Turbo Lag

[patricksr]

Hi Everyone

I have had my 135is with DCT since April and the turbo lag (slight hesitation) at take off from a traffic light or stop sign is driving me crazy. It is better if I press the Sport button and even better if I drive it in S or M but in D it is maddening. I have read that a JB4 tune will eliminate this...is this true? Any other ideas?

Thanks in advance.

[Simsims]

reset your throttle/gas pedal

[cheshirecat79]

IMO this isn't turbo lag as much as DCT stutter. Read this thread and see if any of it sounds familiar.

http://www.1addicts.com/forums/showthread.php?t=675318

[Dackelone]

BMW has been rolling out a detune for the 135i's. Mostly because people have been complaining(ie lemon-ing) the cars for noisy wastegate, injector and stalling or poor idle. The only way to get your old rip roaring throttle response back is to opt for BMW's PPK2 sw flash. The Performance Power Kit. Or.. go aftermarket and get a tune. Some say the piggy back tunes work, but I would go with a real flash tune (like Giac, Cobb, Dinan, etc).

[patricksr]

@Simsims ...how do you reset the throttle?

[One3five]

I have 6MT and the catless downpipe totally eliminated that lag.

[alpinewhiteone]

i think it has more to do with your DCT as well. my car does the same and you get used to it.

[Simsims]

Originally Posted by patricksr

@Simsims ...how do you reset the throttle?

turn the car electricals on by pressing the power button once, without foot on the clutch/brake (ie, engine == off)

floor the gas pedal for like... 20s

start the car as you normally would


this doesn't always make a difference - all depend on your driving habit as the throttle adapts to your driving habit after a few stops and goes.

[135Pats]

Originally Posted by Dackelone

BMW has been rolling out a detune for the 135i's. Mostly because people have been complaining(ie lemon-ing) the cars for noisy wastegate, injector and stalling or poor idle. The only way to get your old rip roaring throttle response back is to opt for BMW's PPK2 sw flash. The Performance Power Kit. Or.. go aftermarket and get a tune. Some say the piggy back tunes work, but I would go with a real flash tune (like Giac, Cobb, Dinan, etc).

People are complaining about injector tick? Do they realize it’s a direct injection motor? Oye….

[Greenkirby21]

It's most likely your throttle. My 128i feels the same!

[3002 tii]

I test drove a dct few months back prior to my purchase and they definitely fixed it since then. Not sure if the cars been retuned but I know my July build doesn't have that delayed response issue

[Dackelone]

When I say BMW has neutered our cars by giving us a SW update... this is the thread I first saw on it...

BMW regarding 29.2 and lag?
http://www.e90post.com/forums/showthread.php?p=10205238

[Andrewcoja]

Originally Posted by 135Pats

People are complaining about injector tick? Do they realize it’s a direct injection motor? Oye….

Some people just see a brand name and think "That's the best one, I need it." And buy whatever they can afford out of the line up then complain about everything that makes the car not a boring lexus or buick sedan that they should have bought.

[IEDEI]

Originally Posted by Dackelone

BMW has been rolling out a detune for the 135i's. Mostly because people have been complaining(ie lemon-ing) the cars for noisy wastegate, injector and stalling or poor idle. The only way to get your old rip roaring throttle response back is to opt for BMW's PPK2 sw flash. The Performance Power Kit. Or.. go aftermarket and get a tune. Some say the piggy back tunes work, but I would go with a real flash tune (like Giac, Cobb, Dinan, etc).

the 135is comes with the PPK2 kit installed.

FWIW....I have no such issues but my car is manual. Could this be a DCT software issue?

[CAVU]

Originally Posted by IEDEI

the 135is comes with the PPK2 kit installed.

FWIW....I have no such issues but my car is manual. Could this be a DCT software issue?

My 135is has the DCT. I have experienced brief hesitation from a stop, but I believe it is related to the DCT and not the throttle, and certainly not turbo lag.

I'll probably get flamed by those who are more technically savvy on technical topics, but when I think about the programming and mapping that would need to go into the DCT, it isn't hard to imagine scenarios where the DCT isn't able to predict with 100% accuracy your immediate intentions. "D" plus foot off the brake doesn't necessarily mean for certain that your next move will be to nail the accelerator. Mechanically speaking, I don't know if sitting at a light in "D" with the brake applied is telling the DCT to be in neutral, or just to keep the clutch disengaged. If you take your foot off the brake, does the clutch immediately engage first gear, or does the DCT wait for a signal that you have depressed the gas pedal? Who knows.

All I know is that sometimes the DCT gets confused. Not a deal breaker. Just another good reason to get the 6MT.

[dm135is]

As a single data point . . . I test drove a 135i DCT before buying my 135i 6MT. The DCT I drove had very noticeable lag - at one point I slowed down then sped up to go through an intersection, and it just bogged down hugely and dangerously in the middle of the intersection before it picked up and drove off. I bought a 6MT 135i and it had noticeable turbo lag but not as bad as the DCT which I assume had both turbo and transmission lag. I got Dinan Stage 2 software installed on my 6MT at 5K miles, and the turbo lag is all but gone, I notice it very rarely and when I do it's already past. If you have a DCT and the lag is bothersome, recommend you take it to the dealer and see if they have an updated software flash to address it. FWIW, HTH.

[MZWIE]

DCT inherently have this wierd lag feeling. It's all about how the system "feathers" the clutch.

I recently test drove a 2013 Cayman whihch had the same feeling. Subsequenlty some one asked me to drive their 2013 Focus (which has a DCT type tranny) and it felt the same way.

In earlier SMG cars it was really noticeable. Bottom lilne is the DCT's are great at speed for fast shifting but are a bit disconcertting when power from a stop.

[gman36]

Originally Posted by e34m5

DCT inherently have this wierd lag feeling. It's all about how the system "feathers" the clutch.

I recently test drove a 2013 Cayman whihch had the same feeling. Subsequenlty some one asked me to drive their 2013 Focus (which has a DCT type tranny) and it felt the same way.

In earlier SMG cars it was really noticeable. Bottom lilne is the DCT's are great at speed for fast shifting but are a bit disconcertting when power from a stop.

An e92 M3 with dct has an awesome transmission feel when moving from a stop. Which is weird that the 135 has such a bad lag when the transmissions are the same units.

[cheshirecat79]

Originally Posted by gman36

An e92 M3 with dct has an awesome transmission feel when moving from a stop. Which is weird that the 135 has such a bad lag when the transmissions are the same units.

It was a software issue. The problem seems to have been fixed with the latest update.

[1GrayBulldog]

If anyone is having this issue I definitely suggest resetting the throttle. I stepped into a 2013 135i over the weekend that had been on the dealer's lot for a while, and there was a substantial throttle input lag when accelerating from idle which was completely solved by the reset.

[gman36]

Originally Posted by cheshirecat79

It was a software issue. The problem seems to have been fixed with the latest update.

When was the update released? I would say bmw tried fixing mine about 4 months ago but it still lags

[MightyMouseTech]

Originally Posted by 1GrayBulldog

If anyone is having this issue I definitely suggest resetting the throttle. I stepped into a 2013 135i over the weekend that had been on the dealer's lot for a while, and there was a substantial throttle input lag when accelerating from idle which was completely solved by the reset.

And how do you reset it?