fresh air plenium

[fiveliters]

Tony-I am in the US,so I have the ZS carbs. Is it true there really aren't different needles for those (or if there are,they are so hard to find they may as well not exist)? Also,the hoses that were attached to the old style intake...where do they go now? There was one small rubber one that attached near the front of the box, another small rubber one that went to a disk inbetween the carbs on the box, and the long cardboard-ish tube that connects to the top of the exhaust manifold. I know the long tube is supposed to help the exhaust gases through the manifold or something to that effect,so should I keep it attached there,or remove it from the top of the manifold and cover/plug it some way? And the two small rubber lines, should they be plugged or just left free in the engine bay? Thanks!

[saabfast]

This sounds the same set up as the UK SU's. I think it is for a quick heatup system driven by engine vacuum. The vacuum line from the intake manifold goes to the 'disc' which (I think) is a temperature operated valve. When cold it allows the vacuum through to a damper in the end of box which closes the direct inlet and opens to allow hot air in from the hose which goes to the 'hood' over the inlet manifold to give a hot air intake. When things warm up the sensor closes off the vacuum to the damper which closes (spring return) to the hot intake and opens to the direct 'cold' intake, ie air from the front intake/engine compartment.
One problem I have had is the vacuum tubes perishing and allowing an intake leak, weakening the mixture. If the box is removed the vacuum line should be plugged at the manifold.

Alan
Saab 9000 Stg 1
'81 TR7 DHC

[jclay (RIP 2018)]

fiveliters,

You can richen the gas flow by raising the needles in the jet.




Have fun, drive fast & safe, be kewl,

jclay

[jclay (RIP 2018)]

Vacuum lines:




Have fun, drive fast & safe, be kewl,

jclay