I have a 2024 JCW F57.
I drive it "fairly hard" on the street, but would rarely take it over 5,000 rpm as I don't want to attract too much attention.
I will never track it.

I intend to get a stage one tune, if it can be done with the locked ECU. Otherwise I'll get the Dinan "Sport" piggyback unit. - The latter is set up primarily for low speed torque, so could be perfect and is really inexpensive as well.

I'll be upgrading the air intake as well, but not sure which unit yet.

Dinan recommends upgrading the exhaust, although that will only give minor gains. I live in NY State, where it's illegal to change an exhaust specifically in order to make it louder. (A very grey area!) so a valved exhaust is not possible. (And I wouldn't want it that loud, anyway.) I'm wondering if a more free-flowing exhaust, but still with a (larger) muffler and cat, would be worth considering.

The JCW already has a more free-flowing exhaust than the "S", I believe it has 2.75: diameter pipes, so the gains could be REALLY small. But could a larger cat / larger muffler help?
A deeper, throatier sound (just not significantly louder) might be worth it to me even if no real power gains, though I would NOT want a significant increase in the sound of the blow off valve. (Or bypass valve, whichever the mini has.)

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So, any thoughts or recommendations?


And a related question: I just installed the Dinan intake tube, to get rid of the intake resonator. Luckily, this very slightly improved the engine sound without any apparent (to me) increase in the valve popping noise. Exhaust systems, of course, come with and without a resonator. Does THAT resonator primarily dampen the popping noise, or does it affect the sound of the entire engine?

 

I added a 50mm Hybrid Turbo and a 3" Exhaust with 4: Double Tail Ends...needed it for the 50mm Hybrid Turbo.

Still planning on some upgrades for 2024 National Autocross and Pro Solo