When it comes to horsepower, Australians are crazy. In fact, so much so that they have just about ruined burnout contests for us entirely. Why? Because every burnout contest we hold here is now measured by Australian standards, and they rarely hold a candle. So we probably shouldn’t have been surprised when we stumbled across Street Machine Magazine’s project MX5.7—but this thing takes crazy to a new level.
As you’ve probably already guess, they decided to take an ND Mazda Miata and stuff a twin turbo’d LS1 between its fenders. Not only that, but they decided that the car needed a solid rear axle and all the accompanying drag racing gear to boot. When they were done, the only Mazda part left on the thing was a hacked up Miata chassis—just the way we like it.
In true Australian fashion, they hung both Garrett GTW3684 snails outside the car just above the hood. Backing the 5.7L mill is a powerglide two-speed auto which sends power outback to a Ford 9-inch stuffed with a spool and 3.25 gears. The whole shebang is running on pump E85 and really lays down some power.
When they finally got it on the dyno, they started turning up the boost on a very safe tune to keep everything happy. On just 9 pounds of boost, and very conservative timing, the car made 457.1 horsepower. On the next pull, the car managed 649.0 horsepower, though on much more boost than the team intended but still with the conservative timing. It turns out they are having some serious boost creep issues that will have to be solved with larger wastegates. The car then proceeds to make 449.1 horsepower without wastegates entirely.
In a car that should weigh no more than 2,500 pounds, that kind of power is insane. While there are still kinks to be worked out in the little ND Miata, it’s actually one we wouldn’t be embarrassed to be seen in. Kudos to our friends on the other side of the world for building it. Street Machine Magazine sure knows their way around an LS swap.