correct fuel for 914 turbo ?

[weedy]

Swannie, these are very valid questions! Well done for picking it up. Most of us actually have no idea.
Kalahari, Dobbs and OzGyro are quite correct.

In simple terms (and I am simple so I will try to explain it best I can)...

Your 914 turbo runs all the time. Fact. Check it out for yourself, if you have a Manifold Air Pressure gauge you will find that before you start the engine, it sits at about 29 inches of mercury (29.92 to be exact). I am talking about at the coast - depends on density altitude - but that is another lengthy discussion. Now start the engine and open the throttle to 100% power (to the stop in a Magni) 100% power is 35 inches of mercury. That means (at the coast) that the turbo is actually pushing 5inHG more than standard atmosphere and you can run at that power all day - 29 inches in the cruise is better because then the turbo is simply idling along. If you 'engage the turbo' it (should) go to 40 inHG (no more - beware) This is in effect 115% power (max 5 minutes) because any longer then your turbo will overheat and seals/gaskets will go etc.

Rotax specifies that you should use a different oil (fully synthetic/semi synthetic) if you are going to run on AVGAS (100LL) for extended periods rather than on the 'unleaded' you usually use. I am told the reason for this is that the lead deposits in AVGAS will be absorbed by the oil. I can't remember which oil for which fuel and don't feel like looking it up late on a Friday night. Ask your AP and if he is worth his salt, he will know. If he doesn't know... find another AP. Mine does.

Look after your engine and it will look after you. Give it the right fuel/oil. Also, more knowledgeable people than I have taught me that it is crucial to warm up and cool down your engine adequately and correctly or it will let you down. Take your time about this.

Fly safe

Len

Yip up in gansters its normally 25 inch and I also cruise on 29 inch so am getting 4"

Seems a lot of gyro pilots are under the impression that the turbo only engages past the detent, but not so.

In a normally aspirated engine it is impossible to have a manifold pressure higher than ambient, so a normal 912 will not pick up a two seat gyro up on the highveld.