FMS 1700mm Mustang low power

[Rick227]

Well I thought I would post again after doing the prop mod and changing batteries...I switched to a 3700 70c Roaring Top and also a 3300 45c Roaring Top...and the combination of these two things have really changed this AC .. I really liked this airplane before but now it’s an awesome plane...performance improved dramatically ..what a difference...thanx

[PaulZ]

So I just bought this plane - always wanted a big mustang. I maidened it this weekend, wow what a great flying model! Yes, it will not break any speed records but she handles so well, no bad habits at all.
After about 8 flights and great landings I noticed that one of the retracts was not opening 100% of the way.

I am thinking of using the new xwave retracts from MRC - anyone tried these yet?

[Alpha]

Hi PaulZ , congrats on your successful maiden! We've sold many of the Xwave retracts since last year but I haven't seen anyone who has installed this in an FMS 1.7m Mustang yet. I can't imagine it would be a difficult mod to do.

That big Mustang is still a slick looker and nice flyer despite its years. I liked it better than their big Corsair. Odd battery arrangement aside, I actually enjoyed their big P-47 the most.

[Hugh Wiedman]

So I just bought this plane - always wanted a big mustang. I maidened it this weekend, wow what a great flying model! Yes, it will not break any speed records but she handles so well, no bad habits at all.
After about 8 flights and great landings I noticed that one of the retracts was not opening 100% of the way.

I am thinking of using the new xwave retracts from MRC - anyone tried these yet?

PaulZ, Job well done on the maiden. I've had this P-51 for maybe 2 years now and agree completely with Alpha, it's a looker, great presence in the air and infinitely better than their big Corsair (which is almost 1.5 pounds heavier). Still at about 8 3/4 pounds, this P-51 is no feather. I found that a lighter battery, such as the 4000mah, allows it to be a little quicker and climb better than the recommended 5000mah battery, while still giving about 5 minutes flight time as you can use less throttle to do the same flight routine. Even so, the 5000 gives a few more seconds (30) of flight time but I find myself using about 10% more throttle to do the same maneuvers. Some have done a prop mod, but I left it stock and like the big 4 blade. It flies very scale, in my opinion, and is always with me on prop warbirds days. It takes off and lands beautifully. I also put the sound system in it and the Merlin engine sound is extremely loud, given the large fuselage area to resonate the sound with.

For the first 20 flights, I had major "issues" with both retracts. My issues where that the retracts would not fully retract while flying unless I inverted and dove down while retracting the gear. I had put the 3 3/4" Robarts on which were heavier than the stock wheels and the stock retracts didn't have enough guts. I then purchased their full metal retracts and ever since I have never had a problem with the gear. So it doesn't surprise me whenever anyone has problems with their stock retracts-they just don't have enough punch. So my only advice is, replace them with whatever you can make fit and that should be the end of your troubles.

Below is the WW2 warbirds day for me from a couple weeks ago, and I don't know how the F4 snuck into my truck that day but she was whining about not getting enough action and I had to bring her along to shut her up (yes, I know, I need therapy because lately all my planes talk to me and whine like children if they don't get to go along every time-don't yours talk to you too?)

[OV10]

(yes, I know, I need therapy because lately all my planes talk to me and whine like children if they don't get to go along every time-don't yours talk to you too?)

Hugh...….. I used to claim the same about my birds but not anymore since the inferno cause I now have to listen to the haunts of the their ghosts

[PaulZ]

Hi PaulZ , congrats on your successful maiden! We've sold many of the Xwave retracts since last year but I haven't seen anyone who has installed this in an FMS 1.7m Mustang yet. I can't imagine it would be a difficult mod to do.

That big Mustang is still a slick looker and nice flyer despite its years. I liked it better than their big Corsair. Odd battery arrangement aside, I actually enjoyed their big P-47 the most.

Thanks Alpha! The FMS retracts are real junk, I ordered the xwaves already. Let's see how they fit. Based on the dimensions on the web site they should fit well. I may have to replace the FMS gear sequencer too since the FMS retracts deploy on -100 signal and Freewing and others on +100. I guess FMS has to be different...

[PaulZ]

Thanks Hugh Wiedman for the pics and update. I used a 6s 5000 in my P-51 and had to mod the battery tray to fit it in there. It CG'd perfectly with the 5000 all the way back as far as it would go to still close the canopy down. It's a great plane and flies very scale with the 360kv motor.

[Davy101]

I found with mine (360kv, no shims, 6s 4000mah 40c) flying with the rear radiator vent open made a lot of difference. It sounds silly, but without that open, there isn't a large enough air exit, so it dams up in the fuselage causing extra drag. Open it up and it will fly much more slippery.

[PaulZ]

I attached the vent servo to the throttle channel. That way it opens when you throttle up, just like the full scale plane. Not sure why the vent was wired to the flaps?

[Hugh Wiedman]

I attached the vent servo to the throttle channel. That way it opens when you throttle up, just like the full scale plane. Not sure why the vent was wired to the flaps?

I think the theory was that when using flaps, you are theoretically traveling at a slower speed, and therefore need it open further for cooling. I still have mine wired to the flaps, however, it's 1/2 open with flaps up and then opens 3/4 to full when using flaps. And I agree with Davy101, it does fly better with it at least 1/2 open, and never closes.

[PaulZ]

After some Dremmel work the XWave retracts fit perfect. They have more power than the stock FMS and can pull the heavy wheels up as needed. This is a needed upgrade for this bird.

[Hugh Wiedman]

After some Dremmel work the XWave retracts fit perfect. They have more power than the stock FMS and can pull the heavy wheels up as needed. This is a needed upgrade for this bird.

Nice upgrade, you're ahead of the pack as usual. Still have my FMS retracts in mine, but the so called "upgraded retracts" made out of metal. They've worked OK for the last couple of years, so no complaints yet, but if they ever miss a beat I'm following your lead.

[PaulZ]

Nice upgrade, you're ahead of the pack as usual. Still have my FMS retracts in mine, but the so called "upgraded retracts" made out of metal. They've worked OK for the last couple of years, so no complaints yet, but if they ever miss a beat I'm following your lead.

I would have also used the metal FMS retracts as they are a drop-in replacement but they are no longer available. Not sure why?

[Hugh Wiedman]

I would have also used the metal FMS retracts as they are a drop-in replacement but they are no longer available. Not sure why?

Because I bought all of them for my parts inventory a while ago, just in case, don't you know. If I'm not mistaken, my inventory list shows 6 metal retracts on it. If you might need one or more, just let me know.