Ten years ago, I had an Eclipse GSX. Loved that car. Between the TurboXs RFL BOV and an atmospheric o2 dump, that car would terrify children and small animals. Im older now and a bit more refined, just like the Evo is to the GSX, so I wanted something a little more low key. Enter the TurboXs Hybrid BOV.

There are a few hybrid valves on the market that have a few small exhaust ports vented to atmosphere as well as the exhaust port that connects to the intake. My previous experiences with TurboXs led me to theirs.

http://www.flickr.com/photos/13891619@N00/5928592424/http://www.flickr.com/photos/13891619@N00/5928592424/ by http://www.flickr.com/people/13891619@N00/, on Flickr

The RFL for the GSX had an install kit that provided a mounting flange for attaching to the stock UICP. For the Evo, there isnt really a need for a kit as the valve ships with 2 weld-on adapters. The weld-on adapters provide enough exposed pipe to secure the hose clamp. Im going to suggest they provide an Evo specific adapter that is a little longer and a little thicker with a lip at the end. Id feel a little more comfortable that way. The clamps are holding just fine at stock boost levels. I plan to up the boost a pound or two in the future. We will have to see how things go then.

Here is a shot of the HBOV next to the stock unit.

http://www.flickr.com/photos/13891619@N00/5928033867/http://www.flickr.com/photos/13891619@N00/5928033867/ by http://www.flickr.com/people/13891619@N00/, on Flickr

Install was simple. Since I had already done the ETS intake, all I had to do was remove the hose clamps on the two BOV hoses and insert the TXS unit.

Installed pic here:

http://www.flickr.com/photos/13891619@N00/5928030905/http://www.flickr.com/photos/13891619@N00/5928030905/ by http://www.flickr.com/people/13891619@N00/, on Flickr

I was a little concerned about hood clearance at first, but have not had any issues. Any rubbing would be apparent on the hose as it would get pinched between the nipple and the hood. Ill keep an eye on it, but it looks fine.

The stock valve is open at idle. Since the HBOV vents (partially) to atmosphere, you need the HBOV closed at idle. No problems with this right out of the box. The valve comes with a set of washers that you can use to preload the spring but I have not used any at this point. I figure, from a drivability perspective, the less load on the spring the more responsive the valve will be.

My main concern with valve response is when you are on the throttle and making boost and then back off the throttle some, keeping the throttle body open somewhat but not enough to make boost. If the valve is not responsive enough, you will experience compressor surge in this situation. If you back off the throttle entirely, the vacuum condition will make sure the valve opens even if the spring is heavily loaded. So far so good. Without any adjustment, the valve stays closed at idle and still opens in the partial boost situations. Im very pleased with the results.

Here is a link to a video of the HBOV in action. This is just idle revving, so you dont get the full effect but its a good indicator of the tone/pitch of the unit. It sounds a lot better when driving since you are releasing so much pressure. Im very happy with it.


If you are doing a serious performance build with the stock air flow meter, sticking to a unit that is fully recirculated is your best bet. If you are like me and have reasonable power goals (sticking with stock turbo, not planning on clearing 350whp/tq) and want to add some show to your ride, this is a good choice.

 

nice review and sound clip!

 

looks to me like your vaccum line is pinched right at the nipple.

 

Its not pinched, but its definitely tighter than I would like. I didnt trim it very well when I did the ETS intake installation.

 

im contemplating picking one up myself, you will have to let me know how it ends up after running it a little while

 

ive herd about this one dose any one know how well it stands up against HKS ?