[F8green420]

If you hit the Sport button, the valves are always open. Your car will always start in V8 mode, all the time. 4 cyl mode is only to help highway MPG. The 6.4s have a way better exhaust manifold, that could be the difference in the sound.

sport mode only allows the valves to open to 70%

and to answer ops question yes installing an active exhaust delete kit will give you the cold start sound at all times. however you dont need the delete kit for a 22 you can just wire/weld the active exhaust valves open and it does not throw any codes on the dash like the older model challengers do. nm i forogt you have to get z automotive active exhaust kit or similar product otherwise it will throw a code on the 5.7

 

[F8green420]

What only works on the SP’s. Please clarify. Thanks

yeh sorry i forogt that on the 5.7 you cant just weld/wire them open without throwing a dash code. you have to get the z automotive active exhaust kit or similar product otherwise it will throw a code on the 5.7

They stay open at 70% but are 100% open at WOT.

well of course but they are 100% open in normal/auto mode at wot as well