ABARTH Fiat Uno Turbo Club of South Africa

Fitting a bleed valve

DIY / Small Upgrades

Fitting a bleed valve

Remove the following to gain access to the turbo actuator hose:

  • The intake hose to the airflow meter
  • The hose from the airflow from the airflow meter to the turbo intake
  • The joining hose and metal pipe from the turbo to the intercooler
  • The bypass valve (dump valve)
  • The airflow meter itself
  • Disconnect the wires to the boost cut-out switch
  • The injector cooling fan and its pipework

Once these items have been removed the turbo actuator and the short rubber hose will be visible and accessible.

The first thing to do is loosen the jubilee clip in order to remove the turbo intake hose from the airflow meter; you will need to do this in order to have enough space to work.

You should replace the original short hose with a longer hose, long enough to fit a bleed valve in a position, so that later, it can be adjusted; the length of the hose installed should be approximately 3ft in length.

Once the bleed valve has been fitted, refit all the hoses in the reverse order. To begin with, the bleed valve should be closed. Remove the injector cooling fan, as this never comes on and is about as useful as a chocolate teapot; remove these items and the engine will be less cluttered.

When it comes to refitting the wires to the maximum boost pressure switch – don’t.

Also while you are there you may as well fit a sports air filter as you will not only make lots of space, your Uno will breathe better.

Once everything has been refitted, your car should start as it would normally.

If everything is OK, move on the next step; it involves adjusting the boost pressure by opening up the bleed valve. Under normal circumstances a standard Uno Turbo will never exceed 0.75 bar boost on the gauge, open the bleed a fraction and take the car for a test drive, pick a quiet road because you must concentrate on what boost the engine runs.

You aim to achieve 1.0 bar or 14.7 psi boost and no more, which the engine will achieve in 4th or 5th gear at approx 3500 rpm under full throttle, above that the boost will start to drop, because the standard turbo isn’t big enough to deliver high boost at high engine rpm, you will probably find that the boost level at 6000 rpm drops down to 0.75 bar.

It also very wise, to take the car to a rolling road dyno to confirm that engine is not running too lean at full power and at the same time the reading will tell you how much power you now have :-)