DV Spacer – Continued

Background:

Problems caused by the DV spacer are legendary, kind of like Bigfoot.

Searching for Bigfoot

Some people have reported issues resulting when they install the DV spacer.

I looked into the subject almost a year ago and didn’t find that the device caused any problems.

I’ve had an ad up on the Facebook Marketplace for almost half a year trying to buy one of the leaking DV spacers, but nobody has offered to sell one.

DV Spacer Function:

While swapping some parts related to the Mk8 PCV I reinstalled the DV spacer (non-leaking) that I have.

DV Spacer Reinstall
DV Spacer Reinstall

As a refresher on what this spacer does, normally when the diverter valve (DV) opens air is discharged into the intake through an opening in the compressor housing, as shown by the arrow in the image below.

Turbo Housing DV Passage
Turbo Housing DV Passage

The DV spacer blocks this passageway and redirects the escaping air outside the intake, this opening is identified in the image below with the arrow.

DV Spacer Opening
DV Spacer Opening

With air venting outside the intake rather than inside the sound of air escaping is louder.

That’s it. It does nothing else.

As I covered in the previous post, some people have attributed all sorts of problems to this part, most often that it causes boost leaks.

More Data:

I logged the DV position as the ECU commands it to open and close and plotted this information along with the pedal position, boost pressure, and engine RPM.

This was done with the DV spacer installed, and with it removed.

ECS DV Spacer Installed
ECS DV Spacer Installed

The chart below shows the DV Spacer installed and it can be seen that as the throttle position is opening, engine speed is increasing, and boost is building.

About halfway across the chart, a vertical red line shows up: the ECU opening the diverter valve.

When the diverter valve opens and air escapes through the DV spacer an audible sound can be heard. The famous DV spacer boost leak – except it is an intentional release of air by the engine computer.

Note: Some enthusiasts have argued that this intentional release of air is the boost leak. I ascribe to the more common meaning of a “leak” being a fault or mistake, not on purpose.

Stock DV – With Spacer

The next chart shows a similar situation with the DV spacer removed.

The throttle plate is fully opened while engine RPM and boost pressure are building.

Then about three-quarters of the way across the chart the ECU opens the diverter valve, even though the throttle plate remains fully opened. Same as when the DV spacer is installed.

The difference now is that the air flows to a location inside the intake where the sound is muffled and the driver is unaware of the “boost leak“.

Stock DV – No Spacer

Conclusion:

After installing a DV Spacer the GTI was logged and it was found that the ECU opened the valve at times when the throttle plate was fully, or nearly fully, opened, and boost pressure and engine speed were increasing.

This result was also observed when the DV Spacer was removed.

No evidence has been found that would indicate that a DV Spacer causes a boost leak or any other problem. The search for Bigfoot continues.

References:

8 thoughts on “DV Spacer – Continued”

  1. I ran one for a few mos….nice noise makers. For the life of me I don’t understand how folks think these cause any issues. That missing puff of air in front of the turbo is doing nothing w/r to the time it takes to build boost but folks will swear up and down it causes issues. MK7 kids are so silly haha

  2. I know a guy who runs the dual port one that bolts right up. Not sure how much his is set to vent. But with the eqt ots tune, he’s never reported an issue on his R

    1. Jeffrey Jones

      I’d be surprised if anyone that has reported an issue took the time to log their car to determine if it was a real issue. I’ve watched the comments for a couple of years and every instance of a reported problem was anecdotal.

  3. crussell126

    When I bought my car used, it came with a Torque solutions dv spacer on it. Never seemed to have any issues with it leaking boost but due to the design of it having 3 gigantic cutouts I did end up having it spray oil from the pcv system all over my turbo and engine bay. I’ve since removed it and I should still have it, I would be more than happy to send it your way if you’re interested in having it.

    1. Jeffrey Jones

      Thanks, since it was working correctly there wouldn’t be anything new for me to look into with it.
      Were you using the stock TIP or aftermarket?

  4. crussell126

    I had the stock TIP on for the vast majority of the time that the spacer was present on my car, but I believe there may have been some overlap in-between installing the 034 TIP and removing the spacer. Unsure tbh as it was at least a year or two ago now. Also on the stock Mk7 PCV in case that’s important

  5. Hi Jeff,

    Any idea why the ECU was opening the DV non-intuitively?

    The only reason I can think of it being part of the boost control strategy (in tandem with the wastegate) or air-fuel control/EGT control?

    It would be interesting to see some plots of the DV duty cycle against things like boost pressure, target AFR/O2 and maybe EGT (if this is available).

    Thanks.

    1. My guess is that at lower air flow rates the turbo is less responsive to change requests, so the strategy for keeping it spinning faster without supplying excess air is to bleed off the excess through the DV. That should shorten the response time if the driver requests more power.

Leave a Reply