Supra Forums banner
1 - 20 of 23 Posts

·
71 Millimeters
Joined
·
458 Posts
that is defintely Greddy Types RS
 

·
The Sethster
Joined
·
971 Posts
most of that sound is turbo cliping
 

·
Registered
Joined
·
38 Posts
Turbo clipping?? You mean compressor stall?
 

·
Ticketing Ricers Evrywhre
Joined
·
1,485 Posts
Discussion Starter · #6 ·
I saw a GTi that had that same BOV at the gas station today. Is it just an Audi/VW thing? Because the one in the vid is a TT...
 

·
Registered
Joined
·
38 Posts
Thats a characteristic of the BOV but its not how its designed. It would still be partial compressor stall making the chipmunk noise;)
 

·
ƒ=1/2π(√k/m)
Joined
·
10,143 Posts
No BOV should ever "be designed" to make that sound... it's impossible.

It's just a valve and spring design that's opened with vacuum.

If you ever hear that sound, it's compressor surge.
 

·
Registered
Joined
·
38 Posts
Compressor surge is surging while under boost... Compressor stall is when the excess pressure on the compressor side of the turbo overcomes the press on the exhaust side of the turbo causing compressor stall. Its not compressor surge.


<Edit> Err well some people call it compressor surge but its actually the compressor stalling, or stopping. So, I guess you could call it what you wish but the correct term for what is causing the sound is compressor stall. Compressor surge happens when the compressor section of the turbo has produced more pressure in front of it than the exhaust section can support, therefore the boost pressures will surge because the pressure ratio is not sufficient to keep the turbo at effecient flow and it will slow back down... then speed back up when the pressure ratio returns to a higher level and the cycle will continue... etc etc etc. This is the reason for the "anti-surge" housings on most of the larger turbos from HKS, SP etc etc.
 

·
Registered
Joined
·
38 Posts
Thank you for being to receptive to my explanation of what STALLING means..... However... turbos don't spin in excess of 150k rpms in automotive applications. You can try to find something wrong in what I have said because I am I "newbie" by post count if you wish. However if you would do some research on turbochargers and their related technologies you will see that I am correct.

IN FACT... if the compressor stall is bad enough the turbo will begin to spin backwards. Call Garrett and ask them about it, read a book about turbos, you will find it to be true.
 

·
Beats and Rhythm
Joined
·
2,732 Posts
MaliCali said:
:lol: the fuck is compressor stall

you talking about compressor SURGE..

:1poke:

Haha Yeah, my exact thoughts scrolling the thread. :sadance:
 

·
Beats and Rhythm
Joined
·
2,732 Posts
Compressor surge: You can think or surge as the point at which the compressor blades begin to “slip” in the air, losing their pumping ability, much like an aircraft wing loses its lift when it stalls. In a turbo, this happens in a series of bursts, as the blades slip, then bite, slip then bite. This sets up a pulsing wave in the turbo piping and explains why the sound has that characteristic “flutter”.
The turbine will never stop and start again, rather compressor surge is simply the air bouncing back and fourth through the intake piping and hitting the closed throttle body while more air is actually being pumped.

There is zero way a turbocharger can simply stall or "stop" in motion while the engine is still compressing air ( the air trapped in the intake chamber/piping). This being said there will always be exhaust as long there is a spark and the turbine will inevitably be in motion (perpetually as long as the pistons are compressing ). And as long as there is exhaust flowing the turbine will be spinning.
 
G

·
Xracer2JZ said:
There are some BOV that actaulyl flutter and its not jsut comrpessor surge. i know one of the blitz BOV's flutters.
also ture, the blitz does also what you called "flutter"... its nto always compressor surge... Comp surge actually sounds a little "faster"...But yeah, the older blitz deff. sounds "fluttered"

more BOV's that soudn like this are

TIAL
Turbosmart
GoFASTbits
ARC
 

·
Beats and Rhythm
Joined
·
2,732 Posts
There is not one blow off valve that sounds futtered when operating CORRECTLY.

All must discharge the air in one burst without any interuptions. The sheer mechanics of a blow off valve will never create a flutter sound. Of course like HKS has on the SSQV you can put in adapters to change the tone/pitch of the air being expelled from a deep "woosh" to a bird like "chirp".
 

·
Andy Warren
Joined
·
23 Posts
BOV Flutter. Sounds similar to a TiaL but it's too hard to tell. Sounds like he may need a lighter spring in it to get it to open easier. Either way, it's definitely a plunger-type BOV like a Greddy, TiaL, Blitz, etc.
 
1 - 20 of 23 Posts
Top