[VF-Engineering]

Originally Posted by SeanWRT

I like it m2 being treated differently and changes being made where there is room to improve.

Now if you don't mind I coming back with more questions on your OTS stage two tune:

1) Boost in the mid range and up top?

Boost on these cars is controlled by requested load.
What that means is that it's not a static value and will vary based on conditions.

For Stage ONE you will see 1.2bar at peak, tapering to 1.05bar.
For Stage TWO you will see 1.3bar at peak, tapering to 1.1bar.

2) Is DCT shifting strategy changed? If not, can you do that?
Shifting at 6500rpm would be the best for accelaration with a tune that cranks up boost
early on like yours at least from the dyno posted. Even on stock tune, m2 is proven to be
quicker with earlier shifts by our mutiple real world tests. Unfortunitely DCT likes
upshifting above 7000rpm at WOT.

The ECU software calibrations do not create any significant change in shift points.
There is correlation between the ECU and TCU which means that the torque levels
are properly communicated to the TCU, but the TCU itself it what controls shifting.
(we do not yet offer a TCU upgrade for the N55/DCT cars)

That being said, you are absolutely correct in the fact that these cars are quicker
when short shifting. For that purpose it's quite easy, and offers much more driver
control, to just grab the paddles and shift the car manually.

3) Does m2 stock burble remain intact or is it changed to GTS style?

We do increase the amount of overrun for the M2 with our software.
Keep in mind that not all of the "burble" on these N55 cars is related to the
overrun strategy. Much of it (especially on cars with aftermarket exhausts) comes
from the change in exhaust gas velocity which also produces similar "crackles" and
"pops".

I'll try to post up a video soon that is M2 specific, but here is an M235i which will be
very similar.

4) What's the AFR above 5500rpm? Concern is the stress on stock weak HPFP.

This is typically not information that we post publicly, but we also understand the
concern people seem to have over the fuel pump.

Stage TWO is calibrated to target .83 Lambda and will taper to around .81 by redline.
Based on all of our in-house dyno and on-road testing/data-logging, we are quite
comfortable with the fueling conditions for these cars at our boost and power levels.

If you look at the dyno plots we are not making gob loads of power up top where the
turbos and fuel system are over worked. We are though making generous low end
and mid-range power where we feel it's useful.

5) Does the catalyst heating circle on startup remain intact or is it removed like BM3?

We do not eliminate or turn off any emissions control functions with any of our
F-Series ECU Software.

6) I am assuming your tune is customizeable? What is the additional cost for a custom update on top of OTS?

Our tunes are actually not customizable.
We put a great deal of time, effort, energy, and resources into all of our software
development. The goal is to provide a pre-engineered - turn key software solution
that is optimized as Stage ONE or Stage TWO to be used with popular
hardware modifications.

The key word here is "optimize" versus "maximize". While there may still be room for
improvement with custom tuning to "maximize" your peak power, (albeit not as easily
accomplished as some would like to make it seem) the concept of "optimization" still
allows for some headroom based on conditional variations such as climate, fuel
quality, intended use, vehicle mileage, etc...