DeerHunter

Can't argue with empirical data. I wonder if this is borne out with other cars featuring standard and dual-clutch transmission options.

bhk1004

Could be different gearing between pdk and the manual affecting acceleration times.

IMOA

It makes sense if you think about it. When you're shifting you're till carrying the same speed so in terms of time over distance you don't lose much, it's just the difference that the extra mph would get you over say half a second for each shift. Measurable but really quite small. In terms of trap speed however you've effectively been accelerating for an extra 1.5 so that gives you quite a bit more. It's the same reason that PDK makes a much bigger difference in 0-60/0-100 times than quarter mile times, in a 0-60 comparison a gear change is the equivalent of standing still whereas on a quarter mile it isn't.

Jenner

What's the latest update with the Stage 1 kit and/or 82mm TB issues and Cobb (or someone) fixing them?

Alan C.

Actually, when you shift you are decelerating for the duration of the shift.

rraustin

Having tracked a dual-clutch automatic for a few years, some observations:
Positive:
1. Depends on the shifts per lap, but faster shifts means being on power more
2. With dual-clutch you never lift when upshifting so more time spent at full power
3. Less mistakes with clutching, blipping, moving the shifter, can't accidently downshift at too high an rpm, results is more consistency. Of course if you are totally perfect with manual then this does not matter.....
4. Because shifts are very fast you can downshift to be at peak torque anywhere you need it. With manual you don't always have time so you stay in the higher gear which can be incrementally slower

Negative:
Dual-clutch weights 150 to 200 lbs more. The old drag racers rule of thumb says 150 extra pounds is like having 15 less horsepower

kitwetzler

Hi guys,

I was working with Mitch@cobb to identify an issue - I was getting the CEL every single second drive cycle after resetting. This meant the CEL suppression for too much airflow wasn't working properly. They finally found a bug in the code and are updating the Accessport with those maps. I had driven 200 miles so the TB adaptation had happened normally but was still getting CELs.

I'm pleased to report that the Stage 1 maps that I was sent now cure the issue - it was purely cosmetic as the car ran fine with the CEL but it was pretty annoying. Anyway, it's fixed now. I put 80 miles and 6 drive cycles on the car and no issues since. No need to use a PIWIS at all, just make sure you have the updated maps - email Cobb if you have an AP and are having issues with this setup.

Hope that helps someone. (I haven't experienced the throttle hang issue but I also haven't done any track driving yet.)

kitwetzler

The 991 PDK is listed at 3219 and the 991.2 7MT is 3175. Much less difference than you might think. (the 991 uses basically the same gearbox for PDK and manual, although the deltas are similar)

Jenner

This is great news!

So can I infer that Cobb fixed the CEL and removed the need for PIWIZ TB adaptation?

kitwetzler

They fixed the CEL and I don't really think there is a need for PIWIS adaptation. Even the dealer that I asked to do it told me it probably wouldn't change anything if the car ran right (which it did.)

What is likely is that you'll throw a CEL at some point while the car is adapting but it should go away on it's own, or stay away once it's been cleared. Or, you can pay for the forced adaptation.

bhk1004

More worried if the throttle hang issue has been figured out vs cels..

user1029

Agreed, I do rev match downshift a lot during my daily commute (I heel toe prior to right and left turns because racecar) with all my manual cars. I would not be good if the throttle hang left me careening toward incoming traffic or curb

ralphmusic

I am not sure what the bold section from the Quote means.

Does this mean that the Cobb tune just stops the CEL warning, or does it actually change the mapping to take advantage of the extra airflow?

cooperyau

I just ordered the race headers (without cats) so hopefully Cobb will be able to send the proper tune/map to both optimize the performance as well as eliminating any possible CEL. Has anyone recently worked with Cobb on similar header and tune?

kitwetzler

Both. The CEL warning suppression wasn't working, though, on my car.