Thanks for the input F430TECH. I agree with Dalenixon though that it is definitely not coming from the valve. I even greased mine and went out on another run but the noise was still very aparent. I even found a way to make that noise with my stock valve on, though it is in a very un realistic condition (Hard acceleration in a high gear).
Weird Noise From Bypass Valve after Turbo Inlet Install.
- Thread starter RichB
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Silver Ecstasy
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- 11 MS3 Sport
Search is proving fruitful.
Surprisingly, some people said Yellow was weaker than stock, held less boost.
Surprisingly, some people said Yellow was weaker than stock, held less boost.
To reiterate what I said in the other thread, there are two important parameters to this, spring rate (the rate at which the spring compresses for a given force - lbs/inch) and the spring preload (the force required to begin to lift the valve off the seat - lbs).
In my opinion, for a basically stock motor, you want the valve to begin to open at a similar vacuum to the stock valve, and open as quickly as possible when you reach that point. To achieve this, I use the yellow spring and one shim, as measured with a vacuum pump and a vacuum gauge, and it starts opening at slightly more vacuum than my stock valve. The opening vacuum is only controlled by the preload. The preload is quite sensitive to manufacturing variability in the spring as it depends on the free length, so the only way to determine if you need shims of not is to measure it. The spring rate should be quite consistent across manufacturing tolerences as it only depends on the wire diameter and the length of the wire used to make up the spring.
In my opinion, for a basically stock motor, you want the valve to begin to open at a similar vacuum to the stock valve, and open as quickly as possible when you reach that point. To achieve this, I use the yellow spring and one shim, as measured with a vacuum pump and a vacuum gauge, and it starts opening at slightly more vacuum than my stock valve. The opening vacuum is only controlled by the preload. The preload is quite sensitive to manufacturing variability in the spring as it depends on the free length, so the only way to determine if you need shims of not is to measure it. The spring rate should be quite consistent across manufacturing tolerences as it only depends on the wire diameter and the length of the wire used to make up the spring.
astraelraen
Member
I'll have to check my garage when I get home to see which springs aren't installed, but I'm pretty sure on my CX7 the yellow spring will only hold ~10lbs of boost. I've tested it with dashhawk logs.
Ever since installing my turbo inlet i get different bov sounds, I get baby hiccups from mine, also i get backfiring all the time when recirculating the valve. I actually get less backfiring when running it VTA.
Not sure what's up with the inlet and how to adjust the valve properly with the inlet pipe. Maybe it needs to be looser since the inlet allows for more airflow? Im completely lost!
Not sure what's up with the inlet and how to adjust the valve properly with the inlet pipe. Maybe it needs to be looser since the inlet allows for more airflow? Im completely lost!
Do you have a silicone or metal inlet?
I don't think the inlet is the problem. I think things just need to be tuned different. I am wondering if people who have other inlets (silicon or metal) are hearing the bark too.
I just conducted an experiment which had the results I expected as I've done it before with the same results. I've had the forge for almost a year and have been running Blue with two shims all that time.
I removed the two shims and went for a drive and noticed right away that the car was smoother and the Forge sound was quieter, I assume it's holding less boost so it makes less sound when released. I made several WOT runs through the gears and the car did not seem to have the EDGE it had before and the bark was still present.
I put the two shims back in with the blue spring and went back out. I noticed right away that the Forge was louder and the lower RPM shifts were not as smooth, however when I had the chance to go WOT through the gears it was very obvious that the car pulled stronger and the Forge held boost between shifts better. The car has no hesitation between shifts at WOT and seems eager to get to the next gear with boost pent up and waiting.
In other past threads Patty at Forge has said that for a stock car use the blue spring and with bolt ons use the blue with one or two shims.
Search "Patty".
I'm staying Blue W/2
I removed the two shims and went for a drive and noticed right away that the car was smoother and the Forge sound was quieter, I assume it's holding less boost so it makes less sound when released. I made several WOT runs through the gears and the car did not seem to have the EDGE it had before and the bark was still present.
I put the two shims back in with the blue spring and went back out. I noticed right away that the Forge was louder and the lower RPM shifts were not as smooth, however when I had the chance to go WOT through the gears it was very obvious that the car pulled stronger and the Forge held boost between shifts better. The car has no hesitation between shifts at WOT and seems eager to get to the next gear with boost pent up and waiting.
In other past threads Patty at Forge has said that for a stock car use the blue spring and with bolt ons use the blue with one or two shims.
Search "Patty".
I'm staying Blue W/2
That is good info 08cosmic3. Thanks for the experiment. I agree that your set up is edgier but the part that worries me is the pressure spike between the throttle body and the turbo (which I think is the cause of the bark). Looking at my boost gauge (which measures intake manifold pressure) both set ups held about 18 PSI with no creep, so I don't think loosing boost is the issue. It has to be the pre load in the springs.
The yellow spring has crappy pre load but it opens the valve at the right time(hence the smoothness). The blue spring has the perfect pre load but it doesn't open fast enough (delayed valve opening causing the bark).
Does this make sense to anyone or am I rambling here.
The yellow spring has crappy pre load but it opens the valve at the right time(hence the smoothness). The blue spring has the perfect pre load but it doesn't open fast enough (delayed valve opening causing the bark).
Does this make sense to anyone or am I rambling here.
Hmm maybe you are right. Rotus8 and F430Tech were doing some nice experiments with the different spring configurations. As noted earlier in this thread, that kind of stopped. I believe it was Rotus8 who was very happy with the Yellow + shims. Personally, I feel the car runs fantastic with my mods and the Forge blue + 2 shims, but I don't want compressor surge if that's what it is.
I'll probably just stick with the blue + 2 until further research is conducted. Too bad Patty isn't around too often. I bet she's hot!
Springs in the attic? Wow! Mine are in the hatch with my tire iron and other tools
I'll probably just stick with the blue + 2 until further research is conducted. Too bad Patty isn't around too often. I bet she's hot!
Springs in the attic? Wow! Mine are in the hatch with my tire iron and other tools
Thanks for doing the testing. I have some bolt ons and recently added the SU TMIC. I have been running the blue spring, I think tomorrow I'll add the 2 shims and give it a try. Thanks again.
OT: I noticed you have the OBX boost tubes. Where do you get them?
The 2 shims might give you the pre load you need to keep the valve closed while boost is building and the lighter spring should allow the valve to open quicker when it's needed. Just a theory.
Hmm maybe you are right. Rotus8 and F430Tech were doing some nice experiments with the different spring configurations. As noted earlier in this thread, that kind of stopped. I believe it was Rotus8 who was very happy with the Yellow + shims. Personally, I feel the car runs fantastic with my mods and the Forge blue + 2 shims, but I don't want compressor surge if that's what it is.
I'll probably just stick with the blue + 2 until further research is conducted. Too bad Patty isn't around too often. I bet she's hot!
Springs in the attic? Wow! Mine are in the hatch with my tire iron and other tools
LOL. Patty is a GUY.
LOL !!!!!!
