At a Glance
Estimated time: 5 hours
Cylinder head rebuild: $300
Umnitza V1 Mirror: $400
With the amount of track and performance testing Project M3 has undergone, it's safe to say I've tested its limits to a greater degree than most other owners of AA Turbo-equipped M3s. I'm now on the second engine block, fourth cylinder head, second turbo, third transmission and second clutch disc. Okay, it sounds a lot worse than it really has been. In truth, the only parts that actually broke were one head gasket off the factory 3-liter (my fault for turning up the boost and not the octane) and one transmission. We haven't quite figured out what happened to that tranny.
The current turbo is a slightly different unit from the original AA Stage 2 unit. Last year, I moved up to AA's Stage 3 turbo when evosport took out the stock 3-liter in place for a built-up, low-compression 3.2-liter with forged internals, even though the condition of the stock 3-liter block was fine. I was just going after longevity at that point.
So what about the four-cylinder heads? Back when the car was normally aspirated, the cylinder head was rebuilt after testing the Schrick camshafts in order to prepare it for AA turbo power, especially since the valve guides were a little shot. When that 3-liter was ditched, I was on my second cylinder head-one from a 325is-which came with the 3.2 block from Bavarian Engine already ported and polished. Suspecting the excessive oil consumption at the time was coming from this cylinder head's valve guides, I had it rebuilt once again by Bavarian Engine, only to have the same problem: a quart of oil gone every 400 miles, and it was three times worse on the track.
"Forget it," I said. "Let's get the old cylinder head back on." After its first build-up, it didn't lead to excessive oil consumption when it was turbocharged with AA's Stage 2 system.
The original cylinder head had been at evosport all this time, and I gave Vadim Federovsky the "go" to get it rebuilt before bringing the car back in for the swap. During this time I made sure to get my hands on the hard-to-find BMP Design cutting ring head gasket, which I finally was able to hunt down.
After receiving word from evosport that the cylinder head was successfully freshened using my original stock parts, I brought in Project M3. Just to get a baseline, evosport dynoed the car at 15 psi, the boost I had been running with 95 octane (equivalent) fuel thanks to a Sunoco race gas mix.
I went into the test guessing that something might be wrong. The tires were getting plenty of grip under full boost in second gear, whereas previously I had been getting complete wheelspin. Maybe it was just me; the car still felt really fast, but I wasn't experiencing quite the rush I remembered.