NotABaller

Is this because I'm a terrible driver or sometimes the transmission actually doesn't upshift? This only occurs under WOT getting nearing the rev limit. If I don't shift early enough (say 6.5-7k) and "predict" it, then it just won't shift the first time and I hit the limiter around (7.5k?)for about a second before I try it again and it works.

BLKROKT

On a stock MCT, you need to hit that paddle 500rpm before redline or you'll bounce.

NotABaller

All shifts or mainly lower ones?

iownedu

Response time on MB paddles are trash, it's not you. Hence why I just run sport mode on the track.

NotABaller

Did a bunch of reading and tried the suggestions. Look like the solution is to put it into s+ and downshift to lowest gear it'll let me go. Then slam the pedal. Profit!!!

iownedu

Correct, and to get to the lowest gear quickest you can hold the downshift paddle.

NotABaller

Oh wow. Totally did not know this as I was downshifting shifting 3-4 times to drop from highway cruising gear to second gear for pulls. This is life changing information (my expected lifespan just reduced one week) thank you so much!!!

kjkidd21

...and to get it back to shifting on its own in S+, just hold the upshift (right) paddle.

Before my C63, I had an E9x M3 and the transmission on that car was PERFECT - you could literally run it all the way to redline and hit the paddle and it would shift instantly. With the C63, I exclusively use S+ mode when driving spirited and just downshift and upshift as needed. It really bugged me at first, but I've since gotten used to it. S+ adapts nicely to spirited driving - when the car realizes that you want to drive aggressively, it almost always keeps you in the right gear to maximize the TQ at any speed..

SuckaGDog

I've noticed if you press the upshift paddle as soon as the gauge cluster illuminates red and says "UP" you won't bounce off the rev limiter. If you're too slow at executing after it lights up red, then it won't be able to upshift in time. When the transmission upshifts itself in sport or sport plus it's very fast. The delay is only with the paddles. Boo. It won't be so bad when you get used to it. I came from E60 M5 which loved high revs and fast shifts at redline.

BLKROKT

It can be fixed with the Weistec TCU/VB upgrade, which isn't really a big deal to do. Shifts BANG now right when you want them.

NotABaller

Looking into the weistec tcu upgrade now. I've also noticed that the central display will turn all red and yell SHIFT SHIFT SHIFT pretty early in the rev range in first. Probably starting around 5.5k. So I guess I shouldn't ignore it and wait till 7k to shift.

The great part about all this is that we can just put it into S+ mode and not worry about missing shifts!!

SuckaGDog

Don't ignore it. If you shift right when those warnings come up it'll execute right at redline.

raphman

This.

Remember that 1st will rev the fastest and each consecutive gear will rev a little slower. The computer calculates this and, since it knows how quick the MCT will react, it'll tell you precisely when to tap gear + so that shifts happen right at redline.