Turbo compressors provide artificial ventilation. Things are surprisingly simple in essence. The exhaust fumes turn a paddle wheel. On the shaft of that fan on the other side is a paddle wheel that pushes the air inwards to the combustion chamber. Some forty years ago, the owner of a Fiat 850, who mounted a turbo on his pride, noticed that it was a little less simple. That turbo came from a diesel truck. And the 850 cc block just didn't have enough 'breath' to get things going.
Some more professional tuners achieved impressive power increases with a solid 'but'. Because when the turbo came into its working area, the increase in power was so sudden and strong that less talented riders often found themselves backwards on the verge in a corner.
And it was Saab that tamed the turbo
Because with a controlled Turbo incoming at low revs, you had the benefits of a much larger engine without the explosive power card of an untamed turbo. And the market asked for more power. The call for more powerful engines was answered by Saab with the introduction of the Turbo version, which really put the brand on the car map. The first Saab 99 Turbo was sold as a 1978 model. This particular Turbo was very successful in the Swedish Rally with Stig Blomquist at the wheel. Turbo engines were available in the Saab 1977 from 99 and a year later in the new Saab 900. Saab was not the first manufacturer to use turbo technology in passenger cars: Porsche, BMW and Chevrolet preceded the Swedes.
Not the first, but possibly the best
However, the Saab 99 was the first family model with turbo. A minor drawback is that compressed air tends to heat up and can therefore contain less oxygen. By placing an intercooler between the turbo and intake, the heating of the intake air is more than halved, which in turn leads to more efficient combustion, better cylinder filling, lower fuel consumption and better pulling power over the entire rev range.
The engine and turbo of a Low-pressure Turbo (LPT) and Full-pressure Turbo (FPT) are basically exactly the same, only the waste gate operation of the 900 LPT differs due to the lack of the APC and is immediately (as in the 900 turbo 8V from '82) activated by the inlet part of the turbo, without the intervention of electronics. The vacuum regulator of the waste gate has a spring with a different opening characteristic than that in the 900 turbo 16S. This leads to a lower power for the LPT (145 hp) than the FPT (175 - 190 hp).
The low-pressure turbo was a completely new application of the turbo principle
This offered an interesting alternative to the conventional injection engine. Torque has been improved by reducing the turbo's boost pressure capacity to reasonable proportions. The result is a smoother, more powerful engine with a lower noise level. Moreover
the low-pressure turbo system ensured that the emission of exhaust gases was reduced even further.
Currently, such a Saab turbo is a sought-after, highly deployable, heart-conquering classic
Because the last early turbos were made a while ago and the production numbers at Saab have never been enormous, the availability of a number of specific turbo components is no longer optimal. Fortunately, there are a few specialists who can provide a solution.
Turbo tinkering is not given to everyone
A turbo compressor. That simple. So effective