When i press the sport button in my 997 tt the tune of the exhust sound changed and become loud , this is normal for all 997 tt or not ?!

Thank you

 

If you want to know if there's an aftermarket exhaust on the car, just peek under the rear bumper. You'll be able to tell right away.

 

+1. If you're still not sure, take a pic
It is normal for the exhaust note to become louder and more aggressive when I'm Sport mode though

 

I'd be interested in knowing as well.

 

There has been much debate on this but the general consensus, if i remember correctly, is yes it does change. But it is not from anything in the exhaust (nothing changes im the actual exhaust) per-say but instead from the angle change of vanes in the variable turbos at idle and the quicker spool up under throttle and increased boost at wot. Im sure others will say more.

 

seems normal to me. just bought a 2011 turbo s and the same thing happens...I love it! I'm beginning to drive around in sport mode more often...

 

first thing i do whenever i get in the car after buckling my seatbelt.

OP yes this is normal - i agree with ecp's comment above, take a picture from underneath the car and we can tell you very quickly if you still aren't sure.

 

From the tuning point of view yes the sound 'can' change when you switch from normal to sport. There are two reasons for the change in sound. One is the cam timing is different in the low RPM low load area between normal and sport. Also base VTG duty cycle differs between the two where one mode can have the exhaust side freer flowing than the other at the low rpm/low load area.

Dzenno@PTF

 

Mine still makes the same sound change with non vtg's

 

Right. Without VTGs in place the only other thing you have is cam timing as mentioned above.

Dzenno@PTF