Standard FD dump valves

[WeasleRx7]

I was hoping someone could just clarify something for me.

The FD has 2 standard dump valves, one for each turbo.  These are the denso units that recirculate the air back to the standard air box, through the 2 pipes on the back left of the air box.  Top pipe appears to be 2nd turbo, and bottom the 1st.

So to achieve the desired whooooosh sounds I just remove the 2 pipes from the back of the air box, and plug up the holes they\'ve left.

I\'ve done this so far, and all seems ok.

If I want a louder whoosh sound later on, I would just replace the denso valve with aftermarket jobbies?

Sound about right??

[rmagictastic]

i am confused, my pipes go to my filter, i have standerd denso valves, but my car is very wooooshy, is this not ussually the case?
and i thought i only had one BOV??

Nick

[WeasleRx7]

If you have some sort of performance filter that does away with the standard air box, then you will hear the standard dump valves through the filter itself.  The standard air box is fully enclosed so it mutes the whoosh noise.  I\'m not entirely sure that its a dump valve for each turbo, hence why I posted to get some clarification.

[fro]

There\'s one dump valve and a charge relief valve which does an entirely different job (although the look the same). You\'ll just need to unplug the DV from the air box (although I\'d imagine it\'ll sound pants)

[fro]

forgot to mention - won\'t the DV be open at idle so It\'d have to be plugged into the filter to stop you from sucking unfiltered air straight into the intake?

[WeasleRx7]

I\'ll check that out this morning, and if it is open at idle I\'ll stick one of those mini cone filters on the pipe.

As for the sound, it\'s quite soft, and fairly quiet.  I quite like it.

So what does the charge relief valve do? and when does it operate?  It obviously \'relieves charge\' as it\'s name suggests, but from where and at which point??

[MillSpeed]

When the turbo control system starts to pre-spool the secondary turbo (think this starts around 4000rpm), the charge control vavle is still closed. If the pressurised air the second turbo is generating is not vented it\'ll quickly stall the turbo. The charge relief valve simply vents this air back to the air box and allows the secondary turbo to spool and go into surge. As soon as you reach 4500rpm, the exhaust gasses are directed only through the secondary turbo, the charge relief valve closes and the charge control valve opens allowing the boost from the secondary turbo (which is now spinning like f*ck!!) into the engine.