Catback is mainly for sound as the OEM system is large enough to handle good power. Only really need it when chasing bigger numbers, but I'm sure you will find some way to disagree.
On my 3.0 I already took out 80lbs by:
1. Drivers seat swap to Sparco race seat with six point harness (saved 26lbs)
2. Powertex lightweight Lithium battery (saved 48.8lbs)
3. Took the rear diff harmonic weight thingie off (saved 5.2lbs)
That's just the easy stuff.
If it's your first track event ever:
1. Make sure you have an instructor.
2. Bring lots of water.
3. Make sure you eat.
4. Make sure all your car fluids are pretty fresh, with a 2023, you are probably just fine.
5. Pace yourself.
6. Have fun.
Ignore anyone that states matter of factly that you...
Take that tone with BMW, who designed it that way, not me.
I love how you ask questions and even when you get 100% factual answers, you still disagree. Why even ask questions?
It happens when the factory creates them and then installs them in Graz, Austria.
It's for clearance. Not the first car to have this and won't be the last.
You're an engineer, I'm sure you can compute how many of your rubber gaskets could still flow through those parts. RPM, rubber per...
I've used both 275/40/18 CRS V2 and 295/35/18 CRS V2 although it's not really a fair comparison as the 295 CRS are wayyyy too wide for 18x10.5 wheels. I am solving that this year by going to 18x11.
Now, things that don't depend on the wheel width. I could feel the weight and drag difference for...