Tekst na engleskom koji se bavi modifikacijama Una Turba. Dok sam vozio ovaj automobil ovaj tekst mi je bio koristan pa ga ću ga podeliti sa onima koje ta tema zanima. Tekst je preuzet sa (sada neaktivnog) sajta www.unoturbo.co.za

UNO TURBO; BASIC ENGINE BOOST UPGRADE

Hi there everyone.

As promised long ago, I have got round to writing an article on how to modify your Uno Turbo. In order to keep things simple, cost effective and reliable this article will show an uno engine a modified air filter arrangement, and how to raise the boost.

Above you can see the picture of a standard uno engine bay; you will have to remove the following items 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 or recirculation valve (same as a dump valve)
The airflow meter itself
Disconnect the wires to the maximum pressure sensor
The injector cooling fan and its associated trunking
Once these items have been removed the turbo actuator and the short rubber hose will be visible and accessible.

Above you on the left you can see a photograph of the turbo actuator and the hose, on the photo you can see hoseclip being loosened 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.

Also above on the right you can see a picture of the bypass valve, this item is a dump valve that releases the excess boost pressure when close the throttle back to inlet of the turbocharger, instead of releasing the excess charge to the atmosphere like the aftermarket dump valves you can buy, On the Uno Turbo there is no need to fit an aftermarket dump valve because as you can see Fiat had the good sense to fit one as standard unlike Renault on 5 GT turbo or Ford on the Escort and Fiesta RS Turbo.

You should replace the original short hose with a longer hose, long enough to fit a bleed valve in position that at later moment can be adjusted, so the length of the hose installed should be aprox. 1 meter length. you can fit a shorter one but access to the bleed valve will be more difficult.

Once the bleed valve has been fitted, refit all the hoses in the reverse order, taking care to make sure that that they are securely fitted. To begin with the bleed valve should closed, also those who haven’t removed the injector cooling fan, and the shroud under the plenum chamber should take the opportunity to do so now, as this never comes on and is about as useful as an ashtray on a motorbike, as Collin Chapman used to say „Never give a washer a free ride“, after you have removed these items the engine will considerably less cluttered.

When it comes to refitting the wires to the maximum boost pressure switch don’t, just insulate the terminals with tape so they touch each other and secure with a tie rap somewhere.

Also at this stage whilst refitting things, its a good idea to fit a direct induction airfilter and remove the airfilter box and the pipe that goes across and above the radiator, again this will help unclutter the engine bay and make future servicing and repairs easier.

Recommended things to do at this stage is to replace the spark plugs with triple electrode one from NGK, model BCP7 ET, check the condition of the distributor cap and rotor arm and replace if they show signs of excessive wear.

Once everything has been refitted, your car should start as it would normally, take the car for a short test drive to ensure everything is order, it shouldn’t feel much different at this stage except that you will have a bit more induction engine noise. If everything is ok, we move on the next step, which involves adjusting the boost by opening up the bleed valve. Under normal circumstances a standard Uno turbo will never exceed 0.5 bar boost on the gauge, open the bleed a fraction and take the car for a test drive, pick a quiet road because your attention should centered on what boost the engine runs.

You aim to achieve 1.0 bar boost and no more! which the engine will achieve in 4th or 5th gear at aprox 3500 rpm under full throttle, above that the boost will start to drop, this is normal with the 1300 Uno turbo, 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. However tempting it is to raise the boost further do not do so, as the fuel injection system in standard form can not cope with more boost, and your engine will run lean with serious risk of damage. You have been warned !!

With these modifications if your engine is in good order it will develop approximately 125bhp, a little bit more if you fit a performance exhaust system. These are real horsepower figures and not the bullshit and exaggerated claims you will come across in many magazines adverts.

It also very wise, to take the car to a rolling road to confirm that engine is not running too lean at full power and at the same time the will tell you how much power you engine develops.

I should also warn you that this modification also increases the torque output of the engine, and if your clutch is worn and on its last legs, by raising the boost it is quite possible that it will slip, if this is the case reduce boost pressure until it stops slipping and organise Having a replacement fitted.

The author is not responsible for any damage that may occur as a result of carrying out these modifications, the owners do so at their own risk! I have modified quite a few Unos as described in this article without a problem but as I cant personally check the modifications that each of you carry out, I cant be held responsible.

4/12/98

e-mail Joe at jrturbo@activanet.es