BSH Diverter Valve Kit – Review

 

Forge Diverter Valve

The BSH kit is well spec’d and doesn’t scream aftermarket even with the large Forge valve dominating the view.  Granted it does ruin the illusion with the requirement of an aftermarket intake but it’s forgivable.  BSH had a few performance goals with the installation of the kit:  better part throttle engine response and reliability.  It hit both of these targets.  Lets go into more detail as to how it reaches its goals.

BSH uses the noise pipe as a recirculation pipe, routing to big Forge valve in the front of the engine bay

Better Part Throttle Response

This one seems to baffle people the most.  How can installing a replacement valve result in better response?  To answer that we need to delve into the details of the stock system.  The stock 2.0t diverter valve resides on the compressor housing itself.  This is not a bad design.  It is very efficient in terms of packaging and cost.  No need for extra hoses, pipe and other support hardware.  However, it does require the airflow to go through the intercooler when not under boost.  The BSH kit reroutes the air flow through the stock noise pipe, bypassing the intercooler and routing air straight to the throttle pipe when the engine is not requesting boost.  The mechanical operation of the Forge valve keeps it open under vacuum.  Shorter path for airflow – slightly better part throttle response.  Under boost pressure, the valve is closed and air follows its normal path through the intercooler.

Practically Unbreakable Forge Valve

The Forge valve used in the kit is massive.  It carries 1.5″ ports to match up to the stock noise and throttle pipe inlet/outlet.  The valve controls airflow with piston design instead of the diaphragm stock valves.  (Note that newer D revision valves now use a piston as well)  Constructed out of aluminum, this will last the life of your car and then some.  You can rebuild the valve several times over.  The only downside is that you’ll have to grease the valve occasionally.  Regreasing is a quick procedure that any owner can do at home.  Mechanical valves are also slower to react than electrical, but it seems to be a none issue in this kit.  The vacuum source is provided with a boost tap on the manifold.  Because of the short length of the vacuum hose (less than 5 inches) reaction time is quite quick.

Overall Design

As with most of BSH’s designs, this one isn’t pretty or gussied up.  It’s very functional and to the point.  There are no fancy pieces to decorate the engine bay.  Even the boost tap is anodized black.  You get a few specific silicone hoses and then the shiny Forge valve.  Very clean look overall as it utilizes a few stock components such as the noisepipe and and one of the hoses.  Not fancy, but it gets the job done cleanly.

Installation

The installation is not too difficult.  Follow the instructions on BSH’s site and you should be good.  It requires a few tools so make sure to have those before hand.  Here are a few suggestions though:

-The wipers do not have to be removed to move out the noisemaker/speakerbox.  In fact my wipers were frozen onto the posts.  Just a little careful lifting around the rain tray will help you.  I actually just left it in there and just disconnected the hoses I needed.  You can do that too and it will help when you have to reinstall things back to stock.

-The diverter valve blockoff will require removing the diverter valve bolts which are a 5mm hex.  Use a 1/4″ ratchet with a short extension maybe.  It’ll help immensely.

Other than these few tips, just take your time and don’t rush.  The proper tools help a lot.

Grade?

I really like this kit.  It does it’s job and does it well.  The sound the valve puts out is nice and not too loud.  It’s rather addicting actually.  It has everything you need to put it all together.  It solves your diverter valve issues and provides a nice performance uptick.  The only knock on the kit I can find is that it requires an aftermarket intake.  And if you don’t have the BSH intake with it’s built in bung, you will need to hack off a portion of the rear to fit BSH’s own rear section.  It’s not difficult but other competitors have figured out ways of using your aftermarket intake without cutting.

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