[M3coupe]

Just looking for some insight. Driving 335is today. 95degrees out with myself 165lbs, brother 210lbs, and nephew 165lbs, and daughter 37 lbs. Going about 50 mph, AC on, I needed to pass so went WOT (pedal to the floor). Felt car downshift and rpm's shoot to 7k but the car did barely began to accelerate. After 2sec at 7k I let off the gas.
Wondering If I just didn't give it long enough to engage or if with all the weight in the car and over boost kicking in the clutch didn't grab?
Car is 2011, with 15k miles. DCT transmission, sport mode on. Is this all in my head?

[bigdnno98]

Sounds like classic clutch slippage but I've never personally felt it in a DCT. I'd def have dealer look at it. I almost pulled the trigger on a 135i DCT last month. Only reason I didn't was the $1700 clutch disk upgrade. No thanks. DCT will only hold around 420 tq to the wheels from what I've read. You want more, you have to upgrade clutch disks for around $1700 just parts. Prob $2500 with labor.

[M3coupe]

If this was the clutch slipping? Was it the extra weight in the car? Meaning with just me in the vehicle is this something I would have to worry about with only 15k miles. Makes me second guess getting a tune as more power than what I have would only cause it to happen more often.

Of course this is I the clutch was slipping. Also, if I took to the dealer how would they test?

[M3coupe]

Anyone else have any ideas? 335is completely stock

[tagon]

Did you try doing the same thing with just you in the car? If so did it slip then? I have 17k mi on mine and the only thing i feel slipping is my tires when i go WOT.

[benzy89]

This is a known problem with the high HP supercharged M3s who have DCT trans. Especially with our turbo'd engines, we're usually exceeding (or right up on the limit) of the TQ rating on the trans

Look into SSP Performance DCT Clutch Upgrades
http://www.sspperformance.com/sub-ca...ransmission--/

[e90335imike]

Originally Posted by benzy89

This is a known problem with the high HP supercharged M3s who have DCT trans. Especially with our turbo'd engines, we're usually exceeding (or right up on the limit) of the TQ rating on the trans

Look into SSP Performance DCT Clutch Upgrades
http://www.sspperformance.com/sub-ca...ransmission--/

Originally Posted by M3coupe

Anyone else have any ideas? 335is completely stock

This shouldn't happen at stock power levels. Dealer it, why have the forum guess when you're stock and in warranty?

[benzy89]

Originally Posted by e90335imike

This shouldn't happen at stock power levels. Dealer it, why have the forum guess when you're stock and in warranty?

Chill -- Forgot that you provided the "perfect solution"

Since the car is completely stock & you've added a bunch of weight, the car isn't going to feel as fast as when you're in the car alone. If the car shifts & drives fine when you're in it alone + there's no transmission fault codes, the car is fine & it's just your mind playing tricks

[BQTuning]

Originally Posted by M3coupe

Just looking for some insight. Driving 335is today. 95degrees out with myself 165lbs, brother 210lbs, and nephew 165lbs, and daughter 37 lbs. Going about 50 mph, AC on, I needed to pass so went WOT (pedal to the floor). Felt car downshift and rpm's shoot to 7k but the car did barely began to accelerate. After 2sec at 7k I let off the gas.
Wondering If I just didn't give it long enough to engage or if with all the weight in the car and over boost kicking in the clutch didn't grab?
Car is 2011, with 15k miles. DCT transmission, sport mode on. Is this all in my head?

No that was not a clutch slip. Sound like the mechatronic controller did not fully apply the clutch for some reason.

1) Sounds like you had the car in regular Drive mode w/sport enabled

2) At 7k RPMs there is no power to be felt with all that weight making it worse when the clutch was being applied

[BQTuning]

Originally Posted by bigdnno98

Sounds like classic clutch slippage but I've never personally felt it in a DCT. I'd def have dealer look at it. I almost pulled the trigger on a 135i DCT last month. Only reason I didn't was the $1700 clutch disk upgrade. No thanks.

And you will go through replacing more clutches, costing more, within a period of time on a MT before you will need to replace a DCT clutch pack again.

Originally Posted by bigdnno98

DCT will only hold around 420 tq to the wheels from what I've read. You want more, you have to upgrade clutch disks for around $1700 just parts. Prob $2500 with labor.

No one knows the exact whp or wtq limitation, it is all conjecture at this point. Also labor will not cost you that much either. On the books it is 6 hours to remove and install a DCT. There is 2 hours to open the DCT, replace the clutches, and then reseal it. So you are looking at 8-9 hours of labor. So you should not be paying anything more than $1300-1500 in labor for the entire job

[BQTuning]

Originally Posted by e90335imike

...This shouldn't happen at stock power levels. Dealer it, why have the forum guess when you're stock and in warranty?

Boost starts to run out of breath after 5500 rpms, so after hiting the kick down the RPMs flingshot to 7k RPM with all that weight he is not going to move anywhere.

Also, I also learned the Mechatronic on the DCT plays a big roll of how much preasure to apply to the clutch. The hotter it is clutch pressure is reduced whereas the cooler or colder it is more pressure is applied.

[bigdnno98]

Originally Posted by BuraQ

And you will go through replacing more clutches, costing more, within a period of time on a MT before you will need to replace a DCT clutch pack again.

No one knows the exact whp or wtq limitation, it is all conjecture at this point. Also labor will not cost you that much either. On the books it is 6 hours to remove and install a DCT. There is 2 hours to open the DCT, replace the clutches, and then reseal it. So you are looking at 8-9 hours of labor. So you should not be paying anything more than $1300-1500 in labor for the entire job

I said $2500 with labor. I factored in $800 for labor at an Indy. I've already priced it so I know how much it costs.

[BQTuning]

Originally Posted by bigdnno98

I said $2500 with labor. I factored in $800 for labor at an Indy. I've already priced it so I know how much it costs.

Got it, misunderstood the $2500 to be labor cost exclusively

[pavo335]

the benefit of a sequential gearbox is fast changes the downfall is needing a gear that is not next to the current gear. sounds like the dct was hunting for the right gear and got stuck, it happens from time to time, thats why you have paddles use them you wont be dissapointed

[M3coupe]

You guys are great. thanks for the insight.
I just get more and more questions with every response.
I too think this is just in my head and that I need to research how the DCT works as the number of tuned vehicle post and cars well over the HP/Tq of the 335is stock on this forum are 1000 to 1 vs those seemingly with Clutch issues.

One more question though. In Drive D mode w/ or /without sport shouldn't I be able to just step on it (WOT) to get up and go/pass regardless of the occupants or anything else.

Anyone else know of any similar post to this that I didn't find in my search that may have additional info.

[BQTuning]

Originally Posted by M3coupe

One more question though. In Drive D mode w/ or /without sport shouldn't I be able to just step on it (WOT) to get up and go/pass regardless of the occupants or anything else.

There are two things you have to learn about your car:

1) Predicting the DME
2) Understanding the DCT mechatronic's logic

You have to know how, and when to do something based on what you know the DME allows or doesnt allow

Based on temps, driving mode, weight, RPM, and speed, will determine how your transmission will react to your commands

Its like trying to learning two personalities at the same time.

• D mode (pimp mode), with Sport disabled, is for regular commute driving, gas saver, cruising, softer throttle response
  
• D Mode with Sport enabled adds faster "auto" shifting, trimmed exhaust sound, agressive trottle response
  
• S Mode with Sport disabled, more agressive throttle response, louder exhaust grumble,
  
• S Mode with Sport enabled adds faster "auto" shifting, trimmed exhaust sound
  
• M Mode with Sport disabled, louder exhaust sound, more agressive throttle response, less DME intervention,
  
• M Mode with Sport enable adds, sharper exhaust sound, faster "demanded" shifting, sooner agressive throttle reponse

So if I was in your shoes and I wanted immediate power, I would throw the car into M mode, with Sport Enabled, and gear down to where I want my RPMs to be held them punch it.

If the RPMs are too low when trying to floor it then the DME will downshift. To avoid this manually gear down yourself.