1JZ or 2JZ – What’s the best motor swap?

Toyota Supra for sale in Japan at JDM EXPO

The Supra is legendary and everyone wants to put JZ in their car but which one is the way to go? What’s the difference between the 1JZ and 2JZ motors?

As you might have imagined, the 1JZ came before the 2JZ. It came in a variety of Toyota JDM cars such as the Chaser, Soarer, Supra MK III (Japan only) and Crown. It was a 2.5L straight six, with a 86mm bore and a 71.5mm stroke. The 1JZ-GTE, which is the top of line twin turbo model of the 1JZ, is the one that comes to mind when someone thinks “1JZ” and is the one we’ll be referring to here.

motor
1JZ

The 1JZ came with parallel twin turbos, and later 1JZ’s came with VVT-i (Variable Valve Timing with Intelligence). The biggest difference between the 7MGTE, found in USDM MK3 Supras, and the 1JZ is the strength. The 7MGTE was a great engine, but unfortunately was known to have a variety of headgasket and cylinder head issues. The 1JZ is pretty similar, but doesn’t see nearly the same amount of issues.

2jz
2JZ

Unlike the 1JZ, the 2JZ-GTE came with a sequential turbo setup, meaning that the power band is much broader thanks to turbos of different sizes. This same setup was also seen in the Mazda RX-7. A small turbo gives low rpm power and helps spin up the bigger turbo for high rpm power and reduced turbo lag. The 2JZ shares most of the components of the 1JZ, with the biggest difference in the displacement as the 2jz was bumped up to 3L. The 2JZ retains the 86mm bore that the 1JZ has, but its stroke is increased from 71.5mm to 86mm. This makes the 2JZ what is referred to as a “square” engine, meaning the bore and stoke measurements are equal. This provides a better balance between low end torque and high end horsepower.

1JZ vs 2JZ: Stock vs. Stock
dyno chart
Going by the dyno charts, the 2JZ makes around 30 horsepower and 20 lb-ft torque more than the 1JZ. This isn’t surprising, giventhe 2JZ has an extra .5 liters of displacement.

Important to notice though is how the 1JZ dyno graph shows the horsepower continually going up. Its a very linear gain throughout the rpm range which is great for track use. The power is predictable when getting on and off of the throttle.

The 2JZ dyno graph the horsepower basically just goes up rapidly and then flattens out. The power goes up in the lower RPMs, flattens, then goes down in the upper RPMs. This is great for street use because power is available low down, where most people do their driving.

2jz modded

1JZ vs 2JZ: Modified vs. Modified

While they respond to modifications nearly identically, the 2JZ of course will make a little bit more power and torque thanks to its extra displacement.

Parts are nearly identical in price, being basically the same, however when including the price of purchasing the engine itself it’s generally cheaper to build a 1JZ. The most commons upgrades would be a big single turbo setup. Like Nissan Skylines, the factory turbos have issues when the boost is turned up.

1JZ vs 2JZ: Engine Strength

Contrary to what most people believe, the 1JZ and the 2JZ are pretty much equally as strong. Their connecting rods are identical other than the length since the 2JZ has a longer stroke. The crank and pistons are pretty much equally as strong as well.

The reason most people think that the 2JZ is stronger is because it can hold higher power levels. A general rule of thumb is that the 1JZ stock bottom end is good for about 650-700 horsepower and the stock 2JZ bottom end is good for about 800 horsepower.

Both are some of the strongest factory engines to ever come in a production automobile and part of the allure. Very few engines in the world can hold up to 1,000 horsepower or more.

2jayz
Which One is Better?

The 1JZ is thought to be better for drifting, especially when on a budget. The shorter stroke means it loves to hang out at high RPM’s, but lacks low end power. It takes a fairly long time to spool up the turbo(s) because of the short stroke.

The 2JZ is generally regarded as better for street use. The larger displacement and longer stroke really helps give them engine some low end grunt. The longer stroke also means it can spool up the turbo(s) much faster, making it more practical for street use.

So, which one is better? It’s hard to go wrong either way since they are both fantastic engines and quite similar but since most of people are looking for a swap for their street cars, the 2JZ is probably going to be the better engine.

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