Official FMS 1400mm P-51D V8 Thread

[Evan D]

The S means series. A 6S battery is 6 cells in series. P means parallel though it's rarely uses anymore in RC. C means capacity, as noted, and is normally used for a discharge rating. a 30C battery can be discharged at 30 times is capacity. A 4000mAh 30 C can be discharged at 30 times 4000mA or 30 times 4 Amps or 120 Amps. It is also used as a charge rating as noted and the same math applies.

[curlyculp]

Hello Curly,
The power mods to this bird have been well documented over the years as well as the recent past because of the latest motors to hit the market.
So to put things in a nut shell for you versus perusing hundreds of pages on both the forums looking for those pearls, here ya go.;)


Hope this helps,

SO, I got the stuff recommended, KV650 motor, 85A ESC. I put it all together, put the prop on and bench ran it on a 3200ma 30C 4S battery. In only 3 minutes at medium to high power it drew the battery down to 22%. The back of the motor was pretty darned hot but I've never felt one before after running so maybe this is no thang.

Now, I know bench running it with the prop on puts a bigger load on everything than actual flying loads as the prop is always pulling stationary air. I know I'll get a little longer performance airborne...

but, if I get a 5000ma 4S battery will it do better? I would think so.

Other than max and min power which is programmed easily, is there anything else I'm supposed to program on the ESC?

[xviper]

SO, I got the stuff recommended, KV650 motor, 85A ESC. I put it all together, put the prop on and bench ran it on a 3200ma 30C 4S battery. In only 3 minutes at medium to high power it drew the battery down to 22%. The back of the motor was pretty darned hot but I've never felt one before after running so maybe this is no thang.

Now, I know bench running it with the prop on puts a bigger load on everything than actual flying loads as the prop is always pulling stationary air. I know I'll get a little longer performance airborne...

but, if I get a 5000ma 4S battery will it do better? I would think so.

Other than max and min power which is programmed easily, is there anything else I'm supposed to program on the ESC?

A 3200mah, 4s is not much of a battery for this plane, especially when hopped up like that. I flew mine on 4000mah, 4s and then 4000mah, 6s when upgraded again. These give a decent 5 to 7 minutes. You'll also find that with the more powerful system, you won't fly it "medium to high" power most of the flight. The more power the thing has, the less likely you will fly it "balls to the wall" much of the time.

[curlyculp]

A 3200mah, 4s is not much of a battery for this plane, especially when hopped up like that. I flew mine on 4000mah, 4s and then 4000mah, 6s when upgraded again. These give a decent 5 to 7 minutes. You'll also find that with the more powerful system, you won't fly it "medium to high" power most of the flight. The more power the thing has, the less likely you will fly it "balls to the wall" much of the time.

I mounted the KV650. (yes with the P40 motor mount the holes line up.) And static ran it. I use a rope harness and hook an electronic fishing scale to it to measure static thrust. The original motor was registering mid 7 pounds of pull. The 650 is measuring mid 8's. With the same 4S 30C battery as the original. I'm looking forward to seeing how it works with the 4s, 5000ma 60C I ordered.

[xviper]

I wasn't talking about thrust. I was talking about flight times because the 650 draws more juice to produce that higher performance.

[curlyculp]

I wasn't talking about thrust. I was talking about flight times because the 650 draws more juice to produce that higher performance.

It's all related. If it puts out more, you can run around at a lower power setting. As you pointed out before. I was running my T-45 70mm EDF with a 4000ma 6S and only getting 4 minutes or so out of it. I put my 5000ma in it and ran the same profile and came back with over 50% battery.

[xviper]

I don't know about anybody else, but when I mod up a plane, I don't continue to run around at a lower power setting. :Silly:

[curlyculp]

A 3200mah, 4s is not much of a battery for this plane, especially when hopped up like that. I flew mine on 4000mah, 4s and then 4000mah, 6s when upgraded again. These give a decent 5 to 7 minutes. You'll also find that with the more powerful system, you won't fly it "medium to high" power most of the flight. The more power the thing has, the less likely you will fly it "balls to the wall" much of the time.

Finally got the Mustang out with the 650 and 85A ESC. Ran both a 4000 and 5000ms 4S. Ran GREAT!! Very noticeable performance improvement. A whole new airplane.

[Grossman56]

[QUOTE

Finally got the Mustang out with the 650 and 85A ESC. Ran both a 4000 and 5000ms 4S. Ran GREAT!! Very noticeable performance improvement. A whole new airplane.[/QUOTE]

That's what I ended up doing as well, tried the 580, but it wasn't very noticeable. The 650 gives it a much more scale-like performance. Fortunately, after seeing CB's P-40, I swapped out the motor in that for the 6s system from the 1500 FMS P-47 and had a spare 650kv. The only Mustang that's running a 580 right now is My Little Gal II (Resurrected) which is a FW P-51. My Old Crow is running a 650kv and it works great in it as well as the FMS P-51s.


Grossman56

[JamesonC]

I somehow missed there was a thread on this plane over here on Squawk. I have a V8 that has had all 4 of the main motor options on it along the way. It is now on the 550kv 6s setup and I love it! For general info, here are the radar speeds off each setup I had. All were with no prop mods or shims:

Stock 540kv - 67mph
580kv - 73mph
650kv - 78mph
550kv (6s) - 93mph

[prestonowtm]

Man...I just cracked up my old Redtail. Wind was too high but I flew anyway since it had been weeks since I have had anything in the air. New fuse and a few parts on the way. Probably had more than 150 flights on it. Dropped it in twice doing touch and go's to make sure I could get it down safe. The third time in a crosswind blew it 45% to port and right into one of my shop doors...crap. It was like someone just slapped the nose right to the side...tink, boom.

[Drake]

I am planning on doing the prop mod, I ordered the screws from the link listed at the start of the thread, for others it is worth mentioning that each order of screws comes in a 12 pcs to a pack...I thought they were sold individually, so I ordered 8 for spares, ha-ha, I got plenty of spares now.

[Boots Whirlygig]

I have the FreeWing Old Crow which comes with the 580, but it’s a 4258 size, not the fms “upgrade” which is the smaller 4250 size.
Also the prop adapter is the same as used by fms, and the same screw pattern, unlike the prop adapter used by Flightline.
I would recommend using the Old Crow motor as an upgrade to the FMS P-51,and you will want to get the fms F3A prop adapter if the gap bothers you! It bothered me!

[jadams812]

Hello Curly,
The power mods to this bird have been well documented over the years as well as the recent past because of the latest motors to hit the market.
So to put things in a nut shell for you versus perusing hundreds of pages on both the forums looking for those pearls, here ya go.;)
What I am presenting below is a basic bolt in swap of equipment that doesn't require any frame modifications and can still use the 4 bladed prop.
First the motor mount X brace hole spacing is 30mm at the plastic motor mount.
There are two newer FMS motors that have the same X mount brace spacing as the 4250-540kV stock motor & the 4250-580kV which was the early years upgrade along with the zip tie prop mod and bigger ESC.
For a 4S setup you will use the 4258-650kV from the FMS 1400 P-40B.
For a 6S setup you will use the 4258-460kV from the FMS 1500 P-47.
For either one of these motors you will need to use this prop shaft adapter from the FMS F3A Olympus in order to keep the spacing for the spinner appropriate because both of those motors are 8mm longer than the stock 540.
You will also need to upgrade the ESC from the stock 70A to a minimum of 85A. I used the ZTW 85A with no issue on both my 1400 Stang and Corsair upgrades.

Now the Motion product page for both versions(Redtail & Petie) they show an optional upgrade to the 580kV that I mentioned earlier.
The documentation is somewhat misleading.
" FMS 4250-580kV motor which will pull 62A (static) and yield a significant boost in performance. The 580Kv motor is 2mm longer so there will be a slight gap between spinner and cowl"
First it does not provide a "significant" boost in performance and secondly the 580 is not longer than the 540.
Also the 62A static draw is over the 56A max rating of the motor. This is why the 580 was not a long lived upgrade.
They also recommend the 100A Castle ESC which is an overkill for power demand needs and $40 more than the ZTW.
I did those 580 upgrades back in the day and they were so-so, when the 650 and 460 came out now that was the boost.;)

Hope this helps,

Thank God I ran into this thread today. I had just placed an order for the 580kV upgrade and so, now, have requested order cancellation in favor of the 650kV or 460kV mod. Also, I was a bit curious about the whole "2mm longer than stock 540kV motor" statement, as I was already measuring a 2mm gap on the stock set up. You cleared that up nicely. Thanks, OV, for the encapsulation. It is greatly appreciated!

One question concerning the ESC you recommended; are you using the factory default settings?

Thanks again!

[Grossman56]

Regarding the Gap from the spinner to the fuse, here's the before and after on Old Crow...



Makes a big difference if your looking for the scale look.

Grossman56

[OV10]

Thank God I ran into this thread today. I had just placed an order for the 580kV upgrade and so, now, have requested order cancellation in favor of the 650kV or 460kV mod. Also, I was a bit curious about the whole "2mm longer than stock 540kV motor" statement, as I was already measuring a 2mm gap on the stock set up. You cleared that up nicely. Thanks, OV, for the encapsulation. It is greatly appreciated!

One question concerning the ESC you recommended; are you using the factory default settings?

Thanks again!

Stock factory settings on most ESC's are sufficient;)

[jadams812]

Thank you, OV and Grossman. It's refreshing to find so many helpful voices. Quite a rarity these days.

[prestonowtm]

Regarding the Gap from the spinner to the fuse, here's the before and after on Old Crow...



Makes a big difference if your looking for the scale look.

Grossman56

Hey Grossman...figured out why the FMS canopy wouldn't go on to that new fuse. Feel dumber than a rock. The freakin magnet on the new fuse was backwards. Of course after I trimmed the crap out of the foam, then colored it trying to find where it was catching per your advice...all to no avail...lmao backwards magnet.

[Grossman56]

I had that with the battery hatch on My Little Gal, the magnets on Old Crow were such that her battery hatch cover repelled off My Little Gal, fortunately, when I got the replacement for MLG, the magnets were correct. The assembly line must have reversed the magnets on Old Crow for some reason, but they wouldn't have known because it worked for her. Weird.:Silly:

Grossman56

[Boots Whirlygig]

Any of these 4258 motors are the perfect upgrade, a virtual drop in with the F3A prop adapter and the higher cap ESC.
The Freewing 4258-580kv and it’s propellor and spinner will fit your FMS Mustang, and the propellor has a broader blade to move more air than the fms prop. See the photo.
I know the 650kv is swapped into the warbirds that have 3 bladed propellors and me thinks the FreeWing 4258-580kv is better matched to the Stang’s 4 blade prop on 4S.
My Old Crow is now sporting the P-47’s 460kv motor, which we already know can spin a 14x8 4blade with authority!