DV Spacer – Continued

Background:

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

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.

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.

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.

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.

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“.

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:

• DV Spacer first investigation
• ECS DV Spacer product description (view at your own risk)