In the world of modified cars, engine swaps are quite a common practice. And while certain engines are the go-to powertrains for that, there are those that are more unconventional. This YouTube video from AutoTopNL give a good example because it features a BMW E46 M3 with an S85 engine from a BMW E60 M5. But that’s not all it has.

About The Car

While the BMW E46 M3 is still considered, by some, to be one of the greatest driver’s cars ever made. Normally, it would come with an S54, 3.2-liter, normally-aspirated inline-six that makes 343 horsepower at 7,900 RPM and 269 pound-feet (365 Nm) at 4,900 RPM. This propels the 3,296-pound (1,495 kg) German coupe to 60 mph (97 km/h) in 4.9 seconds.

Apparently, someone thought that the inline-six doesn’t have a strong enough punch and replaced it with a 5.0-liter normally-aspirated V-10 from a BMW E60 M5. That one makes 507 horsepower at 7,750 RPM and 383.5 pound-feet (520 Nm) at 6,100 RPM.

But don’t think for a second that the V-10’s performance is hindered by the horrible SMG, automated manual, most E60 M5s came with. This E46 M3 has received the seven-speed DCT unit from a BMW E92 M3. In fact. It’s currently the only E46 M3 in the world to feature such a setup.

The car is a real sleeper and only the tall E92 M3 GTS rear wing suggests something is off. The tires are Nankang AR-1 all-around and are “basically slicks”, with only minimal grooving to make them (barely) street-legal. The car features a square stance, with both axles featuring 265mm width tires. Behind the 18-inch E46 M3 wheels hide new AP racing brakes that do a good job at stopping the car as fast as it accelerates. The M3 also features a lightweight flywheel, which makes the V-10 even happier to rev.

The car features a dry-sump system with an oil tank located in the trunk. Despite the new engine, gearbox, and other modifications, the car only weighs 3,329 pounds (1.510 kg) – just 33 pounds (15 kg) more than the stock car. The E46 M3 even retains the original sub-frame, while the V-10 sits lower and further back, compared to the stock S54 engine.

The Autobahn Run

All this sounds like a win-win situation and it shows in the acceleration figures. This time, we don’t have a lot of numbers, as they only measured the 100 to 200 km/h (62-124 mph) time, which was 6.90 seconds. According to the driver, the car has done a time of around 6.60 seconds for the same discipline. To put things in perspective, AutoTopNL tested a stock BMW E46 M3 Competition and managed to put down a 14.13-second time for the 100 to 200 km/h (62-124 mph) discipline. We even see the Beemer touching 186 mph (300 km/h) on the speedometer, without much effort.

What Was Sacrificed?

The car effectively became more than twice as quick as stock, but at what cost? None, actually. The driver praises the E46 M3 for feeling just as refined and as solid as the normal car, despite the heavy modifications.

Cars with engine swaps can sometimes be sketchy, depending on how well the build has been executed, which is why the driver and host had expressed some concerns prior to the review. “It could be quite an intimidating car to drive”, “it might feel weird”, it might feel way more hardcore than this”, is what the driver was thinking. Luckily for him, the car is well-sorted and that is the real art when it comes to modifying cars, especially when they are as coveted as a BMW E46 M3. Watch the video below to see the car in action and enjoy some epic V-10 "singing".