Ej206 wont hit target boost

For the older twin turbo B4 models

Ej206 wont hit target boost

Postby Blury » Fri May 08, 2026 12:59 pm

2000 subaru legacy be5 Blitzen located in New Zealand. My car has been tuned by CCT Auckland car is set to 17psi and wont go over 11psi ish. Pulled vacuum hose off primary wastegate actuator to make it free boost no change at all. Have done the basic checks vacuum hoses smoke test read codes everything seems fine just not enough boost!. I have removed the wastegate actuator on the VF25 and the wastegate flap only moves like 20 degrees each way and i can not get it to go further. Any help is much appreciated.
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Re: Ej206 wont hit target boost

Postby bigBADbenny » Fri May 15, 2026 8:51 am

Get a bicycle hand pump with gauge, a mattress adaptor, gently pump up your wastegate actuator, at what pressure does it open? That’s your wastegate gate pressure.

If the wastegate doesn’t open at the required pressure, or if the wastegate diaphragm leaks, replace or recondition the faulty parts.

To test wastegate pressure whilst driving, connect the turbo outlet pressure reference port directly to the wastegate actuator pressure port using a piece of hose with no restrictor inside.

You should achieve boost at wastegate pressure. Avoid unrestricted boost tests as you may damage your turbo via excessive shaft speed etc.
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