Happy New Year!

Happy New Year everybody! 2012 is here and it’s going to be a good one!

Just a few quick updates for this post…

First things first, sorry for the extreme lack of updates, the MKV front is getting a little older and a little quieter. That’s alright though, the MKV generation of cars has been holding up pretty well. The FSI follower problem has been troublesome for a lucky few and there are various small sensor/peripheral problems (thrust sensor, low pressure fuel pump, pcv and diverter valves etc.)  that owners have had to deal with but overall, the cars have been robust. Maintenance just needs to be kept up to date. I recently rolled past 108,000 miles and the car runs great.

Still coming for the month of January:

The recently mentioned aftermarket cam follower is still awaiting final finishing but the company states that it should be released as soon as this month. This follower is supposed to provide 3x the life of the OEM follower by using a different surface treatment (hard chroming). If the product lives up to its promises, FSI owners can rest just a little bit easier about their cam follower issues.

The Koni Yellow Dampers are holding up well and I think I finally got the rebound settings perfect for the stock springs. When you have adjustable dampers, it’s almost impossible to just pick a setting and not fiddle with them. They tempt you at every corner. I’ll do a write up with the settings soon.

“G” Revision PCV Valve Internals

I opened up my non-functional revision G pcv valve and took a few pictures, enjoy.

Revision G Check Valve - This one is broken

Revision G Diaphragm and Spring

Revision G PCV Internals

Product Reviews

I’ve been slowly reworking over some of the older product posts and turning them into more informative reviews.  They’re being compiled on one page.  Click this link or the link at the top of the header to check them out!

Revision D Diverter Valve – Stock Location

Well it’s official, I’ve gone nuts.  I went back to the stock diverter valve location after all the time I spent thinking about diverter valve relocations.  The mechanical valve was nice but I wanted ECU control.  The ecu controlled relocate was nice but required some rigging to get it to work with the stock intake.  So I’ve gone full circle and landed back at a nearly stock intake system setup.  My stock intake is back in, and the diverter valve is back in its original location.


New piston design

Initial impressions are that the D valve feels better in the stock location than in the relocated position.  Maybe something was leaking?  No logs yet, they will come eventually.  Boost response felt a little “off” with the valve in the relocated position.  It bogged sometimes and the car felt labored in the very low rpms.  The boost ramp up was a little strange, it felt like it would spec too much boost at a low rpm.   I should have run some logs but didn’t think of it at the time.  With the valve in the stock location, boost response feels better and is more linear.

There are a handful of reports stating that the valve does not seal correctly on the FSI, leading to decreased throttle response and delayed boost peak.  The cause was never determined but in most cases the problems were resolved by switching back to a diaphragm version.  It could have resulted from a faulty valve or improper installation.  My valve seals and functions just fine.  The summer heat should really put the valve to the test, we’ll just have to wait and see if it holds up.

I think Volkswagen and Pierburg (manufacturer of the actual valve) have finally come up with a bullet proof solution to an annoying problem (torn diverter valves).  The valve is maintenance free and if it proves reliable, is perfectly fine for a mildly tuned 2.0t.

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.


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.


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.

AWE Diverter Valve Relocation – Review

I recently switched my diverter valve setup from the BSH relocate kit to the AWE stock diverter valve relocate kit.  What’s the difference?  AWE’s kit uses the stock electronic diverter valve instead of a mechanical (Forge) valve as in the BSH kit.  Doing so allows the ECU to control when the valve should be closed and when it should be opened.  Not that I was unhappy with the BSH kit.  Not at all.  It’s a great setup, but I wanted to use the revision D valve in a relocate.


Enter the AWE kit.  This is a very well done kit.  Very simple and rather ingenious.  I’m impressed with the execution.  This, in my opinion of course, has to be the easiest relocate setup to install.  The parts are all of very high quality and fit precisely.  I did break the larger hose clamp.  I probably over tightened it but it may be something to keep an eye on.  This kit does not include a diverter valve.  You either reuse your stock one or purchase a revision D valve to go with it.  I did the latter.  The stock intake will not work with this kit unless you have the TSI motor.  You will need to have an intake with a diameter of 2.75 inches.  No worries as this is a very common intake size.  Just be sure to check.  The valve adapter is an anodized piece and works with any oem valve.  The firewall gasket is what you will not find on most other relocation setups.  It’s an oem part but the fact that AWE included it for convenience is very cool.  Silicone hoses are pretty much standard, if not a little thicker than the silicone BSH uses.  This kit is for all intents invisible to the untrained eye.  Just about the only visible aspect will be your aftermarket intake and the one piece of silicone that leads to the noise pipe.

Stock photo from AWE’s website. I labeled the parts.


The most difficult step when relocating the diverter valve is removing the connection to the noise maker piece underneath the rain tray.  I absolutely hate spring clamps.  Fortunately for me, I did this step when I installed the BSH kit.  AWE’s website has a PDF of all the complete steps.

Other than that, installation is very straightforward.  A 1/4 inch rachet and socket set will help make everything go smoothly when removing the stock diverter valve.  The diverter valve bolts are a 5mm hex.  A needle nose vice grip will also help with the spring clamps.  Nothing too tricky on the tool side.  Just be sure to have all your tools lined up beforehand.

Revision D Valve and Adapter

Driving Impressions

So far I have not noticed much of a difference from the BSH kit, as you would expect.  This kit is definitely quieter and I do somewhat miss the noise of the gigantic Forge valve.  I feel like the boost comes on differently but I can’t validate it without doing logs.  It feels like it comes on a little less progressively.  This could be due to the way the ECU operates the diverter valve.  Under most conditions the stock valve is closed, unlike the mechanical valve which is open under vacuum.  This doesn’t allow the engine to draw air through the noise pipe as often as the BSH kit does.  I would give a very slight edge to the purely mechanical setup in terms of throttle response.  Other than that, little difference from the BSH kit.

Why should you get this?

It all depends on what you want.  If you want the ECU to maintain full control, get AWE’s kit.  I suggest picking up a revision D valve to run with it.  If you want a mechanical setup, and especially if you have the BSH intake, go with the BSH.  I would recommend the BSH kit only with their own intake.  The ports are all matched up and you don’t have to cut anything.  BSH might be phasing out the standalone version of their kit, I haven’t seen it on their website lately.  I’m sure they still have it but you have to place a phone call.

AWE can also equip the kit to work with a mechanical valve but I can’t comment on how that performs.  I assume it will work similarly to the BSH kit in terms of mechanical valve throttle response.


I really like this kit.  Clean installation, great design, and relatively cheap compared to the other relocates.  It is practically indestructible with the D valve.  It also maintains ECU control.

This kit is highly recommended.

Noisepipe to turbo inlet coupler connection

BSH True Seal Intake

Original article circa summer ’09 – I’ve split the article into its two components: the intake and the diverter valve kit.

This kit is for the 2.0 T FSI engine.

I received this intake kit awhile ago.  The design is top notch and well made.  It includes single piece piping, a heat shield, a proprietary filter, a Forge diverter valve and all necessary clamps and hoses.  Installation is relatively simple if you have the proper tools.  One highly recommended tool is a hose clamp remover.  I think the newer kits are being shipped with them.

After a few months with this kit, I feel that this is the best intake for the GTI out there right now.  It solves the issue of failed diverter valves and relocates the valve itself to the front of the car.  No dyno runs on the intake yet but midrange and the top end feel better.  The torque curve seems to have shifted slightly to the right, but nothing crazy.  This intake is not very loud, if you are looking for noise, look elsewhere.  Otherwise, it’s a nicely designed piece and a great company to deal with.

If you are chipped, you don’t have to worry about any more torn diverter valves.

Review Redux: updated (1/27/2011)

The BSH Trueseal intake for the FSI engine is just one of many intake systems available for the GTI.  There isn’t much deviation as far as filters on a stick go but this one offers a few unique features of its own.  It offers a built in relocation bung as well as a heat shield which isolates the filter from the engine bay.


Sorry for the horrible picture, a much nicer one will be up soon, I promise

The intake itself is very simple with 2.75 inch piping in powder coat black.  The heat shield is relatively thick sheetmetal, also powder coated black.  The edges of the heat shield are covered with a rubber seal that presses up against the hood liner, thus creating a box around the filter.  The silicone and associated clamps are all high quality pieces.  The filter is a proprietary specification that is narrower than most other filters in order to fit into the heat box.  Despite that, a similarly sized filter from another vendor will most likely fit.  It is oiled but I have not had any problems with the oil contaminating the maf sensor.  It has since been changed out for an AEM Dryflow filter which filters better and requires no oil.

I can’t really comment of how much power this intake makes as I have not put my car on the dyno with it.  You’ll probably gain a few horses, nothing to write home about.  Those gains will increase as you pile the mods on though, especially with chipping.  Just don’t believe the +15 hp ads that you see regarding intakes.  It does wake up the engine a little on the high end and provides a very nice sound.  It’s not loud by any means, so if noise is what you want, look elsewhere.  BSH’s intake provides a very mature sound, no doubt due to the heat shield surrounding the filter.

Here’s something important, and since it’s important, it’s going to get its own break.  MAF sensor placement is very sensitive on these cars.  Some intakes will drive the sensor nuts and in turn your car, causing all sorts of chaos.  Fuel trims are adversely affected by incorrect maf calibration.  STFT and LTFT (short term and long term fuel trim) will be incorrect if the maf placement on the intake is off.  There was an early run of BSH intakes that had incorrect maf holders.  The fuel trims are not too bad on these early intakes but in reality you want it to be as close to zero as possible.  If you buy used, be sure to know which version you are getting.  The older maf holder sticks out about an inch or more from the intake.  The newer ones are much closer to the piping.  Reference the following picture of the older MAF holder:

The newer one is much smaller than that.

Older BSH MAF Holder

Finish is not BSH’s strong suit.  The intake is well made and will hold up but doesn’t look the part.  I know it’s nitpicking but it’s all part of the show.  The welds on the intake are very visible and lend a homebrew look to the whole thing.  The relocate bung is sealed with an ugly vinyl cap if you’re not using it.  The rubber seal on the heat box looks like it came straight from your local hardware store.  The intake also doesn’t secure too well in the box.  I eventually added additional rubber to secure it.  There is certainly none of the flash you get from other manufacturers such as AWE, Eurojet, Forge and APR.  If you’re looking for flashy, this isn’t the intake you’re looking for.  For those that are looking for functional bits, this is it.  It has a great heat shield, a built in relocation port and all the growl a normal adult needs.  Despite the visual flaws, the BSH intake still gets a recommendation from me.  It is priced far below the other premium intake options such as the Forge Twintake, and AWE carbon intake and works just as well.

~ 270 from BSHspeedshop.com and other dealers

Here’s a link to an AEM Dryflow filter that fits in the BSH heat shield.  The fit is a little tight though.  AEM Dryflow

AWE Diverter Valve Relocate – A Few Quick Notes

I’ve had a few days with the AWE Diverter Valve Relocate and here are a few quick impressions:

  • Very quiet with the revision D diverter valve
  • Simple and clean installation
  • Works with any 2.75″ aftermarket intakes or stock TSI intake
  • Boost with the electronic diverter valve feels less linear than the BSH mechanical valve solution
  • Cheapest relocate solution

I’ll have more to say on it one I have spend some more time with the kit.

*Review Posted Here: AWE Diverter Valve Relocation Review*

Revision D Diverter Valve

Part Number 06H 145 710 D


A little while ago, VW released a revised version of the infamous diverter valve.  Now known as the revision D valve, it replaces the diaphragm seal with a much stronger piston type.  Previous revisions (B, C, and G) had diaphragms that were known for ripping and subsequently failing to hold boost.  Some of these failures were under stock boost levels.  The G version is the stoutest of the diaphragm valves with fewer failures reported across the forums.

Of course luck plays a huge role in this.  Some people have reached 30,000 miles on the stock C valve.  I reached at least 45,000 miles on my C valve.  Then again, I tend not to use my right foot aggressively.  If you feel that your car is losing power or making funky noises, pull the valve to check.  Look for tears in the diaphragm.  If you have a boost gauge, it’s even easier for you.  The car will not hold peak boost easily or at all.

The new valve simply bolts right up to where the old one sits.  It seems to have a good track record at the forums.  There has been a report or two of it failing but the causes were unknown.  Maybe a factory defect?  MJM Autohaus currently (1/19/2011) has the best price at $65 shipped.

There are several kits that solve the diaphragm problem by using a piston type mechanical valve, or a vacuum actuated diaphragm valve.  BSH, Eurojet and AWE all sell mechanical kits.  Forge sells one that has ecu control but still relies on vacuum.  I have the BSH valve relocation myself, a great piece of kit but I wanted to hand control back over to the ECU.

Why try this over a mechanical valve?

  • It allows the ecu to control when and how the valve opens
  • Quicker to open when the throttle is released (mechanical valves rely on vacuum and pressure differential to open up)
  • Cheaper (65-90 dollars and no additional parts required)
  • Less hassle at the dealership (oem part)
  • Maintenance free

New piston design

There are certainly arguments for using a mechanical valve such as the ones included in the BSH diverter valve relocation.  A mechanical valve is simpler and pretty much bulletproof.  There are no electronics to worry about, they just work.  In the case of the 2.0t FSI engine (and TSI as well) the mechanical valve is also open at part throttle (under vacuum).  This allows air to bypass the intercooler and turbo and go straight from the intake to the throttle.  This supposedly leads to smoother throttle transitions.  This only works for mechanical valves used in a relocation kit.  I can’t comment on that, I’ve completely forgotten how the car first felt without the BSH kit.  With the kit on, the car ran perfectly well.  Now the exact amount of benefit this provides is debatable but the logic is sound, path of least resistance.

If you’ve tried the new revision, let me know what you think of it in the comments!

Forge Diverter Valve Picture


Just another picture.  This is a Forge part from the BSH DV kit.  This thing is huge.  And also very well made.