Hey everyone,
My original 2003 MCS (192k miles) clutch is finally on its last leg, so I need to replace it soon. While I’m at it, I’m planning to swap in a later gearbox for the shorter gears and add an aftermarket LSD.
For context, my current mods are: 17% pulley, GRS intercooler, 550cc injectors, and a Scorpion manifold (no cat). I’ll probably add cams later too.
The car does a bit of everything, form desert track days, canyon runs around LA, and quick errands around the neighborhood.

I have a few questions and would really appreciate some guidance : )

1) Does the later BKE gearbox fit plug-and-play on my 2003 MCS?

2) According to RealOEM, the clutch part number changed between model years: 21207551383 is listed for MCS up to June 2004, while 21207551384 is for later models. If I change the gearbox, which clutch would I order?

3) Which other parts should I replace when doing the clutch? Anything in the clutch control system?

4) Lastly, any clutch recommendations? I was originally considering the Valeo SMF conversion ($450), but I’ve read it might not handle the torque well with my mods. Alternatively, I’m looking at a new LUK DMF ($250) and LUK clutch ($100). What would you recommend?

Thanks,
Tom

 

The clutch was upgraded to handle the extra power of the JCW GP model- but the parts are interchangeable with earlier models.
If your car is a daily driver, I would recommend Luk. But that's just my opinion.

Even though the later gearboxes are geared lower, the gears are actually spaced further apart (it's lower in the lower gears, but 6th gear is roughly the same). I would argue the earlier gearboxes would be better suited for track days, closer gear spacing is generally better for racing.

 

Id you want LSD you could also opt for a BKL gearbox, which is the BKE with factory fitted LSD. That will probably be a lot cheaper then getting a Quaife lsd diff.
My R53 has the BKL and I'm happy with it but I don't have any mods nor do I do track days. It's just my daily.

I also have the Valeo SMF kit and I wouldn't install it again to be honest. It makes quite a lot of gear clatter. Though the clutch is much lighter compared to the LUK which is nice during rush hour.

 

The Valeo single-mass handles my R53's 220hp easily for daily driving (sometimes spirited) and the light clutch feel is great for traffic. But, I wouldn't use it for even an occasional track car, especially if you're going to fit an LSD. Same goes for the LUK. Stage 1 minimum for a daily; Stage 2 for track use. More expensive for sure but you'll appreciate not having to replace it again after 10k miles.