Project E46 M3: Part 14 – Short shift kit and lightweight clutch and flywheel testing!!

Project E46 M3: Part 14 – Short Shift Kit and Lightweight Clutch Testing!

by Pablo Mazlumian

In our last installment we featured the Clutch Masters FX400 single disc clutch with aluminum flywheel. While some enthusiasts may be a little apprehensive about using an aluminum flywheel (versus a steel one, or simply retaining the dual mass unit), I’ve had no issues in recent years running a similar setup from Clutch Masters in my last E36 M3. That said, I do know what people are referring to when it comes to clutch rattle, having had aluminum flywheels in two other E36 M3s. A couple of those units did make significant noise at idle or low RPM, especially with the AC turned on. This one from Clutch Masters, however, hasn’t been a problem. But more on that later—let’s finish the job, shall we?

To bring some of us up to speed, here’s another glimpse of the Clutch Masters FX400 with 11-lb aluminum flywheel we featured in Part 13. In this installment we’ll actually have it tested with dyno figures and all (on page 5)!

Even though this was my first attempt at doing a clutch job in an E46 M3, it wasn’t too much of a problem. Perhaps my situation was a little better given the easy access to the starter bolts with the quick removal of the Castro Motorsports intake manifold, which only takes a handful of minutes to perform. You can read more about the installataion, and the amount of weight this clutch upgrade saved us, in Part 13.

One way to see how the clutch and flywheel combo makes a difference is to dyno test it. This test is something you don’t see often, though. In order to have a proper and more reliable dyno test, there should be a new baseline established if the previous runs were performed a while ago, or if the weather has changed. After all, different brands of gasoline or oil can make a significant difference, and the weather change always fudges the numbers.

I’ve always found it best to start with a new basline, and in our case I’m glad we did. Given that this test was conducted in the heat of August, it didn’t surprise me to see less horsepower than what the car tested two winters ago. Had we not baseline-tested again, I’m sure we could have otherwise convinced our readers that this clutch and flywheel combination produced a loss in power, when this shouldn’t be the case. Still, 311whp @ 7900 RPM and 255 lb-ft @ 4200 RPM is pretty stout for this 3.2-liter.

It should be noted these are SAE numbers, whereas we used to use STD correction with this project (the new Dynojet Winpep8 program limits us to SAE). In any case, notice how the engine sustains up to 234 lb-ft of torque before dropping, and all the way up to 6700 RPM. That’s how these cars make good power for a 3.2-liter six-cylinder in the top end. It’s a great combo of maintaining cylinder pressure, while providing excellent flow characteristics.

With the transmission dropped, there are a few “while you’re at it” options. As discussed in Part 13, one is to replace the rear main seal (because the clutch itself was off), and another can be to add a short shift kit. I’ve had great success with UUC Motorwerks in the past with my E36 M3s, so I was confident using their product again. This is the EVO3 kit with optional DSSR. Every piece has been well thought out by UUC—even those two black little bushings on the bottom right. We’ll have more on that in a bit.