[wtfbrah]

So help me out here, smart car people. In a direct comparison today, I took the M235i out right after the Cayman.

The one thing I noticed that annoyed me about the M235i was this lurch. I drove the car in Sport+ with TCS off and manual mode on, using the paddle shifters. I found that if I accelerated quickly, to, say, 5k RPM and then upshifted while keeping my foot on the gas, the car would lurch noticeably, backwards and then forwards.

Now I am not privvy with transmissions, clutches, gear ratios, etc, but this did not happen with the Cayman. If I had to take a wild guess, I would say it's because the Cayman has a DCT and shifts quicker. But...

I also noticed that if I tapped the throttle a little / pushed harder right before or as I shifted, that lurch was less noticeable or gone. I also noticed that when not in manual mode, that lurch was gone. So now I'm thinking rev-matching/timing of the throttle and shifting.

So what is it, folks? Am I a bad driver, or is it the car's delay?

Edit: After reading more I'm thinking it might be an issue with this specific car - I mean, it is a dealer car which has probably been driven hard and not broken in, could this cause the aforementioned issue? Seemed to be mostly 2nd-3rd

[Face]

I think (I hope) this is programmed into the car. Mine does the same thing...

It hasn't been abused, but it lived it's first few miles on the autobahn...so....

[wtfbrah]

Originally Posted by Face

I think (I hope) this is programmed into the car. Mine does the same thing...

It hasn't been abused, but it lived it's first few miles on the autobahn...so....

damn, i was kind of hoping it was a problem with the car or down to bad driving on my part. it's kind of annoying.

[allthatisntnow]

Never noticed this on mine i must say. Perhaps the 8AT needs resetting/reprogramming as its probably due to how its adapted to driving style. You will notice with pdk/dct there is no interruption to the flow of power as thats the whole point of dual clutch. The 8AT is remarkably close in my experience though.

[wtfbrah]

Originally Posted by allthatisntnow

Never noticed this on mine i must say. Perhaps the 8AT needs resetting/reprogramming as its probably due to how its adapted to driving style. You will notice with pdk/dct there is no interruption to the flow of power as thats the whole point of dual clutch. The 8AT is remarkably close in my experience though.

ah, so it adapts to how you drive?

[nike001]

It's the transmission shifting...?

It's a sport transmission and since you had it in sports mode, it didn't care that you felt the actual shift. Put it in comfort mode and it'll go away.

[allthatisntnow]

Originally Posted by wtfbrah

ah, so it adapts to how you drive?

Yes, it learns the users driving style and adapts its shift patterns to suit. I believe it has three different shift speeds to choose from and, like Porsche in sport plus, a "rough" sporty gear shift that delivers a bit of a thump is selected, although nowhere near as abrupt as the PDK. Perhaps this is the sensation you're experiencing. There is a method to resetting adaptation lurking somewhere on the 3 series forums, but i think people have had mixed success. Best way is to get dealer to do it if you think it is operating abnormally. Also it won't perform optimally until its up to operating temp. it takes much longer than the engine to reach it under normal driving, hence why the 1-2 shift jerkiness is often complained about heading off after a cold start. It can be up to 30 minutes of driving before it starts plateauing I've noticed with the JB4 app monitoring vs 5-10 for engine oil. Normal driving is about 60C, sporty can be around 85C.
The zf8 is a very capable box considering its primary goal is comfort on the road. I still believe it handles its sportier duties rather admirably.

[morphomeman]

The solution is simple: if you drive like a lunatic, the transmission will respond in the same manner.

[wtfbrah]

How is upshifting at 5k rpm with foot on the gas "driving like a lunatic"

[Dylan86]

Originally Posted by wtfbrah

How is upshifting at 5k rpm with foot on the gas "driving like a lunatic"

I think it was just a blanket statement... It will adapt to any driving style, really. Same as most modern auto's and dual clutch gearboxes. If you beat on it more than not, it will stay in a "sport" mode for much longer until you sustain an average speed for a certain time frame.

I hate driving my mothers Allroad because she never drives it hard, and the transmission is very slug'ish in responding to kick downs etc. After I drove it for a week, it had a adjusted to my driving style and she started complaining about rough shifts and the car holding gears longer than it was before lol, a week later it was fine after she got back into it and drove it her way.

[nike001]

Originally Posted by wtfbrah

How is upshifting at 5k rpm with foot on the gas "driving like a lunatic"

Moderate throttle and shifting at 5k is aggressively driving. You're telling the car you want to go, so it's going. What's the issue?

It's not going to comfortably change gears and reduce shift time by 10 years because you don't want to feel the gear change. You're telling the car to go so it's slamming gears; Get used to it.

You want smooth get a DCT or CVT.

/thread