Ive done some research on bov's. there is a few i like, but alot have compression surge. but why is compression surge so bad. i know its bad for the turbo but what does it do to it that is so bad. i haven't been able to find anything.

anybody have any luck with duel port bov. where half recirculates and the other half gos to atmosphere.

 

Im not sure if your referring to surge when u let off, or surge upon fulll boost, but I have read quite a few of threads just like this one, and there arent too many diffinitve answers as to what is "causing" the compressor surge, upon full boost, (unless I REALLY am on the left hand side of the surge line) but if your referring to when you let off the gas, the BOV, needs adjustment...

(just in case u have the same issue I do)
I have slight "compressor surge" upon doing pulls from low rpms, right before full boost, but not if I start above 3000rpm... I bought a used APS bov, which is a dual vent, in hopes that this would solve the issue, (thinking it was a leaky stock bov) but it did not... It did make it slightly better, but still does it.
*But w/ the APS, now Im seeing the WB going WAY rich in between shifts (normal driving)

From what Ive gathered, there are 3 things that would cause this kind of compressor surge...

1. Boost leak

2. Leaky BOV, which in turn is a boost leak.

3. wastgate needs adjusting.

I already had the wastegate arm tightened up a couple turns, but still does it... Maybe a couple more... IDK

GL

 

2nd that ^ Check for boost leaks for sure, any little one will cause part throttle flutter of the BOV.

 

most common cause of compressor surge is too stiff of a blow off valve spring...

compressor surge wont ruin your turbo or your car. i have run a stiff BOV spring cause i run high boost. so at normal driving i have compressor surge all the time. i been driving the car for over 2 years like this and have never had one problem cause of it. turbo is in perfect condition. so i wouldnt worry too much over it happening

 

i'm running the stock bov now. im looking at getting a new one. but alot of videos ive been watching have compression sugre. i personally think it sound sick and i was wondering what it does to the turbo thats so bad. EvoJoeIX said it doen't do anything any body can second that

 

u still havent stated when this surging is happening... This will help in what needs to be done!

Im assuming your surging prior to full boost (like me) cause the stock bov shouldnt surge on lift off.

I believe evojoe was describing the effects of having too stiff of a spring in an aftermarket BOV, which causes compressor surge while, just "cruising". My APS did this as well, when I had the adjustment screw too tight. This, while cruising *shouldnt* be detrimental to the lifesapan of the turbo, cause its barely seeing any boost.
Just sounds and feels like ****!

 

yea my BOV isnt stock

 

From my experience with my old Subbie, the BOV wasn't really worth getting. If you are interested however, check out Gofastbits. They make adjustable ones. I had the Deceptor Pro that you could control from the inside of the car. You can actually change it to 100% atmospheric or to bypass 50/50... whatever you want. Just fyi if you like the sound but are concerned about the MAF readings ect.. my tuner for that car tuned out any compression surge. Edit : posted the website below, it's worth a look.

http://www.gfb.com.au/

 

Too stiff of a spring in the BOV will do it, also the compressor cover on the turbo can cause surge. This is why FP came out with those huge anti-surge ports to reduce the "bucking" that you can experience during full spool up.

I had the APS Twin Vent BOV and still had the compressor surge, so I upgraded to the new TiAl Q Recirculating BOV and it is smooth as anything I have ever driven. Definitely worth the money. TiAl quality with the recirculating the stock MAF needs...