[SmoknTA]

Hi all! Thanks for taking the time. I love the cold start sound and volume on my ‘22 5.7/A8 T/A and I’m wondering if I install the Z Automotive kit will I always have that sound as if valves are wide opened. I do hear a difference in the sound between a 5.7 and 6.4 so would appreciate first hand experience with a 5.7 setup like mine.
Also, I don’t know if with a cold start all eight are working and then switch to 4 after warmed up. If that’s the case then I would expect a volume drop?

 

[Frank Julian]

although my 5.7L did not have the active exhaust, I did have the same system a 6.4L uses I just had the valves welded open in the exhaust. I can tell you comparing my 5.7L sound to a 6.4L, I think the 5.7L sounds better. I did a cam swap that eliminated the MDS and MDS only kicks in while driving, not idling.

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.

 

[Frank Julian]

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.

Yes but I think a stock 5.7L Sounds better than a stock 6.4L, I won't even get into mine with long tubes and highflow cats and a Whipple pushing an extra 2.9L of air through the motor.

 

[SmoknTA]

Yes but I think a stock 5.7L Sounds better than a stock 6.4L, I won't even get into mine with long tubes and highflow cats and a Whipple pushing an extra 2.9L of air through the motor.

Thanks! 5.7 is definitely different sound and I love it😄

 

[72/340]

I too think the 5.7 sounds better, more old school, the 6.4 sounds more European.

 

[SmoknTA]

I too think the 5.7 sounds better, more old school, the 6.4 sounds more European.

Agreed, it has a nice deep old school rumble.

 

[Too Fast]

Agreed, it has a nice deep old school rumble.

Agree with you too. When my wife pulls away down our street, the exhaust sounds about perfect. And I like my exhaust usually the louder the better, but her Challenger has such a deep sound, my hat is off to the engineers.

 

[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

 

[SmoknTA]

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.

Awesome! Thanks

 

[A Guy]

Actually that only works on the 2019+ Scat Packs, not the 5.7L

A Guy

 

[Too Fast]

I did not know that. So, the valves probably are only wide open with WOT?

 

[SmoknTA]

Actually that only works on the 2019+ Scat Packs, not the 5.7L

A Guy

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

 

[72/340]

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.

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

 

[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