Thank you, Thunder. When I first heard this catalytic convertor comment, the exact same thought went thru my mind....heck the valve arrangement is within a foot of the tail pipe exit, so how can that affect the catalytic convertor, which is up stream from that. Thanks for confirming my guess!

 

Just wanted to add a final comment regarding pulling fuse number 15 on my 2021 R model....it is GREAT! Sure, we all get a roar when the car is started cold in a garage and then it quiets down...even when the "Loud" button is engaged. I just put about 120 miles on my car in one trip after I pulled the fuse. The car sounded great, you could hear that subtle burble as we cruised at 65-70 MPH, nothing IMO obnoxious and definitely better then the fuse #15 in and the Loud button "on". Took it to 90MPH and no drone or anything like that. Jumped on it and it was an explosion....but we expect that!
It's simple to do and my recommendation is to try it...you'll likely love it!

 

Try paddle shifting under hard excelleration with it out if you havn't, very cool.

 

Great news!! With the 15 fuse pulled out is the exhaust button always active?
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No, but the vacuum exhaust valves will remain wide open and never close after startup.

 

Ok, just pulled out the fuse n.15. Wow it is ANOTHER CAR! Beautiful exhaust sound. Incredible , it sound fantastic, wow , please everyone with the V8 have to try! I will never pull in the fuse, I just run 20 Kms in moderate RPM, never gone over 3.000 rpm but, not only more sound but better also. Thanks for this fantastic advice

 

Is that better than just switching dynamic mode on?

 

Is a lot better, I need to test the sound after 3.300 rpm , but the sound from 1000 to 3300 RPM is the best sound I have eve heard, you can hear the true growling V8 sound, sure one of the best

 

I am so glad to hear this! It solves my issue about always turning on dynamic mode as that was the main reason for wanting to do that. I don't want to have to constantly mess with hitting buttons every time I drive the car. Thanks for your feedback!

 

I believe Dynamic mode is more that just exhaust sound. Other things are tweaked including altering some of the tuning characteristics to make the car more aggressive..

 

Correct - engine, gear shift, steering and suspension are tweaked.

 

Ok , so can anyone hear the difference between 80% open (fuse intact,dynamic mode) versus 100%open (fuse pulled).
There seems it be no consensus depending on what thread you read
Is it OBVIOUS - noticible without trying
or subtle - there but you have to pay attention to notice.

 

Are you sure not pulling the fuse give you 80 % max valve opened and not 100%? That is with the fuse on do you think the exhaust valve never opens completely?

 

No real difference as far as I could tell on my V6S with switchable active exhaust, maybe a tiny bit louder, but of course it may be different on the V8.
I drove for about two weeks with fuse F15 pulled and then I put the fuse back in as there are times when I prefer to have the exhaust valves closed and a quieter exhaust, mainly when going up a steepish hill at around 1/3 throttle when it can be a little droney with the exhaust valves open, or when cruising down the freeway when it drones a bit especially on the uphill stretches.

 

From what I have been able to verify so far on the 2020 R is that with dynamic mode + active exhaust enabled the opening of the exhaust valves is tied to the aggressiveness of acceleration. The valves are either open or closed. Sitting at idle they will be fully open, light acceleration closes the valves. If you stomp it, the valves will remain open. If your cruising at say 30 they are closed until you stomp it and then they will open. With fuse 15 pulled, they are open all of the time. With dynamic mode off and Active Exhaust on I believe all of the same above applies just you are not getting the dynamic adjustment just exhaust noise.

 

JagBass, I believe you are precisely correct. The Dynamic Mode is not intended to vary the modulation of the exhaust valves, it’s an engine, transmission, etc., calibration modification that essentially makes the car more aggressive. Those aggressive reactions probably causes the exhaust valves to be open more often, but Dynamic will not lock the exhaust valves open at all times like pulling fuse 15 does. Pulling that fuse eliminates any electronic impulses getting to the valve and that valve is spring loaded to stay open when there’s no impulses to close it or modulate it’s position. Whether you’re cruising along at any speed, hitting the accelerator or applying the brakes, without that fuse, the valve is wide open all the time. Hearing and/or feeling those differences with or without fuse 15 is sensed by the operator and they either notice it or not their based on their sensitivity.

 

Ya but the main reason I wanted dynamic mode on all the time was to keep the valves open and get rid of the auto start/stop.
If I can pull a fuse and unplug the shut-off mechanism, I'm a happy camper!

 

OK... I didn't realize that dynamic mode didn't keep the valves open all the time like sport mode did in my Pcar. Appreciate the clarification.

 

The valves are actually vacuum actuated.

 

Neither did I and I'm still not convinced that's right in my MY18 - it certainly sounds like they're open all the time in dynamic.