yep. and the reason a stock car doesn't do that is because the stock BOV will open under those conditions.

 

Had exact same problem with exact same BOV talked about in this thread. Went through a handful of springs, then even cut the springs. Sold it.

 

well, it leaks

 

the problem isn't with the bov it would be doing the exact same thing if there were no bov on the car at all

 

I just don't think that people physically understand that the turbo is pushing more air than can fit through a partially opening or closing throttle body.

It doesn't really matter though as the OP does not tune his car...

 

agreeeeeeeed

Annnddd a stocj dv is designed around practical driving necessity. A tial doesnt leak, but maybe it should. Lol. Cold side control is as legitimate as hotside control. People get their panties in a bunch when people talk about dv/bov leaking but we have already established in this thread that leaking under certain conditions works best. Look at 94awdcoupe started a thread on the type s. I wholeheartedly agree with him on that topic.


Yup same train of thought.

 

ecu boost can cause that, so can bov, so can internal wastegate preloaded to much.. i can make my car do that if i preload the wastegate to tight on the dbb turbo + 2.3 setup..

if its tune related its super easy to fix if you understand how ecu boost all works..

that aside, thanks for that info acepitcher, im on the stock ported also.. that's reassuring to me.

 

^this.

All I know is the TIAL Q that I own with a -3psi spring (special order only, hot pink paint on it) on it is the best BOV i've used. No leaks and great driveablity. Take that same BOV and put a -11psi spring in it and the driveablity SUCKS!

the above obviously doesn't work if you're using a vta bov with a MAF.

 

You can sit and lightly free rev the car and get a Tial BOV to do the exact same thing.

When it does it, you will SEE the BOV valve boucing ever so slightly on the seat. That is BOV flutter.
Other then it being annoying, it's not going to hurt anything.

With a MAF on the car, that type of flutter would cause my car to go ridiculously rich and stumble. On speed density, it makes the same noise, but the car doesn't stumble at all and AFRs stay rock solid.

ANY BOV venting to atmosphere on a MAF will have the same issues.

 

This is consistent with the single spring mod in other types. Lol proven to work, and if recirculating works good too. SD does fix a lot of drivability quirks but isnt for everyone or even an X at this point.

 

damn, that's the first thing I've heard that makes me want SD. I need to re-research why i decided i didn't want it again... well, maybe first try a different spring in the Tial

 

Just try the next lightest spring, or buy them all. You want the bov opening slight at part throttle. You also must have it recirculated on maf.

You want it opening at part throttle for the reason that wingless pointed out.