Car (2007 E63) felt slower after dealer ECU/TCU flash?
Problem is the car actually felt slower than before, right after the re-flash I took the car to a muffler shop to have the resonator delete done (replace with a X-pipe but all 4 cats are still in place). I dont think the X pipe will make the car slower?
A few theory behind this:
1) Car is still adapting to the resonator delete (a little less back pressure than before and I lost some back pressure).
2) The new ECU/TCU update is a "smoother" version that eliminates the jerkiness in shifting and is somewhat less powerful that what was on the car
3) The previouss owner had a tune on the car that I was not aware of.
What do you guys think?
Last edited by box986; May 1, 2010 at 02:10 PM.
Problem is the car actually felt slower than before, right after the re-flash I took the car to a muffler shop to have the resonator delete done (replace with a X-pipe but all 4 cats are still in place). I dont think the X pipe will make the car slower?
A few theory behind this:
1) Car is still adapting to the resonator delete (a little less back pressure than before and I lost some back pressure).
2) The new ECU/TCU update is a "smoother" version that eliminates the jerkiness in shifting and is somewhat less powerful that what was on the car
3) The previouss owner had a tune on the car that I was not aware of.
What do you guys think?

4) Although the car feels slower and smoother, it could actually still be faster.
I've seen so many instances where someone gets a tune, feels that the car is much faster, but then when he dynos or tracks the car, the car performs a lot worse and vise versa.
I would take the car to a decent dyno shop and have her dynoed or better yet, take it to a track and see where she stands. Then, we can start the process of elimination in diagnosing the problem.



