High Boost Atmospheric BOV Turbo Dump Valve

[Olivier]

Hello all,

Is that any good as a MOD, or not really? When I left the throttle I do hear a loud woosshhh sound, would that be the air coming back to the turbo? Will this prevent it and stop a bit the turbo lag?
THis is for a E300 Turbo diesel.
Cheers.

http://cgi.ebay.co.uk/High-Boost-Atmospheric-BOV-Turbo-Dump-Valve-30mm-Inlet-/380314811655?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item588c877d07

wiki:
http://en.wikipedia.org/wiki/Blowoff_valve
Blowoff valves are used to prevent compressor surge, a phenomenon that readily occurs when lifting off the throttle of an unvented, turbocharged engine. When the throttle plate on a turbocharged engine closes, the high pressure air in the intake system is trapped by the throttle and a pressure wave is forced back into the compressor. The compressor wheel slows rapidly and may even stall, and the driver will notice a fluttering air sound. The rapid slowing or stalling stresses the turbo and imparts severe turbo lag if the driver accelerates immediately after the surge event.

[aaa]

Woosh doesn't sound like the sound this is supposed to solve. Plus these are designed for gassers, you don't even have a throttle plate for one.

[Olivier]

Aaa, not for diesel then? Why not? I know the throttle is always open but if the valves are close the pressurised air as to go somewhere?
The sound is a funny one one, hard to tell, wwoooshh, a bit like something sucking in too, when the waste gate open I guess. I thought it might be the turbo lowering its speed with the air going backward like explained on wiki...
Cheers.

[babymog]

The pedal doesn't close the valves. Airflow through the engine will decrease with RPMs, and the turbo will decelerate with it.

As said, blowoff valves are for throttled engines (gasoline).

[Olivier]

OK, thank you.

[Marvelicious]

I sense something… a presence I've not felt since…

[josha37]

its wierd i was thinking the same thing...

[ForcedInduction]

Originally Posted by Olivier

When I left the throttle I do hear a loud woosshhh sound, would that be the air coming back to the turbo?

Like this? http://www.youtube.com/watch?v=6y_tbIStALM
The solution is to stop lifting the accelerator suddenly.

That said, there IS a use for an air recirculation valve to prevent surge. I have one on my engine because the turbo spools up too fast and surges when the engine is below 2000rpm. I had Bob (techguy512) modify one of his tach amps to control a solenoid that activates the ARV based only on engine RPM.
http://mercedesforum.com/forum/diesel-performance-49/forcedinductions-gt2356v-hybrid-vnt-turbo-48247/#post150502


The black can is a muffler. No ricer BOV farts allowed here.