I had my secondary cats removed by Evosport a couple weeks ago and really like the results. There is better throttle response now especially off the line. I remember when I first drove the M6 I thought I left the parking brake on or left it in nuetral since it was so sluggishly delayed starting out. Now it is more instant. I do not know how much hp or torque gain if any, but the car feels quicker. Sorry for the seat of pants only measurment.
Secondly I loved the sound of the Eisenmann race exhaust, but would have liked more low end growl and there was some serious bass resonance around 3400 rpms in the cabin that was a little too loud for most passengers. Of course it only happened at or around that rpm. Now with the 2ndary cats out I have the low end bassey growl and the resonance is gone!
This is a video of the exhaust sound after 2ndary cats out.
http://www.youtube.com/watch?v=Qlrjox2am9I
This is a video comparing the before and after taking cats out.
http://www.youtube.com/watch?v=Zv3L5qR0NoI
Enjoy I hope this is helpful.:M5thumbs:
Secondly I loved the sound of the Eisenmann race exhaust, but would have liked more low end growl and there was some serious bass resonance around 3400 rpms in the cabin that was a little too loud for most passengers. Of course it only happened at or around that rpm. Now with the 2ndary cats out I have the low end bassey growl and the resonance is gone!
This is a video of the exhaust sound after 2ndary cats out.
http://www.youtube.com/watch?v=Qlrjox2am9I
This is a video comparing the before and after taking cats out.
http://www.youtube.com/watch?v=Zv3L5qR0NoI
Enjoy I hope this is helpful.:M5thumbs: