[youssef123452002]

I have a 2016 435i xdrive auto with 160K KM now , I got the car about a year ago , car had mppk and mpe from day one I believe . I added a dinantronics stage 1 on top of mppk , car was fast. from time to time I would feel slight decline of torque on low speeds. I thought there was a lag because of the piggy tune. car was smooth and tranny was fast on sport plus as normal.
so I decided to move on to bootmod stage 2 with a charge pipe and catted downpipe.
car felt fast of course but there was a slight hesitation on high speed , and sometimes you feel a slight loss of power in low speeds.
I never expected it to be tranny slippage.

I came across the bm3 TCU flash and was hesitant to do it in the beginning.
last week decided to try it , I was blown away. what a difference in power
I did not expect or thought that my tranny was slipping that much.
the power difference is huge and noticeable. at least with my car

this car is properly fast now , it almost feels as fast as the f80 I used to have
For anyone with high mileage modded xdrive 35 with ZF8HP45 , my opinion you have to give this a shot if you are having similar issues.
may be it's only my car , but these are my impressions. And I could not find enough posts about the TCU flash specially with Xdrive as it is a fairly new tune.

[thejeremyman9]

Questions:

1. Has the trans ever had the pan/filter/fluid changed in the life of the car?

2. What makes you think the trans was slipping? Are you sure you were not hitting toque limits?

3. Are you running stage 2 without a IC?

4. Post logs?

[youssef123452002]

Originally Posted by thejeremyman9

Questions:

1. Has the trans ever had the pan/filter/fluid changed in the life of the car?

2. What makes you think the trans was slipping? Are you sure you were not hitting toque limits?

3. Are you running stage 2 without a IC?

4. Post logs?

1- I did the pan filter fluid at 150K , I would assume it has never been done before.

2-you might be right , but I would doubt it because it was doing the same with the dinantronics and mppk which isn't that much , . Also what happens exactly when the torque limit is hit ? Does the ecu cut power ? And what is the torque limit ?

3- I live in canada and summer is almost over this year , I will get one before next summer. I am not that worried it's pretty cold in here most of the year. And when it's warm I don't go crazy either

4- unfortunately I don't have any logs . I don't have enough time. May be I can try to do some.

But one thing I am sure of , the difference is huge with the car after that TCU flash.
Again it might only be my car.

[thejeremyman9]

Originally Posted by youssef123452002

1- I did the pan filter fluid at 150K , I would assume it has never been done before.

2-you might be right , but I would doubt it because it was doing the same with the dinantronics and mppk which isn't that much , . Also what happens exactly when the torque limit is hit ? Does the ecu cut power ? And what is the torque limit ?

3- I live in canada and summer is almost over this year , I will get one before next summer. I am not that worried it's pretty cold in here most of the year. And when it's warm I don't go crazy either

4- unfortunately I don't have any logs . I don't have enough time. May be I can try to do some.

But one thing I am sure of , the difference is huge with the car after that TCU flash.
Again it might only be my car.

Torque limits are mostly only an issue in 3rd/6th gear. And yes, the DME will limit power so as to not exceed the limits. Trans flashes like XHP and BM3 raise said limits so that you don't hit them and dont have the limited power in those gears. I just think its very unlikely the trans was actually slipping... more likely than not it was something else.

Anyways, glad it worked out for you. Logs are a good idea, even if done only intermittently, to make sure everything looks OK.

[youssef123452002]

Originally Posted by thejeremyman9

Torque limits are mostly only an issue in 3rd/6th gear. And yes, the DME will limit power so as to not exceed the limits. Trans flashes like XHP and BM3 raise said limits so that you don't hit them and dont have the limited power in those gears. I just think its very unlikely the trans was actually slipping... more likely than not it was something else.

Anyways, glad it worked out for you. Logs are a good idea, even if done only intermittently, to make sure everything looks OK.

You might be right , thanks for the insight