[lilmanvc15]

So I did the secondary cat and 1st resonator delete last night, I thought it would be much louder then it was not as crazy as I anticipated. When I was parking my car I can here the popping from the exhaust in m2 mode at idle, at this point I knew the valves was being restricted down by the ecu. I am looking to do this mod today and hopefully have a wonderful sounding exhaust setup. Cost to do the secondary cat and primary first resonator was 300 dollars at a muffler shop for context.

[lilmanvc15]

Originally Posted by Reprosal

I am not comfortable doing the manual zip tie process. This is a forever car for me until it ‘dies’. I may just do the primary resonator and secondary cats delete.

sounds so amazing when you do but this mod for the exhaust will take it to a whole other level. when you do the exhaust mod for the cat and resonator the car will pull more than you expect

[Speedyf16]

I went the route of removing the theta plate and spring and bolting the still plugged-in controller back on. It works, but as others say, there's some embarrassingly loud rattling whenever the exhaust gas velocity is low at lower rpm. Didn't have small hose clamps at home so will grab a pair today or tomorrow to secure the valve in the open position tightly.

Also, like one poster said I think, the valve keeps sucking back to the fully closed position after shutting off the engine. It seems there must be an instantaneous moment of negative pressure when the ignition is killed that sucks the valve closed. Just have to go under the car again and finger the butterfly valve to re-open it...and soon enough secure it with a hose clamp.

[Berzerker]

Originally Posted by Speedyf16

I went the route of removing the theta plate and spring and bolting the still plugged-in controller back on. It works, but as others say, there's some embarrassingly loud rattling whenever the exhaust gas velocity is low at lower rpm. Didn't have small hose clamps at home so will grab a pair today or tomorrow to secure the valve in the open position tightly.

Also, like one poster said I think, the valve keeps sucking back to the fully closed position after shutting off the engine. It seems there must be an instantaneous moment of negative pressure when the ignition is killed that sucks the valve closed. Just have to go under the car again and finger the butterfly valve to re-open it...and soon enough secure it with a hose clamp.

Why not get a valve controller?

[Vic55]

Originally on my 21 and 22 G80s; I just made sure the valves were open and detached the sensors locking them open. But with my 24 CS when we went to do this, the left valve was wide open but the right was not fully open even after multiple revs and the car in Sport Plus.

1. did something change with the 23 or 24 models?
2. will a valve controller make both sides fully open

[Speedyf16]

Originally Posted by Berzerker

Why not get a valve controller?

Because even with both flaps open permanently now, it's still not really "loud" haha and there's zero drone at any speed.

Got the hose clamps on today (passenger side was...fun...) and now there's zero rattle. Very content with the setup!

As a reference point, I forced the valves permanently open on both my previous V8 F-Pace SVRs and I never had the desire to be able to close them over 4.5 years...enjoyed the raucous cold starts and allllll the pops n' bangs on the overrun.

[Speedyf16]

Originally Posted by Vic55

Originally on my 21 and 22 G80s; I just made sure the valves were open and detached the sensors locking them open. But with my 24 CS when we went to do this, the left valve was wide open but the right was not fully open even after multiple revs and the car in Sport Plus.

1. did something change with the 23 or 24 models?
2. will a valve controller make both sides fully open

Yea, your only real hope to do it that way would be to disconnect the sensors while somebody is wide open throttle on a dyno ...disconnecting while just revving it in place is unlikely to catch them at exactly the 100% open position...could keep trying though.