I think my sad little used EvoX BPV has bit the dust. I've always noticed it has a weird sound when trying to hold higher boost (ie higher RPM). I will be installing a boost/wideband gauge soon so I'll be able to see how bad it's leaking (if at all).

That being said, what are some tried and tested BPV's that you have on your cars?

So far, I've been told the Synapse Engineering DV is the best. It's not too costly but curious to see reviews for other ones.

Also keep in mind, I will be doing a CBRD Rad Lite turbo soon so it has to hold 26-28psi (peak) and taper to about 20.

 

I'm leaving on vacation...when I get back I will take it apart and see if it's just clogged or something. Another possibility.

 

TiAL QR (my setup). The Synapse DV is the absolute best thing for the stock RA turbo, however. You will love it.

 

Go fast bits is pretty popular. Works has a pretty nice one as well. Those are what I see most around here.

 

for the money, you can't beat a used EvoX BPV that's been crushed.

 

thats tue

 

I want to buy a BOV this weekend. I looked into a used EVOX, but have had some difficulty locating one, and think I want to go "new" anyways. Considering the $100 price difference, can you help me understand why you think the Synapse is better than say...AMS for example?

 

The AMS BPV is literally just an Evolution IX stocker. Stock BPV's are great, because they "leak" ever so slightly. This allows them to more consistently meter out excess pressure. The boost will still be there, but it won't spike. It will build and peak in a more natural fashion.

If you want a big diaphragm BPV, the TiAL has (I think) the best build quality and has the best track record. It works by letting off excess pressure all at once. This is what the GoFastBits, TurboXS, etc. BPV's are. Some are slightly more sensitive than the TiAL, but I have a feeling that a different spring would solve this problem. It doesn't open and close the fastest, but it will hold in boost like no other (not necessarily the best option for a stock turbocharger, as it will promote surge). I use this, but I got a good deal on it.

The Synapse works in completely a different way. It is not actuated in the same way that a normal diaphragm BPV is. It is the fastest opening and closing thing currently on the market (by 100x or so). It builds and releases pressure similar to the way in which a stock BPV would, but it isn't leaky. It is accurate. It prevents even miniscule surges. It opens and closes faster than you would even notice a turbocharger surge has even occurred. The TiAL will let you know, as it makes a rather unnerving sound. The Synapse smooths out the curve of boost delivery.

My conception of BPV dynamics may be slightly incorrect, and I apologize for that. That is just how I perceive that they work after examining countless threads on this site and many others. I hope that that was helpful, though.

 

The other thing is be careful when upgrading your BPV and using an "off-the-shelf" tune. As I understand it, if you have a map designed for stock BPV and upgrade to a diaphragm unit, then you will tend to ride the left side of your fuel map. Basically, this can be bad. I may be using the wrong word to describe what is happening with the turbocharger, as well. The problem with excess pressure is that it finds its way back to the turbocharger and pushes on it in the wrong direction. This can kill a turbocharger.

Also, do not cheap out on the BPV. If you buy a good one, it will be with you for a long time. Mine is on car number two.

 

I use the TurboSmart, and absolutely love it. The ability to change from hard to soft is pretty cool too.