Surge on takeoff

[TX_Carguy]

I have replaced the belt, rollers, and sliders but I still have a violent serge on take off, Thoughts?

 

[RollaCosta]

Do you have stock ECU? It might help if you reset adaptations, given it was not reprogrammed.
what about your exhaust and oxygen sensor?

 

[RollaCosta]

It could also be clutch worn, not engaging at lower rpms. How many miles has it run?
Non-stock clutch springs can do this too, Malossi red for example.
stock ones are white

 

[TX_Carguy]

Do you have stock ECU? It might help if you reset adaptations, given it was not reprogrammed.
what about your exhaust and oxygen sensor?

I believe it to all be original equipment.

 

[TX_Carguy]

It could also be clutch worn, not engaging at lower rpms. How many miles has it run?
Non-stock clutch springs can do this too, Malossi red for example.
stock ones are white

Interesting, I didn't check the clutch. It is a 2013 with 13,000 miles on it.

 

[RollaCosta]

Mine has started slipping and vibrating at start after 20000km, and was replaced by Dr.Pulley by 35000, huge difference.
If you read 2016 BMW PR release with focus, they spell “softer lining in the clutch”. I would not trust to buy another from BMW.
Just speculating, but it could also be your clutch bell is worn out by previous “harder lining”, definitely check everything incl. inner diameter. Malossi’s white springs (“T” of the three in the set) should work if you have all else is good but non-stock springs installed.