Best options for 812 exhaust (rear boxes)?

thoughts on 400cell?

 

I didnt know they made them. I dont think any number of cells can really go around GPF. I was under the impression GPF has additional pressure monitoring tubes that are connected to the computer. I dont think a regular catalytic converter works.

 

Anyone else with some feedback on 200 cell cats and superfast pre GPF?

 

I fitted BRE sports cats and X pipe plus valve controller from ASR. Sound is perfect for me, louder and F1 scream up the rev range. No CEL either. I didnt replace the back box simply because with the valves open I didnt think there would be much benefit changing but others may have a different opinion.

 

You should be fine. I have Capristo 250 cell and IMO it's perfect. Really brings out the loudness and the shriek of the V12 without any drone or overbearing. I have stock muffler with valve control. BTW valve controller is a waste of money if you have sport cats, first thing I do is to open valves every time I start the car. If you are straight piped then that's different story.

 

no codes? Did you have a GPF car?

 

no codes. pre gpf.

 

Hi all
Last year i went with 200 cell sports cats and x pipe with valve controller but avoided getting aftermarket rear mufflers because i always have the valves open and i understood that the rear box is essentially like straight pipes when the valves are open. However, I have since been told that the factory mufflers, when the valve is open, it is only straight through circa 60%. Is that correct? Does any have only aftermarket mufflers fitted and can share their experience compared to factory?