Since the A90 Supra was announced, a lot of talk has come up about the engine it uses and if it will be anywhere near as good as the 2JZ. You don’t have to look very hard to find people complaining that Toyota should’ve used the 20-year-old 2JZ or the 10-year-old N54. (put some screenshots of stupid people content)
With tuners starting to get their hands on the A90 Supra and beginning to push the B58 engine, the question remains: is the 2JZ better than the B58? Let’s dive in and find out.
Before diving into the differences of each engine, let’s quickly cover the basics of these engines, because they are separated by 20 years of engineering. The 2JZ, as you probably know, is the second engine in Toyota’s JZ engine family. It was developed during the era when Toyota over-engineered everything they built.
It’s a 3 liter, inline-6 engine with a bore of 86mm and a stroke of 86mm, making it a square engine. It featured a very strong cast-iron block, very strong internals, and some of them feature Toyota’s VVT-i variable valve timing system.
There are a few 2JZ variants, however, the version we’re going to reference in this video is the 2JZ-GTE, which was the top-of-the-line version. What made the 2JZ-GTE such a high-performance engine at the time was its twin-turbo system, which allowed it to output over 300hp and 300lb-ft of torque in stock form.
Of course, this was under Japan’s “gentlemen’s agreement” which limited manufacturers to 300hp, however, it’s argued the 2JZ was underrated and produced more power than Toyota claimed.
The 2JZ-GTE was produced from 1991 to 2002. When Toyota was still producing the 2JZ, you could find it in a bunch of different applications. The 2JZ-GTE, specifically, was used the Toyota Aristo, and the Supra. Its use in the Supra is, in part, what’s made it so popular and legendary.
The B58 is also a 3-liter engine, like the 2JZ, however, it uses an under-square design with a bore of 82mm and a stroke of 94.6mm. The under-square design makes it inherently less of a high-revving engine but drastically improves low-end torque.
Just like with the 2JZ, there are quite a few different versions of the B58, however, for this video, we’re going to B58B30, which is the variant that Toyota is using for the A90 Supra. This version of the B58 comes with an advertised power output of 335hp, however, through independent dyno testing, it looks like Toyota underrated this engine.
Bottom End and Block
Alright, with the most basic stuff out of the way, let’s look at the bottom end and block of each engine. The 2JZ features a closed deck, cast-iron block, with a forged crankshaft. The pistons and the rods also both very beefy and way overkill for the stock power output. Under the crankshaft, you’ll find a girdle which ties the skirts of the block and the crankshaft main caps. To help keep the pistons cool, the 2JZ features oil-squirters, which spray oil on the bottom side of the piston.
One of the biggest differences between the 2JZ and the B58 is the material of the block. While the 2JZ uses a super-strong, but heavy cast-iron construction, the B58 uses an aluminum construction. Although cast-aluminum isn’t as strong as cast-iron, it’s significantly lighter and offers far superior thermals.
The B58 also features a crank girdle like the 2JZ, which massively improves block-rigidity and the strength of the bottom-end. The crankshaft is forged and very beefy, and the rods and pistons also use a pretty beefy design. Like the 2JZ, the B58 features oil squirters help keep the pistons cool.
To put it simply, both engines have incredibly strong bottom ends and they are both very capable. People haven’t been pushing the B58 engine for a very long time since it’s relatively new, however, both stock bottom ends are capable of holding up to over 600hp, with the 2JZ holding up to a bit more than that.
Top End and Valvetrain
Moving from the bottom end to the top-end, it’s clear the B58 has a plethora of modern upgrades and changes. Both engines feature a dual-over-head-cam design with variable camshaft timing. But that’s pretty much where the similarities end.
The 2JZ uses a simple shim over bucket design. This system works by basically have the camshaft lobe press down on a bucket that sits over the spring. It’s a pretty basic system, but it gets the job done. It also features Toyota’s VVT-i system, which allows camshaft timing to be changed on the fly.
On the other hand, B58 uses a roller-rocker system. Where it gets complicated with the B58 is with the intake cam, which uses two rocker arms with an eccentric shaft to change the rocker ratio. This system allows for more lift depending on what the ECU tells the system to do. The B58 also features cam phasing to change cam timing on the fly like the 2JZ.
Other notable features on the top-end of the B58 engine include an integrated exhaust manifold which means only two exhaust ports are exiting the cylinder head, instead of six. The big change with the B58’s valvetrain system is that the timing chain and the entire system is on the back engine where the transmission is mounted, rather than the front like most engines.
Another big change you’ll find on the cylinder heads is the fueling system. When the 2JZ was around, direct injection wasn’t a common thing to see on a gasoline engine. The 2JZ-GTE uses the typical fuel system that most of us are used to, while the B58 uses a direct injection fuel system that sprays fuel directly into the cylinder.
Rather obviously, both of these engines are turbocharged. The 2JZ-GTE uses a twin-turbo system, where the B58 uses a single twin-scroll turbo. The twin-scroll turbocharger is part of the reason for the internal exhaust manifold. By using three cylinders for each scroll of the turbo, scavenging is massively improved, turbo lag is improved, and the entire system becomes much more efficient.
Both systems use fairly small turbochargers which minimize lag and produce tons of low-end torque, but don’t offer very much top-end power. For anyone who wants to make big power, both engines will require a big turbo. Another cool difference of the turbo system is the B58’s intercooler, which is placed inside the intake manifold.
Of course, reliability is pretty much paramount when developing engines. Toyota helped BMW with the development of the B58, however, the B58 features a lot of modern technologies which aren’t exactly super reliable. Where the 2JZ was a relatively simple engine, the B58 is quite a bit more complicated, and ultimately probably won’t be as reliable in the long-term.
Only time will tell how reliable the B58 is in stock and modified forms. Not too surprisingly, most people on the internet only seem to care about the absolute peak numbers that engines are capable of, and the 2JZ-GTE is well known for being able to withstand 800 horsepower or more on a stock bottom end, and significantly more with a built bottom end.
Which One is Better?
Already I can see people freaking out, claiming that the B58 isn’t nearly as strong, and while it’s probably true that the B58’s bottom end isn’t as strong as the 2JZ’s bottom end, why does that matter? It’s not like average car buyers are sticking massive turbos on everything they own and pushing the limits.
What the engine is capable of surviving in stock form is a nearly useless metric for the majority of car owners and enthusiasts. Toyota and BMW have no reason to build an engine capable of withstanding those kinds of power levels because that’s not what determines how the engine performs in stock form, how it delivers power, or how efficient it is.
To put it simply, the 2JZ is probably more reliable and it can withstand more power on a stock bottom end. That’s not to say the B58 is a weak engine, because as of right now multiple tuners are pushing it as far as 700whp.
As far as what’s possible with the help of the aftermarket, it’s not known to the full extent right now. With so many new tuners hopping on board the B58, it won’t be long until we see these engines eclipse the 1,000hp mark.