Forge BPV install and impressions.

I would say those are both Surge. What I call flutter is the BPV trying to decide to release or not. It will sometimes open and shut rapidly causing a fluttering sound.
 
No. I here a loud compressor surge in the videos. If my car was doing that I would pull over and tow it home. Flutter is mearly air being release by the BPV but in a way that is on and off rapidly. Everytime you let up while in throttle the BPV releases. At partial throttle and release the BPV is right at the release don't release point and it will flutter. Surge is a large volume of air being released that stops the turbo. I'm not an expert by any means but I have flutter sometimes but never surge. I run blue with two shims on my Forge.
 
Last edited:
08cosmic3 said:
No. I here a loud compressor surge in the videos. If my car was doing that I would pull over and tow it home. Flutter is mearly air being release by the BPV but in a way that is on and off rapidly. Everytime you let up while in throttle the BPV releases. At partial throttle and release the BPV is right at the release don't release point and it will flutter. Surge is a large volume of air being released that stops the turbo. I'm not an expert by any means but I have flutter sometimes but never surge. I run blue with two shims on my Forge.
Click to expand...

Scratch this post. I believe I have the surge part wrong and will stop here and let someone with more knowledge explain.
 
My car doesn't really flutter unless im on and off the throttle gently. A "little" flutter means your bpv is working properly. You dont want one that blows off too easily like the yellow spring on my car. But you dont want one too hard either.
 
08cosmic3 said:
Not the Cobb Turbo inlet I have.
Click to expand...

I've been told the turbo inlets that are made of an actual hard pipe are ALOT louder than the silicone hose used like with cobb's. I heard the RPMC and forge in person and did not hear a ping when he let off the gas...i was like wtf are you sure that is a forge? Sure it enough it was. it was loud and sounded GREAT. I am sure there may still be somewhat of a ping, but its not near as pronounced.
 
I have the Forge and i did not like the sound at first. That changed over time, but Patty says flutter is fine and when i gently decelerate coming out of marginal boost i get flutter and it cracks me up. I have played with springs and shims and found that for my car blue with one or two shims works best for my boost levels. Flutter sounds nothing like the Sr20 clip on my car. That clip does not sound healthy. I am sure i am not stalling my turbo. Mistersix i believe is correct, some units are designed for sound. I have a fellow Speedster out my way who runs a turbosmart and it is much more extreme than my Black Forge. And pretty cool sounding too. His is more in your face. I have found with mine I can drive stealthy and keep it quiet or you can let someone know if you want to that " thats right, I have a turbo!" nice.
 
I got a chance to ride around in a Forge-equipped MS3 today and I must say, that sound definitely grows on you! I asked about the flutter it basically does it when you're just casually driving through traffic and start to ease off boost. The BPV just tries to calmly let the boost out. Our stock BPV's do that too only they're a lot sloppier of a flutter, almost to a weak psssh.

That, and the car runs incredibly well and maintains zero inappropriate LTFT's and KR.
 
someone suggested underneath the spring. i tried it today and it makes sense, since its to hard to get the shim centered on top the spring.
 
I just put mine in today. What exactly do the shims do? I have a COBB SRI and I'm running the blue spring like most people seem to have. I'm not sure if I'm really feeling the difference with the shims in or out though.
 
Boostin McFly said:
I just put mine in today. What exactly do the shims do? I have a COBB SRI and I'm running the blue spring like most people seem to have. I'm not sure if I'm really feeling the difference with the shims in or out though.
Click to expand...

It puts a slight precompression on the spring, in effect making it marginally stiffer.
 
Maybe if you start with the softest back pressure setting {yellow with no shim{ am i correct on this patty at forge] all the way up to the blue with two. No need to use red probably( the stiffest resistance for higher boost). And then, BoostMcFly, drive with each setup on for a week or two straight driving easy and a little hard too, and report back to us. I think you might have some opinions and have some fun doing it. I hope your question will be answered also. the shim adds stiffness to the particular spring you are using. Give it a try. And mid life is right again on this
 
ericrapp said:
Maybe if you start with the softest back pressure setting {yellow with no shim{ am i correct on this patty at forge] all the way up to the blue with two. No need to use red probably( the stiffest resistance for higher boost). And then, BoostMcFly, drive with each setup on for a week or two straight driving easy and a little hard too, and report back to us. I think you might have some opinions and have some fun doing it. I hope your question will be answered also. the shim adds stiffness to the particular spring you are using. Give it a try. And mid life is right again on this
Click to expand...

Ok I'll try this. I thought just doing it might yield some instant results but I'll try the 6 setups for a couple of days each and check back in. Thanks
 
Yellow with no spring is the softest that we send with the MAZ3 valves, although there are softer setups but they wouldn't work so hot for you guys.
 
SubieKiller3 said:
did any of you guys have a problem with the stock clamps being loose? i heard that most people have had to get tighter clamps to hold down better. or maybe forge has fixed this problem yet?
Click to expand...
Don't see this as a Forge problem... the stock clamps suck anyway, .99c at the auto parts store gets you a new adjustable clamp. ;)
 
Please log in or register to reply here.

New Posts and Comments

ruthrj
    • Thanks!
    • Like
Mazda Infotainment Settlement
2 3
Replies
48
Views
6K
jim2016cx5
J
S
  • Question Question
Camping with CX-5 Powerlift Gate
Replies
8
Views
312
N7turbo
N7turbo
C
Radiator / Condenser fans not kicking on
Replies
2
Views
101
Cuttness
C
Z
Better to get new off the shelf exhaust system or custom?
Replies
3
Views
148
N7turbo
N7turbo
Y
2013~2016 Front Driver Side Clunk on Mazda CX-5 2014 – Need Help
Replies
0
Views
28
youcefphily
Y
R
    • Wow
2017 CX-5 2.5L Crank No Start issue
2
Replies
39
Views
1K
Mazdiod2
Mazdiod2
View more…

New Threads and Articles

Back