915iS Installation Questions

General purpose discussions.
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VictorValencia
Posts: 3
Joined: Tue Oct 12, 2021 6:49 pm
Location: Caldwell ID

915iS Installation Questions

Post by VictorValencia »

Hi,
Sorry to crash your forum but I'm a Kitfox builder and looking for someone that has installed a 915iS.
I'm trying to design the electrical system and there's some info I just can't seem to find anywhere.
<queue the Pink Floyd music>
Is there anybody out there?
<end music>

Victor
huzilulu
Posts: 30
Joined: Sat Dec 14, 2019 9:12 am
Location: Houston TX

Re: 915iS Installation Questions

Post by huzilulu »

Quite a few people have installed the 915… what’s your question - hopefully someone will be able to answer it…

Btw… we have a Sling-Kitfox builder on here as well… he will make himself known shortly :)
VictorValencia
Posts: 3
Joined: Tue Oct 12, 2021 6:49 pm
Location: Caldwell ID

Re: 915iS Installation Questions

Post by VictorValencia »

Here are the primary questions I am trying to find answers to:

1) The 915 has display CAN bus connections which provides engine sensor info to the G3x. What
sensor info is included on this interface?
2) What's the recommended method for measuring fuel pressure?
3) Does the G3x automatically resolve the redundant data coming from the 2 display CAN bus interfaces on the engine?

Victor
huzilulu
Posts: 30
Joined: Sat Dec 14, 2019 9:12 am
Location: Houston TX

Re: 915iS Installation Questions

Post by huzilulu »

Im not sure about the CAN bus data - my harness was built by Midwest Panels...

FP is measured using a T off the supply line to the rail... although Rotax just recently announced a new part to allow FP measurement off the rail end near the FP regulator (a new banjo bolt that will allow a sensor to attach directly to the rail)... you can look up SI-PAC-024 for Rotax
Cyrus
Posts: 22
Joined: Sun Dec 08, 2019 11:38 am
Location: KTIX, Cocoa, FL

Re: 915iS Installation Questions

Post by Cyrus »

Per the G3X installation manual, the data available is:

24.2.2.3 Rotax 912iS/915iS
The G3X system is capable of monitoring the following engine parameters from the Rotax 912iS/915iS
FADEC digital interface, when connected to the dedicated FADEC CAN interface on a GEA 24:
• RPM
• Manifold pressure
• Manifold air temperature
• Oil pressure
• Oil temperature
• Exhaust gas temperature
• Coolant temperature
• Fuel flow
• ECU bus voltage
• Throttle position
• Percent Power (Rotax 915iS only)
Fuel pressure for Rotax FADEC engines may be monitored using one of the two following methods:
• Use UMA 1EU70D differential sensor for fuel pressure.
• With a GDU 4XX system, select an appropriate fuel pressure sensor from Table 24-1 as
appropriate, and configure the sensor to display fuel pressure relative to manifold pressure (see
Section 35.4.32.11).
Refer to Section 24.2.10 for information about FADEC engine status display.

https://static.garmin.com/pumac/190-01115-01_ap.pdf

Additionally, there was a software update earlier this year that adds a bit more:
https://www.youtube.com/watch?v=3Ip3X8BlD-I
Cyrus
Sling TSi in progress.
VictorValencia
Posts: 3
Joined: Tue Oct 12, 2021 6:49 pm
Location: Caldwell ID

Re: 915iS Installation Questions

Post by VictorValencia »

Thanks Cyrus! Don't know why I did not see that. I think I was looking at an outdated installation manual.

Victor
JohnP
Posts: 2
Joined: Tue Jul 19, 2022 7:03 pm
Location: Bay Area Peanut Gallery

Re: 915iS Installation Questions

Post by JohnP »

The oil tank feeds the engine via a siphon tube at the bottom; if you invert gravity for too long, it will suck air - which for most engines is a Really Bad Thing...
Same for the fuel tanks - the fuel feed is at the bottom when flying right side up.
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