Dave Anders Flying SDS EFI

[rv6ejguy]

Originally Posted by Chkaharyer99

This photo shows the Alt on the accessory case. No belt drive alternator detected. This option appeals to me for my consideration of the SDS system in that it removes the supposed vulnerability of the alternator belt from taking out the crank sensors.

Any downside to a system like this?

You need roughly 8-9 amps at idle to feed the EFI hardware plus whatever other loads you have. If you can do that with a a couple pad mounted alternators, it's viable.

Have not heard too much from Dave lately. He flying and doing some new mods for the Air Venture race I believe.

[F1Boss]

Originally Posted by rv6ejguy

You need roughly 8-9 amps at idle to feed the EFI hardware plus whatever other loads you have. If you can do that with a a couple pad mounted alternators, it's viable.

Have not heard too much from Dave lately. He flying and doing some new mods for the Air Venture race I believe.

Ross: Is this still the load if a mechanical pump is used?

Thanks!
Mark

[rv6ejguy]

Originally Posted by F1Boss

Ross: Is this still the load if a mechanical pump is used?

Thanks!
Mark

No. Using a mechanical pump would drop the current load 4.5- 5.5 amps depending on the Walbro pump used.

[rv7charlie]

Mark,

Are you asking about a stock engine driven pump? I don't know of any that will approach the 40+ PSI needed for automotive style injectors.

Ross,

Are you saying your system will work with the ~25 PSI from a Lycoming style engine mounted pump?

[rv6ejguy]

Originally Posted by rv7charlie

Mark,

Are you asking about a stock engine driven pump? I don't know of any that will approach the 40+ PSI needed for automotive style injectors.

Ross,

Are you saying your system will work with the ~25 PSI from a Lycoming style engine mounted pump?

People are flying with modified aircraft mechanical pumps using our EFI. Fuel pressure needs to be in the 40 psi range.

We'll be offering a smaller electric pump in late July for sub 150hp engines. This reduces pump current draw from around 4.5 amps (normal medium pump) to 3 amps. Mainly offered for Rotax 912 and Jabiru engines which have wimpy charging systems.

We also offer a larger pump for engines over 350hp which draws around 5.5 amps at 40 psi.

[rv7charlie]

Well, now I'm in Sgt. Shultz mode...

Can you share details on the mod to the Lyc style pump? Just increased return spring pressure? Which spring is used? Enough hours to tell whether there'll be problems with extra wear on the actuating cam & pump arm?

The automotive injection pump is the highest consumer of electrons, *and* drives the need for a mechanical bypass regulator, so if there's a way to do a diaphragm style pump driven by the engine, that simplifies both plumbing and electrical needs.

Charlie

[rv6ejguy]

Originally Posted by rv7charlie

Well, now I'm in Sgt. Shultz mode...

Can you share details on the mod to the Lyc style pump? Just increased return spring pressure? Which spring is used? Enough hours to tell whether there'll be problems with extra wear on the actuating cam & pump arm?

The automotive injection pump is the highest consumer of electrons, *and* drives the need for a mechanical bypass regulator, so if there's a way to do a diaphragm style pump driven by the engine, that simplifies both plumbing and electrical needs.

Charlie

I'm not sure of the mods done to the pumps, resultant life reduction etc. One is a Sport Class Continental which is a different design than the standard finger drive Lyc pump. I believe the Lyc users have fitted the Lear type rotary pumps.

Plumbing is not really simplified with the mech pump and you still need the bypass regulator to maintain proper differential over MAP for precise metering since pump output exceeds engine usage.

The twin electric pumps have proven to be 100% reliable to date if mounted and filtered as we recommend. The current draw is only a concern if you lose the alternator. We recommend either twin alternators (small vacuum pad one is fine for backup) and/or a backup battery with our EFI systems.

[Chkaharyer99]

Ross,

Do you have a preference for 2 alt and 1 battery or 1 alt and 2 batteries?

I can see that Dave has at least 1 alt mounted on his accessory case but there may be a second one back there I can't see I these pics.

Any idea how his electrical architecture is set up?

Is it 1 alt 2 batteries?

Thanks

[rv6ejguy]

I'm not sure what Dave is using for electrical backup but he has a mechanical fuel backup to make enough engine power to get the aircraft to a runway if the EFI was to fail. His LS EIs would only draw 2-3 amps at cruise rpm.

[Chkaharyer99]

That's a really cool feature Ross. I had no idea that option was available. I thought it was all electrical, no mechanical. That makes it more appealing. With
mechanical fuel pump only, what kind of performance could one expect from a lycoming IO360 with 9:1 pistons. Can you sustain flight? Or is it just prolong flight?

If you have documention on this feature, could you please send me the link where I can learn more?

Thanks