exhaust noise diverter

[V6quattro]

Here are some photo's from my set up. I really wanted the OE look rear muffler. I also wanted it to react immediately so the slow electric ones ware no good to my. And of-course it should absolutely not effect the performance. O and i also did want to keep my 3.5'' middle box.

So i modified the rear muffler a lot to get it all to fit. Its all controlled by vems. When i shift back and go past 3750rpm the valve opens immediately. I could not find a 3.5'' vacuum cut out so i used a 4'' china throttlebody.

After doing all this will i do it different the next time? Yes of course I think i will use OE rear and middle muffler to get the noise down moor and place the 110mm cut-out where i have my 3.5'' muffler now.

[A1quattro]

great response ,thanks all. I was only going to fit the device in line just before the rear box [single box system] so that it simply closes or part closes the flow , with no other out lets or side pipe fitted . the reason for this is I have to pass noise test at every rally, so I can simply close flap for that then re-open welst rallying . For 10 years rallying the Quattro with a stainless 6.5kg 14" silencer we go threw noise test around 95db with no problems , limit at most places is 100db , over the years many people have said the car looks quick [which we are ] but its to quite ,, so now ive decided to do something about it , going to fit a 10" alloy silencer only 1kg the new exhaust flap device weighs 1.5 kg but even with that fitted weve still saved 4kg [ which helps me sleep at night ,with my weight loosing obsession ] plus the car should at last sound more like a rally Quattro

[Rusty]

Just have a centre silencer in a big U shape and bridge the gap. Means you have the rear free for a big diffuser