Thread: Recirculation valves upgrade?

I have a bosch valve on my u13, I would want to run higher boost(12psi-20psi) without having a blow off valve and i dont want a blow-thru setup. so im looking into recirculation valves like this one ex. ESE Tuning - Forge Motorsport - Fast Road Closed Loop Diverter Valve 007PA with Adjustable Vacuum Connection (BLACK)
Why buy a blow-off valve if you have a u12,u13, gtir etc. then vent it into the intake, instead of going with a upgraded recirculation valve.

What would some of you guys go with?

Get a turbo xs rfl-25 recirculating valve. It works great, holds 25psi, and fits in the stock location of the bosch valve! I might even have one for sale....

Why do you need to upgrade?

If you have the valve installed correctly it holds 30psi easily (I see most people install it 90* off which has become the internet standard of doing wrong and it blows open easily). The problem you run into is volume released... If that is your problem you need to upgrade from that size which means you can't use a direct fit valve. My bosch worked fine on several setups I had. Only reason I upgraded was I had problems at higher boost releasing enough volume quick enough. So I had to go larger.

The bosch from what I was told leaks at 17psi+

love the 1dsm bov. stock reliability, no adjustment needed. I remember sport compact did a test of aftermarket and stock bov's and the 1dsm rated high on both the stock and aftermarket list.

Greddy Type-RS with the recirculation fitting. I have used many recirculation valves on my old setup and the type-RS was the only one that did not leak when adjusted properly.

I 2nd the 1G DSM BOV. That's what I'm running.
If you want to be super baller, get the Tial with recirculation housing.

Well wouldn't the obvious solution be to go with a valve that uses boost to keep it closed if you are have a problem with the valve opening under boost. Greddy type-s for the win or a type-rs if you cant find a type-s. And in essence a recirculation valve and bov are exactly the same thing. If you recirculate a bov its the same thing as a recirculation valve. If you let a recirculation valve open to atmosphere it is a blow off valve. Either or it still lets out the excess boost.

In essence they might be, but in practice they are different. A BOV needs to be able to close extremely quickly to prevent (or hopefully mitigate) sucking in air during quick throttle changes and during engine braking. A proper recirculation valve (like the Bosch) does not have to contend with this problem and is able to make due with much less diaphragm or spring opening threshold pressure. This gives the added benefit of faster and earlier opening of the valve at the expense of a longer "open" time and slower closing of the valve. The recirculation valve is better at performing it's main function --eliminating compressor surge-- at the cost of extra piping.

Then again, you can always run a recirculation valve with a breather filter and sort of get the good parts of both (if you're into that sort of thing).

Cliff notes: Recirculation valves are typically open during idle and/or engine braking where as BOVs are not due to different activation pressures.

^^^Most bovs are adjustable and some recirculation valves are adjustable too like the one in question in this thread. The amount of vaccum that the valve is adjusted to open at is where it will open. I guess you don't search much on the forum for bov adjusting but there is a thread somewhere here or on that other forum lol on how to adjust them to recirculate with a hand pump and gauge in Hg so you can adjust exactly when the valve is open. My valve is a type-s and it sits open at idle just like you said about a recirculation. It will blow off slowly or quickly depending how fast I shift. The only things that really matter are that there is no compressor surge, and no boost leaks out so your turbine stays happy