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View Full Version : Forge valve and Mazda CAI


pmarcian
12-28-2008, 10:52 PM
Just started modding the car with a Forge recirculation valve (installed a few weeks ago). Seemed to work fine. Yesterday I had the car up changing the oil and trans fluid (MT90) and installed the Mazdaspeed CAI. Car drives great but the Forge valve makes an awful noise. I read on the forum they tend to do that but it didn't make any noise before installing the CAI. Took the Forge off this morning and put the stock valve back and no more noise. Is there any cure for this? The noise was scary - thought I forgot to tighten a hose and had a major boost leak.
DaleNixon
12-28-2008, 10:54 PM
Hehehe. Does it sound like two swords clanging together in the engine bay?

http://www.youtube.com/watch?v=xW3E0DGxFjo

(headbang)
pmarcian
12-28-2008, 11:09 PM
That's it! Scared the hell out of me. How come it didn't do it with the stock airbox?

I have a forge DV in my Audi TT and it doesn't make any noise - at least none that scare me.
DaleNixon
12-28-2008, 11:26 PM
From what I understand, the stock airbox mutes a lot of noises. I had a PSHT sound with my HKS SRI even without the Forge BPV. When I installed the Forge, it blew me away. But I was expecting the sound as I had read about it beforehand.

Hopefully you like it or can live with it. If not, you might want to consider selling the Forge BPV.
mr_mazda329
12-29-2008, 12:27 AM
I love the sound of the Forge. It's a very unique sound.
Silver Ecstasy
12-29-2008, 01:12 AM
What did it sound like with the stock airbox? I've read that changing the bpv to an aftermarket can even improve the car's boost characteristics, even stock. But i've been persuaded against getting it as my first mod and instead letting the intake be the first mod.
Speed3Rookie
12-29-2008, 01:17 AM
What did it sound like with the stock airbox? I've read that changing the bpv to an aftermarket can even improve the car's boost characteristics, even stock. But i've been persuaded against getting it as my first mod and instead letting the intake be the first mod.

lol...screw that. Better get engine and a tranny mount.
Silver Ecstasy
12-29-2008, 01:28 AM
Actually, I mis-spoke. I have TWM SS and CS Inserts. But no thread-jacking, so I'll keep that out of this thread.

Would the Forge be pretty silent or hardly noticable with stock airbox?
mr_mazda329
12-29-2008, 01:42 AM
Actually, I mis-spoke. I have TWM SS and CS Inserts. But no thread-jacking, so I'll keep that out of this thread.

Would the Forge be pretty silent or hardly noticable with stock airbox?


Yes, very silent. But you can slightly hear it while getting on it hard, but still quiet. You have to actually consentrate on trying to hear it. You can't hear it at all with the windows up.
DaleNixon
12-29-2008, 10:08 AM
Yes I have my factory air box + Forge BPV currently (Cobb intake should arrive today ). With the factory box, you sometimes hear the metal ping if you really push it. Otherwise, no difference from stock.
Silver Ecstasy
12-29-2008, 12:58 PM
Okay, thanks for the inputs!
ZyrehT
12-31-2008, 01:19 PM
Hehehe. Does it sound like two swords clanging together in the engine bay?

http://www.youtube.com/watch?v=xW3E0DGxFjo

(headbang)

I still don't understand how a pressurized air sound is like swords clanging. I know it's been said before but it has to be the dumbest sound comparison I've heard.
pmarcian
12-31-2008, 01:45 PM
It's the sound of a metal piston hitting the metal body attached to a hollow pipe. I have a Forge DV in my Audi but it's attached to silicone hoses and doesn't make a racket. It really is scary if you aren't expecting it.
tru-boost
12-31-2008, 11:51 PM
That sound has been there all along you just couldnt hear it through that restrictive stock airbox. Dont be shy with the spings and shims. Stiffen that bad boy up ! If you can work up to the red spring that high pitched sound goes away. Just make sure you dont get compressor surge from runnimg it too stiff for your set up.
ZyrehT
12-31-2008, 11:53 PM
It's the sound of a metal piston hitting the metal body attached to a hollow pipe. I have a Forge DV in my Audi but it's attached to silicone hoses and doesn't make a racket. It really is scary if you aren't expecting it.

No it isn't, it's just the whistle of compressed air. There was something posted by somebody from forge over a year ago on another site about it.