Hi All,

So I decided I needed an aftermarket BOV since the stock one leaks about 25psi. For my countries law's I required a recirculating BOV, NOT ATMO! So after much deliberation I decided on the Perrin unit.

So Chris@MAPerformance gave me a little discount on this unit and got it to me ASAP! THANKS MAP

My first impressions were:

a) top notch build quality
b) short outlet pipe length!
c) can't see how their unique design offers advertised 190psi boost holding pressure? Since the spring is actually weaker than the stock unit, IE I can push the piston much easier by hand..

Taking off the stock BOV and putting this one was about a 30 minute job.

During the install I made the following observations:

a) thankfully Perrin included a replacement vacuum hose since the stock one is a bit too short
b) unfortunatley they didn't include any hose clamps for it, luckily I had some zip ties floating around
c) as suspected the outlet pipe length really is an issue, it seems to be about 5-10mm too short, I don't feel like I got a GOOD hose clamp on it, which if it comes off WILL be disastrous!!! Perrin if your reading this please fix!!!!

As per the instructions I left the BOV with the factory adjustments, i had it configured as "boost ON piston", and went for a drive.

Immediatley I noticed a slight clinking metal-on-metal noise when lifting off the throttle after boost. It's not very noticable, so you can probably ignore it. I am going to experiment with some foam/tape to see if I can reduce it...

I did a quick log, and boost looks like its a bit higher, I will have a proper before/after boost graph tommorow morning on my way to work :P

If anyone cares to try and explain how Perrin can claim unlimited boost holding then please do so, I am genuinely interested

PRO's
- Construction is A+++, nice materials, nicely machined
- Adjustable
- Perrin Quality
- Slight clinking noise when letting off throttle, I am assuming this is the flow control screw bottoming out on the top of the BOV
- Comes in black too

CON's
- Outlet hole flange is WAY to SHORT!! This needs to be about 10mm longer, otherwise I don't feel I am getting a good grip with the hose clamps
- Slight clinking noise when letting off throttle, I am assuming this is the flow control screw bottoming out on the top of the BOV
- Be nice to include hose clamps for 1/4" hose



Thanks Hollywood_X for the image :P

Cheers
D.

 

Can we get some pics of it installed?

 

The claim that it can hold nearly an unlimited amount of boost is with the valve flipped around the other way, with the boost pressure entering through the short side. With it flipped, the boost pushes on the back of the valve keeping it closed, so essentially the more boost you run, the harder it pushes the valve closed.

 

Sure thing - its dark out now, so i will get it tomorrow morning

 

Quote from their install instructions:

 

Interesting. I have pondered this unit as well. I love perrin products, but unlimited boost is a pretty bold claim.

Please keep us updated as you further test it out.

Bren

 

Oh ok...

Since there's no diaphram, the boost will enter into the top through the vacuum line (inside the chamber where the spring is) and push directly on the back of the valve that way. If the back of the valve has a larger surface area than the face, boost pressure will exert more force on the back and hold it closed. Even if the back of the valve and the face are the same size, the boost pressure pushing in opposites directions will equal out and the spring will still hold it closed. So yes, in theory at least, no matter how much boost you run it'll always stay closed.

 

yeah thats what I am thinking as well...

so it doesn't matter than the amount of air entering the top section is less because of the smaller vacuum line diameter?

 

Hose diameter doesn't matter for static pressure, but it can affect how quickly pressure can build or drop in the chamber. I imagine that the hose diameter is plenty large enough though to accommodate the needed response.

I've been aware of this DV for quite a while but yours is the first review on it. Any flutter in off boost driving?

 

Good info thanks MrFred!

Re Flutter - Not as far as I can tell, but I have only driven a short distance so far... I will post up more tomorrow..

 

You can flip the stock one around too

 

mrfred: Hollywood did a review on the other site. Cliff notes are: Hollywood likes it. (From an engineering standpoint, that means a lot)

 

It's the least I could do sir, thank you for your continued contributions to this community!

 

I've been looking at this valve for sometime but haven't found any reviews. Looking forward for more info and pics.

 

I agree, it'll work the same way...but nobody likes to do that or thinks it'll work properly.