Official Freewing 90mm F-15C Eagle Thread

[gooniac33]

I’ve been following these f15 tests and wanted to share my results with the fms 90mm 12 blade 1900kv fan upgrade. Aircraft weight with fms fan 2443g w/o battery.

Here are my numbers.

5200mah Zeee 50c pack
low timing 112amps 2236g thrust
mid timing 115amps 2300g thrust
high timing 126amps 2330g thrust

5000mah 70c chinahobbyline
low timing 125a 2450g thrust
mid timing 127a 2465g thrust
high timing 130a 2540g thrust

All amp results are peak amps and they usually drop off.

I don’t see how the manual says 4300g thrust.. Even fms says that the fan should push 3.26kg thrust @112 amps. Now I understand that it’s not getting any air pushed into intakes and my kitchen method is flawed. But really 4300g stock?

throttle calibration may not have been done... that sounds way less than what I have seen before. The plane may not be all that much faster but will fly better all around. Half throttle amp draw is way down from stock but it still moves much more air. When I switched out to this fan in the F-104 it helped in all ways. I gained 1 min flight time since less throttle was required to keep it in the air. Also its a momentum plane! Get it going and man it will really scream!

[RCjetdude]

Fan ratings much of the time are determined on a bench tester not in a duct which will reduce overall performance. Are you testing in an actual plane?

[Rcfiddy1]

This was tested in the plane. Not a true measurement since I only have acces to a kitchen scale and I only wanted to see what the fms put out. I’m going to try the original hp version fan. I’m just disappointed in the performance in this f15. She seems to drag it’s butt all day long, while my f14, l39, Avanti, 70mmf18, f16 move in a more authoritative way. If that makes sense.

[RCjetdude]

This was tested in the plane. Not a true measurement since I only have acces to a kitchen scale and I only wanted to see what the fms put out. I’m going to try the original hp version fan. I’m just disappointed in the performance in this f15. She seems to drag it’s butt all day long, while my f14, l39, Avanti, 70mmf18, f16 move in a more authoritative way. If that makes sense.

I know what you mean. I retired my Stinger 90 with JP 8S fan and Castle Talon ESC which in that plane was a sweet combination. Thought it would make an F-15 perform great but it did not live up to my expectations. It flies good but it is just a different airframe. Obviously more draggy and heavier. I think more of it has to do with wing loading too.

[gooniac33]

This was tested in the plane. Not a true measurement since I only have acces to a kitchen scale and I only wanted to see what the fms put out. I’m going to try the original hp version fan. I’m just disappointed in the performance in this f15. She seems to drag it’s butt all day long, while my f14, l39, Avanti, 70mmf18, f16 move in a more authoritative way. If that makes sense.

It is a draggy bird. It won't really be faster with the FMS set up but will be lighter and fly better all around.You can get it to move pretty good though if you get the right combo.If you want faster then you need to go another route. Either 8s or the higher performance 6s set ups that we have been using. Have you seen any of my videos? Here are some from last weekend... We have a ton of fun with it last weekend! Our goal with the set ups we used was to get much better than stock performance but using the same batteries that you would use stock. So I am using a 6s 55c 5000 China Hobby Line pack or Turnigy Heavy Duty 6s 60c 5000mah pack. There are some other packs I will be getting soon that are 6000s and 6500s. 3-6min flight times with our set ups with huge increase in performance as well... take a look...

Now this video is not the F-15 but my other friend uses the same set up that is in this F-4 in his F-15 and it made it a rocket ship. He ca get 5 min flights with throttle management but it still flies jet like at lower settings!!

[Flanker271]

This was tested in the plane. Not a true measurement since I only have acces to a kitchen scale and I only wanted to see what the fms put out. I’m going to try the original hp version fan. I’m just disappointed in the performance in this f15. She seems to drag it’s butt all day long, while my f14, l39, Avanti, 70mmf18, f16 move in a more authoritative way. If that makes sense.

A personal friend of mine was a Strike Eagle Weapons Systems Officer (sits on the back seat). He mentioned that aerodynamically, the F-15 airframe actually has the second worst energy retention in a turning fight out of all "teen-series" fighters. The reason the F-15 performs so well in combat is because of the two massively powerful F100 engines, which literally use brute force to achieve dominance in any AOA situations. We also talked about the MiG-25, which has similar aerodynamic configuration as the Eagle, and the maneuverability also sucks. It was quite an interesting conversation.

[RMatteson]

Just got a ARF Plus of the F-15 which I installed the new 9 blade FW fan from the F-4. I have watched the build and flight review, but they did not talk about elevator to flap mix. The F-16 needs up trim as nose pitches down with flaperons, and the F-4 needs up elevator as well. So what does the F-15 need when flaps are deployed ?? Thanks for input

[DCORSAIR]

I don't use any mix on mine, sure others do but mine is fine with full flaps, I even pop the speed brake out on final and add a little power for the extra drag, the F-15 is one of the best ones on landings. I'm curious how the 9 blade works in yours, I tried it and it wasn't much better than stock so I went with the 4068-1680kv and that works very well. Let me know how it goes.

[C17loadmaster]

I’m curious about the 9 blade too... I have a brand new one that I will put in one of my planes eventually. I bought the 8s version of the F-22 and the 6s unit if I prefer that

[DCORSAIR]

I like the sound of the 4068-1680kv is my problem, it has a nice woosh that sounds good to my ears for some reason, I like sound better than performance so that is why I went with the 4068-1680 in all my 90mm jets, didn't care for the whine of the 9 blade, but I gained both so I'm happy with the upgrade. Hope you like the 9 blade, it will fly the F-15, watch your timer because when I had the stock F-4 Phantom I was only able to get 2 1/2 minutes and that was it on a 5000 60C battery, don't know how others were getting 3 minutes, flight times were no better when I tried it in the F-15.

[RMatteson]

The reason I put it in was it has a lower amp draw then the inrunner, which I hope might be easier on my lipos. This is the same fan used in the new Raptor, which if you go by advertised weight is very close to the F-15 and also the F-4. I'm not sure why the Raptor was pushed as lighter then the F-4, but when I get mine we will see, where they all come in on weight. I have watched the video of both the F--22 and F-4 and for my flying style and comfort zone,, they fly plenty fast. I don't have a super large area to fly out of our bounds of our club field, as I see in some of the videos. Many of you guys are lucky to have such huge fly over areas where you can wring out these jets to the max. It is the beginning of the crap weather here in upstate NY, so I don't think I will get it out to try to spring.

[Lon]

I've got the 1835kv 90mm inrunner to try out in mine. Winter weather pretty much set in here. I'll do some static testing . Compare numbers to the stock setup. Won't be till after xmas though..

[DCORSAIR]

I've got the 1835kv 90mm inrunner to try out in mine. Winter weather pretty much set in here. I'll do some static testing . Compare numbers to the stock setup. Won't be till after xmas though..

Yes, please let us know how that power plant works out in the F-15, I'm happy with mine the way it is but want it for a couple of other 90mm jets that I might purchase, I can't find the 1680kv unit anymore, don't know if they are going to be replaced with the 1835kv or what but they seem to be out of stock.

[gooniac33]

I got a flight this past weekend with the Hobby Star 6s 50c 6200mah pack and man was it a blast! My plane is modded but usually gets 3 mins flat... no time to spare... I flew really hard and would have normally depleted my pack. Landed with 3.65v per cell... I may have a new fave F-15 pack....

[crxmanpat]

I've been flying mine with a RoaringTop 6S 6250 35C, and after 3 minutes of spirited flying I still have like 3.76 left in the pack.

[bill34207]

I use a pair of 4s 5000's and get around 3 and a half minutes, lands around 3.8 per cell.

[gooniac33]

I've been flying mine with a RoaringTop 6S 6250 35C, and after 3 minutes of spirited flying I still have like 3.76 left in the pack.

If I hadn't been flying like an idiot I am sure that it would have been about the same. However my current set up pulls around 145amps peak. Here are the videos of those 2 flights... the plane was very happy!!
.

[rifleman_btx]

That looks really nice!

[flyinhigh042]

It’s here! Thanks Motion RC. This thing is beautiful. Next up, order an Admiral Carbon 5100...

[Hardway]

It’s here! Thanks Motion RC. This thing is beautiful. Next up, order an Admiral Carbon 5100...

Welcome to Hobby Squawk!!! The F-15 is a nice bird!!! Happy New Year!! Jerry