I did a search, but only found information referring to the V8 cars. I never knew it was even there until I happen to look under the rear of the car and saw an "arm" that appears to be actuating some sort of flap or valve inside the muffler can. On this diagram, the arm doesn't have a # on it, but it the piece that comes off of #6. What is this and what does it do? I need to look closer when I get home, but thought I would ask...maybe I'm crazy.



No. Description Supplement Qty From Up To Part Number Price Notes
01 Rear muffler with exhaust flap 1 18307565687
02 CLAMPING BUSH D=85MM 1 18307560782
03 Bracket 1 18307521388 $16.96
04 Rubber Mounting 2 18207833206 $16.96
05 Collar nut M8-8-SC-ZNNIV 3 07119906089
06 Bracket 1 18307525633 $11.38
07 Exhaust pipe tip 2 18307536038 $42.97
08 Edge protection 1 51721866416 $7.25
09 ELECTR.VALVE 1 11741742712 $42.69
10 VACUUM HOSE BLACK 3,5X1,8 ? 11727545323
11 Cable grommet 1 61131361918 $0.99
12 Wire tape, outside serrations L=150MM/B=4,6MM 1 61136915978 $0.11

 

the valve opens up at higher speeds/rpm to increase the exhaust note. When the engine is revving at lower RPMs the valve closes, producing a quieter tone.

 

Don't laugh , German Noise Drive -by standards.....

Valve closed under set speed and RPM load ( in Vw and Porsches around 45mph) to keep the exhaust note under a set sound decibel level.

At speed and load it opens up, and then the car get loud and with Vw's and Porsches gains some noticeable HP and Lbs/ft #'s (R32's got in 3rd gear at 3200RPM an extra dyno proven 12-15 hp, H50 pack Porsche's have a button to defeat it and gain extra hp)

 

@bigbadbull is correct. I had a 2004 VW R32 and there was a trick where you could pull out the vacuum line and plug it with a screw, this would keep the valve open all the time and give you great sound at lower speeds.

Does anyone know if this is possible with our cars?

 

Yep. Google "golf Tee mod".

 

does anyone know a way to check this vavle to see if its working or what some symptoms of this valve no working would be?