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


To compare the difference in throw, I made a quick attempt at shooting before-and-after pictures from the same spot. Shown here is the transmission set to first gear. The stock one on the left, and our new UUC EVO3 on the right. It’s not a huge difference but you can see the UUC shifter stands slightly more upright, indicating that it’s a bit shorter throw to first, third, or fifth gears.
The real difference is noticed when pulling toward you, like when shifting to either second or fourth gears. By the pictures alone you can see that it’s a much shorter throw, and they make the 35% throw reduction claim by UUC believable. What we can’t quantify is the smoothness. Compared to the stock feel of this 67k mile M3—the difference is huge. The new shifter feels simply awesome. There is very little play, and you really feel each gear selection with each shift.
With everything buttoned up, we’re getting close to firing the car up. Our Colby Alcantara interior has been holding up nicely in Project M3.
The last thing we wanted to refresh in the driveline was our transmission bushings. This is a set of UUC Motorwerks “black” urethane bushings. This is where you get into the “every little bit counts” part. In theory, with firmer transmission bushings, you’re supposed to get a more direct power transfer from the transmission to the driveshaft by reducing flex at this junction. As a result, what upgrading transmission bushings can also do is reduce the chances of a mis-shift during spirited driving.
Here’s a comparison between a stock bushing on the left, and a UUC Motorwerks bushing on the right. The UUC unit is visually beefier, and much firmer to the touch. If you want something more aggressive for track use, UUC also sells two more levels of red urethane bushings for full-blown racers.
While I chose the black urethane bushings to keep vibrations dampened as much as possible, I also went a step further by sandwiching a thin slice of hose coupling between the chassis and transmission mount to further dampen vibration coming through the chassis. Yes, we know it’s loose but once it’s tightened you won’t be able to see it.

If a lightweight flywheel is going to help accelerate a car faster, a faster accelerating car should show some gains on the dyno. After all, we’re measuring horsepower to the wheels, not the engine. For dyno testing, we went to Modified by KC, which graciously let us use its Dynojet 424x dynamometer. Check out our results on the next page!


    1. hi and funny you should ask because–while I’ve sold the car a year ago to my father in CA (and I’m in KC)–he was actually sitting 5ft away from me when I saw this note so I was able to ask him and he says it’s relatively quiet. Can hear the chatter a bit during idle and of course if you turn the AC on but it’s not obnoxious or anything like that. thanks for reading!

    2. Hey I have the car currently! It’s pretty low key you won’t be able to tell while driving obviously, sometimes at idle although you here a lot of chatter lol. I personally think it’s amazing, after first gear it’s super forgiving. Per the clutch it’s very easy to set off, catch and rev match or heel toeing ( I guess part of that is owed to the flywheel too) and the stiffness imo is perfect. Short shifter is the cherry on top.

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