Drag racing pushes a vehicle's powertrain to the limit. When running on the razor's edge, failures can be catastrophic when something goes wrong. Just watch what happens when this Honda-powered Toyota MR2 has its valve cover blow up on the strip.

The run starts fantastic. This car launches like a rocket down the track. Then, things go very wrong. From the starting line, the incident looks like a puff of white smoke. Things are much more dramatic from inside the vehicle's cabin because a spray of oil suddenly coats the rear window.

However, the driver doesn't realize anything is wrong because the engine is behind him. Naturally, he's paying attention to the track ahead. He’s unaware of a problem until a track official mentions a fire around the turbo and oil all over the track. When the racer finally looks at the rear window, his only response is a dejected, "Damnit."

Somehow, the engine developed enough crankcase pressure that the front of the valve cover exploded. The missing piece is big enough that the valve springs are easily visible.

The reason for the failure isn't apparent. There are large breather lines on the valve cover with tubes that run to a catch can in the cabin. However, a telemetry sensor on the engine shows 19.6 pounds of crankcase pressure. For context, a thread on the Honda-Tech forum references an engine having 0.5 to 1 pound of pressure while running 40 psi of turbo boost.

A separate issue with this run was that the transmission refused to enter fifth gear.

It's not all bad news, though. Before the valve cover exploded, the MR2 was having a fantastic run. The car set a new personal best for speed in the eighth mile at 156.58 miles per hour, which blew past the previous 149-mph top run. Despite not having fifth gear and the engine failing, the driver still managed to hustle through the quarter-mile in 7.6 seconds at 178.64 mph.

We reached out to the owner for more details about the cause of the failure and additional details about the car. His Instagram offers a bit more info, though.

 

The engine is a custom-built Honda K-Series four-cylinder engine with a billet block. A massive turbo feeds it boost. A custom exhaust with large-diameter pipes routes out of the panel between the taillights. The owner estimates the setup can make 2,000 horsepower when properly tuned.

If you want to see this MR2 running successfully, check out the video below. It covers the quarter-mile in 7.594 seconds at 192.38 mph.

 
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