rennedescartes

Hi all -

I recently acquired a 2017 991.2 C2 7MT (which I love). The car is fantastic, and great fun to drive, but I have noticed a quirk that I'm not sure is expected or not.

I drive about 50/50 in Sport/Individual mode (I really like heel-toeing) and I've noticed that there is very noticeable rev hang in both sport and sport+ modes (I do have sport chrono). It's substantial enough that I don't rev match the upshifts very well in sport as I'm used to the much faster cadence of driving in 'normal' mode.

Is this something other people experience? I would have expected the opposite behavior, as the driving in normal mode *feels* a lot sportier without having to wait 2-3 seconds for revs to fall on the upshift. The car is still CPO for another year, so if it's a problem I'll take it to the dealer.

If this is something that other people experience - what do you all do? I can just slip the clutch a bit on the upshifts to get much smoother + faster shifts, but that feels like I'm just causing a lot of wear on the clutch... Perhaps this really doesn't hurt the clutch too much? I've only been driving manual for 3-4 years, and haven't had to slip the clutch on upshifts in my previous cars, so maybe I'm just overthinking it...

Let me know your thoughts!

enzotcat

Sport and Sport+ mode do rev-matched downshifts. In the 1st -> 2nd gear change, Sport/Sport+ mode will add an extra blip because the rev drop in 1st -> 2nd is rapid and this alleviates it. However, there is no "blip" in upshifting otherwise.

rennedescartes

Yes I realize they don't blip on the upshift - I'm talking about rev *hang*, the revs fall much slower in my car in sport/sport+ than they do in normal mode, so in order to match revs on the upshift I have to shift more slowly.

johnstoy

This is normal. In sport/sport+ when you first lift off the gas pedal the throttle-body actually stays open (power is cut through timing and fuel control) - this helps keeps the turbos spooled up (more airflow through the motor & turbos) so they are ready to boost more quickly after you shift.

If you listen carefully you can hear the effect when you just lift off the throttle with out clutching/shifting: there will be a slight delay before you hear engine braking kick in. The throttle body stays open for about a second to keep the turbos spinning.

rennedescartes

I see, this makes sense.
So what is the correct way to drive in, say, sport+? Should I slip the clutch slightly to pull the revs down? Or just let the clutch out quickly leading to a -slightly- rougher-but-faster shift?

johnstoy

Hard to say what is "correct", but when I'm having fun I go with the clutch-abusive "slight rougher but faster shift" that you mention. I might regret this one day if it breaks something... ($$$), but for now it's all fun.

911.

The car and clutch is designed to handle up to GTS power and tq levels. Either way you want to drive is fine. I personally shift out first gear a bit higher in the revs for a much smoother and faster ****. When the car is warming up, I do the slow method. I guess I've gotten to the point where I don't even notice it anymore and car doesn't feel any more unsettled.

johnstoy

The other thing to consider is that if you want to take advantage of this feature (turbos still 'spooled' - power is ready to go in the next gear) that you do need to shift quickly: before the throttle-body actually closes. Like 911 mentioned: it seems to be designed to be driven this way. YMMV.

Rich_Jenkins

I've never experienced any rev "hang" upshifting as mentioned in the OP in my '17 C2 7MT+SC. It might be I drive almost exclusively in Sport mode, but I dunno.

enzotcat

Ah yeah - you must be talking about the fact that sport+ keeps the turbo boost spooled up deliberately. Honestly, never bothered with slowing shifts for that, and I've never heard of anyone heel-toeing on an upshift. Downshift yeah, of course; upshift, not so much.