lovemyseven

iTrader: (2)

I think I may have some compressor surge taking place. I have an aftermarket apexi BOV which was custom welded to my IC piping. I don't intend on removing it. What to do? Can I modify my BOV? Should I add another one, possibly the stock bov, and attach it to the small diameter outlet off of the intake elbow just before the throttle body? What are the dangers of compressor surge?
Also, beware of Rotary Performance! Chris, who owns the joint told me the noise was nothing to worry about. I told them that I had heard that it was compressor surge and he told me no, it's just your blow off valve making a funny noise. It's all about the dollars with these guys so owners beware. 15 +years in the business, he should know in a heartbeat what the noise is, and tell his customer about it, the dangers of it, and how to prevent it. I also told him that I had heard that my Apexi BOV wasn't a good unit, and he told me that they are all the same. Beware who you trust with your car.

Wargasm

I have an Apexi BOV as well... only 1500 miles on it, and I THINK that I have the same problem that you do. (I'm not sure how many different models they sell; mine is the one that comes with the XS Eng turbo kit)

I went out today and noticed that instead of the usual smooth PSssshhhhhhh sound when I let off the gas I get a SHH-SHH-SHH noise. I immediately thought "It's the BOV" when I heard it.

Anyhow, I took it apart tonight and there is some goo/dirt on the shaft inside that -might- have been keeping it from opening right. I will clean and test it ASAP. Maybe tomorrow depending on the weather. I will post back here with my results.

Brian

AJC13B

So what actually happens?

After you back off, do you hear the BOV pssh and then a noise like csh csh csh or something?

If you do (**** poor example I know) then it isn't much to worry about. It is compressor surge, but isn't that bad. You may find putting another BOV on will get rid of the problem as it usually happens when your BOV can't vent the required air and some still pushes back through the blades of the turbo.

RETed

If your BOV has a tension adjustment, back it out as much as possible.&nbsp This lets the BOV open earlier/quicker.


-Ted

newRX7fan

iTrader: (1)

I think AJC may have gotten it right. I have the XS turbo kit also with the Apex BOV and it works the same- some psssh and then some csh csh csh. I may change over to an HKS racing BOV since I can get one for free and it should work better, not that there's anything really wrong with this one, just I don't like it making the goofy sounds.

Wargasm

OK...

I cleaned the shaft inside my BOV today (see above post for more info) and put a light coat of oil on the internals and reinstalled it.

No more SH SH SH noise.

To clarify further for the other poster, I used to get a clean PSsshhhhhh noise... then it went to a SH SH SH noise. Now I've got just one PSshhhh again. If that makes any sense you are inhaling too many fumes from the garage!

Brian

13BAce

I get the same thing, but I definitely hear the 2nd sound coming from my turbo. I have a small Greddy Type S. I've been meaning to add a bigger Type R for about 9 months. I'll try to do it this weekend.

lovemyseven

iTrader: (2)

If you are using the stock intake elbow that attaches to the throttle body, there is a outlet on it where a hose connects. What about plugging the hose, and placing a stock BOV there to help out?

AJatx

iTrader: (1)

Check the BOV to see if it's stuck or hard to move valve open, like Wargasm.

You can also check to see if you have a good vacuum source for the BOV. My buddy had a bad silicon vacuum hose (dunno how since it was new?? but I didn't do the install) that caused the valve to be stuck closed.

Last thing to check is the tension of the valve itself. Turbo Xcess has shimmies and others have a screw type of adjuster for the spring tension.

J

lovemyseven

iTrader: (2)

thanks,