Considering the Rotax 915

Abid

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I Think Edge possibly.. use the Walbro GSL 393 , can depend on type of motor

normally aspirated or turbo and total boost psi...




GSL393-Flow-Chart.jpg

Hmm. I thought they used Bosch but may be Walbro is what they use. They are also good fuel pumps. Fuel pressure measurement on iS is to be done in differential manner against manifold pressure and that has to be 38 to 45 psi. Absolute fuel pressure measurement is useless. I made that mistake in the first installation.

Anyway, fuel pressure measurement is an optional measurement for Rotax. Because as soon as you have any drop in fuel pressure you will know in about one second as engine will start to shutdown. Looking at fuel pressure does not give you any more time. It’s just a good troubleshooting thing. Useless for safety as you will have the same result with or without it in a second or two.
 
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Burrengyro

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Lotus, Abid, Martin-av8r,
May thanks for the information. Gathering as much information and history as I can on the iS engines and the option of the Edge fuel injection retrofit for the future. John H
 

martin-av8r

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Hi Abid Thanks for the iS info

in the EFI world it is normally always differential fuel pressure , normally aspirated majority is 3 bar 43.5 psi

to set idle base fuel pressure with vacuum reference fuel pressure regulator disconected if you have one because idle intake vacuum lower differential fuel pressure under 3 bar , some is 4 bar 58 psi for better atomisation

with boost.. , with 1 to 1 reference fuel pressure regulator

with 43.5 psi base pressure , with 6.5 psi intake boost pressure you need 50 psi fuel pressure in the fuel injector input to see the same 43.5 differential fuel pressure at the output of the injector

some ecm have automatic closed loop fuel pressure compensation and safety with a fuel pressure sensor to compensate fuel pump pressure drop or variation with injector opening time to see the same lambda target or AFR - air fuel ratio , for protection and safety vs over rich or lean condition

for me fast calcul average - 1 psi = 2 in hg or 7 kpa

you said you see some data logs of the 915 iS , and it look like he have 4 egt

do you know or see in the logs what is the average egt delta or discrepancy between the 4 cylinder

at 4.5 to 5k cruise rpm , do you see if the ecm is capable of closed loop fuel trim per cylinder

with egt or just for safety to lower max temperature ?
 
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Abid

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Hi Abid Thanks for the iS info

in the EFI world it is normally always differential fuel pressure , normally aspirated majority is 3 bar 43.5 psi

to set idle base fuel pressure with vacuum reference fuel pressure regulator disconected if you have one because idle intake vacuum lower differential fuel pressure under 3 bar , some is 4 bar 58 psi for better atomisation

with boost.. , with 1 to 1 reference fuel pressure regulator

with 43.5 psi base pressure , with 6.5 psi intake boost pressure you need 50 psi fuel pressure in the fuel injector input to see the same 43.5 differential fuel pressure at the output of the injector

some ecm have automatic closed loop fuel pressure compensation and safety with a fuel pressure sensor to compensate fuel pump pressure drop or variation with injector opening time to see the same lambda target or AFR - air fuel ratio , for protection and safety vs over rich or lean condition

for me fast calcul average - 1 psi = 2 in hg or 7 kpa

you said you see some data logs of the 915 iS , and it look like he have 4 egt

do you know or see in the logs what is the average egt delta or discrepancy between the 4 cylinder

at 4.5 to 5k cruise rpm , do you see if the ecm is capable of closed loop fuel trim per cylinder

with egt or just for safety to lower max temperature ?

I was not looking for EGT. I was concentrating at fault logs to solve problems but I should next time. I am not exactly a motorhead but I understand enough what you are saying. I will check the data for lambda next time.
 

loftus

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When setting up the Edge ECU after the first start-up, the first adjustment beyond baseline settings was the TPS (throttle position sensor) from 0 at idle to 100 at full throttle, then adjustment of AFR (lambda) at increments of 500 RPM through the range from idle to full throttle. I was assisted in this by Michael Busenitz the Edge agent in the US, remotely on Zoom. Once this was completed the O2 sensor could be removed to allow for use of 100LL if needed, though I run Swift Fuel as much as possible. EGT temps were checked for being in an acceptable range, but otherwise no direct influence on the ECU settings. Fairly simple setup once I understood it.
For those possibly interested in the Edge conversion, my overall impression was that it is an extremely high quality, beautifully made kit. The kit was complete with everything needed except of course fuel plumbing lines beyond the engine itself which will vary from aircraft to aircraft. Instructions were clear and response from both Michael Busenitz and Thomas Haulklein of Edge in Norway to questions and need for some small parts that I messed up were excellent. As you can see from the photo, esthetically it's a very nice product and in my case the colors match. :) The photo was taken on completion of the engine component and before I tidied up the wiring, and completed the plumbing back to the fuel tanks etc.untitled shoot-001.jpg
 
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GyrOZprey

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WOW ...loftus ..I had no idea you did the EP upgrade! Michael is working on my red gyro ...right now ! I ordered the EP 914 kit in April ...after yet another float recall fiasco & recurring issues with my airbox sensors that messed up the turbo kick-in! It took all year to get the kit shipped ...due to the Norway HQ move to bigger premises (too successful!!!) and getting way behind on production & shipping ...maybe some supply chain elements also!????


I'm delighted to have Michael as my Rotax mechanic & only4 miles away from my place!
 

loftus

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WOW ...loftus ..I had no idea you did the EP upgrade! Michael is working on my red gyro ...right now ! I ordered the EP 914 kit in April ...after yet another float recall fiasco & recurring issues with my airbox sensors that messed up the turbo kick-in! It took all year to get the kit shipped ...due to the Norway HQ move to bigger premises (too successful!!!) and getting way behind on production & shipping ...maybe some supply chain elements also!????


I'm delighted to have Michael as my Rotax mechanic & only4 miles away from my place!
Yes, great that you have him nearby. Tell him I said hi, he'll probably comment on all the stupid questions I asked. :ROFLMAO:
 

wolfy

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Loftus, Mine is the carb mate electronic.
My current engine was a 914 that has had the electronic controlled turbo removed and a normal pneumatic actuated turbo installed in its place, so there are no electrics other than what's on a 912.

wolfy
 

Abid

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WOW ...loftus ..I had no idea you did the EP upgrade! Michael is working on my red gyro ...right now ! I ordered the EP 914 kit in April ...after yet another float recall fiasco & recurring issues with my airbox sensors that messed up the turbo kick-in! It took all year to get the kit shipped ...due to the Norway HQ move to bigger premises (too successful!!!) and getting way behind on production & shipping ...maybe some supply chain elements also!????


I'm delighted to have Michael as my Rotax mechanic & only4 miles away from my place!

Just 2 days ago Edge Performance posted on Facebook that they have 34 engines to do and should be very busy in 2022. From my personal inquiries, they are stating that if I wanted an Edge Performance converted engine (based on 912ULS), it would be 9 months to a year before I will see it. That pretty much stops everything in the tracks even if I wanted to offer EP as a standard option. Their Canadian dealer said partly its because of Rotax supplying the 912ULS and how long they take. I cannot say I can stand for that because I ordered 912 and 914 recently and within 2 weeks I got the engines here. I think its more EP's own delay.
 

Burrengyro

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Loftus, Mine is the carb mate electronic.
My current engine was a 914 that has had the electronic controlled turbo removed and a normal pneumatic actuated turbo installed in its place, so there are no electrics other than what's on a 912.

wolfy
Hi Wolfy, Did you just remove the electronics only? You did not replace the turbo unit, just a new installation using pneumatic actuated waste gate lever? Please post how you set up the pneumatic actuated turbo? If I recall correctly, you mentioned that you get more HP from this new setup?
Best regards, John H
 

wolfy

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Hi Wolfy, Did you just remove the electronics only? You did not replace the turbo unit, just a new installation using pneumatic actuated waste gate lever? Please post how you set up the pneumatic actuated turbo? If I recall correctly, you mentioned that you get more HP from this new setup?
Best regards, John H
Yes all the turbo related electrics are gone.
The turbo was replaced with a turbo from EP, it wasn't installed for more power but rather just to remove the electrics.
However with the larger jets ect talking to a local expert it is probably producing 120hp, naturally there are more horses there if wanted but that is not my goal. I'll try to get some pictures next time I'm looking at it.

wolfy
 
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