I have a 2008 WRX with the stock TD04 turbo.

I cannot hear any spool up as one would usually expect with a turbocharged vehicle.

Yet i have used an ODBII bluetooth device and torque for android to confirm that ECU see's a change in vacuum / boost.

Is this normal or is there likely a problem.

  • Hmm just found this which suggests it might be normal, clubwrx.net/forums/engine-modifications/…, Would still like an answer from someone who knows their stuff.
    – Aaron Tate
    Commented Aug 15, 2017 at 3:09
  • Were you able to hear it spool up before, and now you can't? Or is this just something you noticed compared to other cars?
    – CharlieRB
    Commented Aug 15, 2017 at 11:42

3 Answers 3


I've owned three different turbocharged Imprezas and can confirm that it's perfectly normal not to hear the turbo spooling up. In fact on a standard WRX if you can hear the turbo spooling that would normally indicate a problem!

If the Torque app is showing the right level of boost then you've got nothing to worry about.


Is there any lag getting boost - if not then the turbo is already up to speed. Designs have changed from the early ones and market forces forced a move away from the boy-racer image requiring the power without the noise....


My 2006 Jeep Liberty CRD with the factory Garrett turbo is not audible until it hits about 10 inches, and my hearing is tested to be acute.

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