Weird Noise From Bypass Valve after Turbo Inlet Install.

RichB

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2007 Cosmic Blue Mazdaspeed 3 GT
Compressor Stall after Turbo Inlet Install?

I recently installed my Turbo Inlet and am noticing a weird noise from the bypass valve when I am shifting gears. It was very apparent with my Forge and it occured right before the "Ping". When I put the stock valve back on it only happens sometimes under hard acceleration in 6th gear. Any thoughts to what this may be? I have already checked all of the fittings.
 
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Did some online research and it sounds like it could be compressor surge due to the bypass valve releasing too slowly. So for the stock BPV application this is just a high boost low RPM surge. With the Forge set-up (Blue Spring no Shims) the spring was just too stiff. If I still had the Forge I would try the yellow spring to see if the noise went away but it's gone so I can't.

Does this make sense to anyone?
 
I recently installed my Turbo Inlet and am noticing a weird noise from the bypass valve when I am shifting gears. It was very apparent with my Forge and it occured right before the "Ping". When I put the stock valve back on it only happens sometimes under hard acceleration in 6th gear. Any thoughts to what this may be? I have already checked all of the fittings.

Mine sounds like a groundhog bark. Others are having the same sound after installing the Cobb inlet. Different BPV are being used and still have the same sound. It's not surge but seems to be the released pressure hitting the silicone inlet. I'm not for sure what is happening but people running the metal inlets have not report this sound so I believe it has to do with the silicone inlets.
 
I wonder if Cobb or CP-E have anything to say about it.

I did read somewhere that someone with a metal inlet heard a similar sound.

I found a Youtube video of someones car that makes the same noise I am hearing

http://www.youtube.com/watch?v=OuNTnA5A2Fo

Note the title of the video.
 
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yea idk if maybe the springs are coming stiffer now or what, but when i bought my forge valve a few weeks ago from street unit the guy on the phone was like "dont listen to anyone on the forums about using the blue spring with or without shims and just run the yellow spring for now to break it in" and so i did for a day then i got curious and decided to put in the blue spring by itself to see what happens. well, it ran fine for like two minutes before it started sounding weird and i threw a CEL. so then i took the blue spring out. and i switched back to stock because i didnt like the sound of the forge valve. i dont know what im gonna get or just stay stock but i dont like the forge valve.
 
yea idk if maybe the springs are coming stiffer now or what, but when i bought my forge valve a few weeks ago from street unit the guy on the phone was like "dont listen to anyone on the forums about using the blue spring with or without shims and just run the yellow spring for now to break it in" and so i did for a day then i got curious and decided to put in the blue spring by itself to see what happens. well, it ran fine for like two minutes before it started sounding weird and i threw a CEL. so then i took the blue spring out. and i switched back to stock because i didnt like the sound of the forge valve. i dont know what im gonna get or just stay stock but i dont like the forge valve.

Wow really!

I think it would make more sense to run the yellow spring initially as well. I wonder what Forge has to say about this? Anyone wanna ask Patty AT Forge?
 
Posting this from Forge's website regarding Spring colors and application:

from Forge Motorsport's website
Now you can fine tune your Blow Off/Diverter Valve to the exact needs of your engine with this complete tuning kit.

Your valve tuning kit you will find four springs and three spacers.

The strongest spring is the red, followed by the blue, yellow and finally the green which is the weakest. The spacers enable you to fine tune the settings between two spring tensions if required.

We normally supply our valves, unless requested differently, with a spring that will match the tension of the manufacturer’s original fitment valve. However, as many owners undertake tuning modifications some may wish to re-tune the valve characteristics to suit a given application.

If you are finding that the valve is dumping more than required or you are loosing boost pressure it is normally an indication that a stronger spring is required. Conversely if the valve is failing to dump it may be necessary to install a weaker spring. If during this tuning of your valve you are faced for example with the red spring being to strong and the blue spring to weak, you can add the spacers to the blue spring to increase the tension by small increments, thus achieving a setting between the red and blue springs.
Valve Spring color coding
Green - 5-15 PSI
Yellow - 15-23 PSI
Blue - 23-30 PSI
Red - 30 + PSI
The above figures are estimates only and should only be considered as a guideline

Please note - fitting a stronger spring into a valve will not increase boost pressure unless existing pressure is being lost. Failure to allow the valve to operate by installing a spring which is to strong may cause damage to the turbocharger.

Please note - the red coded springs should not be installed in the DVR or DV007 diaphragm valves
 
Wow that thread is very informative!!!

I always thought the blue+2 was such a stiff setup, almost like we were forcing it to hold when it wanted to release.

Now the debate of yellow+1,2,0 begins. And I'm really intrigued if weather/seasons do have something to do with it.
 
Yea I thought Blue with 1 or 2 was a good set up as well. But when I put the Inlet on you could definitely hear something was off.

Weather does have an effect by the way which is why it is good to have an adjustable valve.
 
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I had the "bark" sound with blue an no shims and I get it with blue + 2 shims. I don't think it's compressor surge. I sure as hell hope it isn't anyway. I don't get it when really mashing the gas... only when building a decent load and quick shifting in traffic.
 
I had the "bark" sound with blue an no shims and I get it with blue + 2 shims. I don't think it's compressor surge. I sure as hell hope it isn't anyway. I don't get it when really mashing the gas... only when building a decent load and quick shifting in traffic.

try the yellow spring and see what happens.
 
At the request of Rich B:

I have modified my car since that thread, I now have Corksport Turbo Inlet and Intake (which I love...)

Driveability changes depending on the day though...it never likes to be spooled quickly then let off...its very much best to spool these cars slow or so it seems...

I am still running yellow with two springs and everything sounds like a normal turbo car...in fact the Corksport turbo inlet got rid of the ching sound of the Forge BPV. Of course depending on the boost pressure its releasing the Forge sounds different everytime...one of the girls I am dating thought it sounded COOL! like a video game! Yeah...not too bright...but thats the way I like em...

Back on topic I am thinking about going up to blue with no shims. I do feel as though the yellow now is not stiff enough. The car spools much quicker now especially with the test pipe. I still am getting the turbo whine up top even when warm and filled with fresh oil. I think this turbo is going to have to be replaced or rebuilt before 30,000 miles. Its fine by me I know how these turbo cars act...very finicky....I dont even drive it hard I am usually very nice to my car...I just go around corners fast, as evidenced by my ability to wear out the front tires in 6000 miles without EVER launching the car.

As for the bark noises you guys are talking about, that to me sounds like a very fast open and close of the BPV which is what happens when you shift gears fast and get back on it again...then the BPV basically "coughs" and slams shut again...it could be metal on metal in which case the valve needs to be cleaned and lubricated which it needs anyway every 6-8 months...

I will try the blue with no shims setup and see what I find...
 
I still am getting the turbo whine up top even when warm and filled with fresh oil.

Turbo whine? Replace in 30,000 miles? Can you elaborate? Thanks.

Edit: About the "bark" sound: I am convinced it's happening in the inlet. It just sounds like the inlet. I can't explain why, it's just a feeling I have. It sounds like what would happen if you coughed through the inlet as hard as you can one quick time.
 

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