BMW vacuum exhaust baffle.

[oldcarman]

Those are two completely different animals and becomes a matter of preference in the end and usually comes down to packaging the unit within the confines of the engine compartment. Having looked in my engine compartment I think a turbo or two are more viable than a supercharger and having a boost controller in the cab is a bonus! JMO JIM

 

[Dickymint]

where is this vacuum operated flap? today I had a look under the car and cant feel/find anything to operate a flap though there is something that feels rubbery sticking out the back of the back box about 3inches but no vacuum on it or does mine just not have one? the back box is genuine BMW

p.s its the one with twin pipe inputs and I intend getting a stainless steal exhaust fitted soon if my other problem is easy sorted that's the reason for asking

 

[t-tony]

If it's like mine @Dickymint, when you look from the rear it's in the right hand tailpipe and if you look under the rear silencer there is a vac capsule with a thin rubber pipe attached.HTH.

Tony.