[Danxr46]

Hi, how is everyone and their 'R's? Just a quick question to say what position their flapper valve plate is in when car is not running.

Does the flapper close when a billed air is ran to it upon idle and then gradually opens when pressure at 3500rpm is sufficient to open it?

If anyone knows the exact way it works to let let me know then that would be great.

I had a look at mine to see if the 'Flapper mod' was worth doing but I can't seem to get the pipe off.

Many thanks

DR B

 

[cuprabob]

The valve is closed at idle and opens at around 2,800rpm.

 

[Danxr46]

Hi, I did know that but is it open until car starts up and then closed until its sufficient pressure at 3000rpm to open? Mine is open looking at it when car is not running n

 

[cuprabob]

The default position is open when there is no vacuum hence why it's open when the pipe is removed.

 

[CorradoR32]

Cool. I was wondering what conditions opened the flap too. Is it literally just a fixed rpm? No load involvement?

Is the flap purely for noise or does it make more power? If the former, I'll be deleting it.

 

[cuprabob]

The flap is just for noise and has no real impact on performance.

I'm pretty sure it's operation is purely rpm based, but have never confirmed.

 

[Danxr46]

Worked it out from my knowledge. If you think of it like a waste gate, when engine is ticking over the flap is closed. When sufficient build up is there and activated with an electric cut off it moves a small control wire which operates the disc like a butterfly valve. No reason for having it other than purely for noise deadening at low rpm's. it will keep it quiet while strolling along but will be activated when the foot is being planted and more. If taken out or made redundant then it purely allows your car to have that raspy noise of the higher end, at the lower end.