” but after some years and before the billet blocks a lots of builders have started to increase the bore on the VR . I don’t know how , but today is pretty much possible , and there’s even a video of JUN machining a VR for their yellow showcar , so , i’m not pretty much sure that’s the same , but i have great hopes because if it’s not possible well, the only solution will be a billet block , even for 600 whp 😂

The engine got direct injection so 11:1 is no problem, when running higher boost pressure

I was going to say that the compression ratio is very high for a turbo (more than some naturally aspirated petrol cars) so on paper it doesn’t sound like it would tune very well.