Official FMS 1400mm P-51D V8 Thread

[rckruser]

You'll be pleased!!
With my Bearcat, I used the same 650kv power system with the same 85A ESC and installed the 1400 mm FMS Corsair prop in front, incredible airplane, literally unlimited vertical.

Gman,
I went with the FL recommended 3648-880kv w/12x6 2-Blade (scale blasphemy I know I'll paint the wing tips yellow). Two reasons:
1. I read on another forum that the 14x8 prop is tough to fly from grass. I did some measurements. With the plane near horizontal there is only 1.375 inches from the prop tip to the ground. Our field is cut to .75" and gets to 1.3" between cuts. Just a little error on takeoff/landing and I'd be cutting grass i.e probable hard noseover.
2. $47 versus over $100.

Bernie

[Grossman56]

I hear you, for grass it's probably the better way to go. I just wanted that big scale fidelity prop so inherited the same problems as the full scale. I've never tried flying her off grass but I did install some Dave Browns that were slightly larger, but still retracted, the difference was amazing!
Still waiting for the 1600 mm FlightLine F8F, (HINT HINT!!)

Grossman56

[rckruser]

I hear you, for grass it's probably the better way to go. I just wanted that big scale fidelity prop so inherited the same problems as the full scale. I've never tried flying her off grass but I did install some Dave Browns that were slightly larger, but still retracted, the difference was amazing!
Still waiting for the 1600 mm FlightLine F8F, (HINT HINT!!)

Grossman56

Gman,
It looks like my Petie 2nd is a version 6. I've been reading on RCG where the wings are too flexible and the pilots have been performing a "one piece wing" mod and adding carbon fiber to the wings. Any experience with this? Still waiting on the new motor from FMS.

FYI the Bearcat went from 488W to 702 Watts with the new power system. Can't wait to try it.

Bernie

[Grossman56]

version 6, wow, that's a keeper in that its probably getting rare!
Mine is a V-8. I didn't glue the wings together but in hindsight it's probably a good idea although if you have to replace a servo, it may be easier if you can pull the wings apart, can't remember, it's been a while since I had mine apart. Mine has the stock wing setup and I have never had any problems (touch wood) with just the stock carbon fiber rod. After the first year, I replaced all the control surface servos (except the rudder) with metal gear servos and did the power upgrade to a 580, it was a bit better so I eventually went the 650kv when it came out with the P-40 and that was a great match. Since then, I've flown her for 5 years and never a lick of trouble doing sport aerobatics. I did lose my P-51B after the major rebuild, but she just didn't feel right and I suspect something in the wiring as she just wasn't happy in the air as she used to be. Still hoping for a Freewing P-51B with a Malcom hood, maybe in the colors of Major James Howard, CMH winner as well as ex Flying Tiger member

The airplane is the famous "Ding Hao!', shown here when she still had the stock canopy. I would love to see a line of airplanes depicted in the CMH recipients colors, it would be a cool tribute.

Grossman56

[Elbee]

version 6, wow, that's a keeper in that its probably getting rare!
Mine is a V-8. I didn't glue the wings together but in hindsight it's probably a good idea although if you have to replace a servo, it may be easier if you can pull the wings apart, can't remember, it's been a while since I had mine apart. Mine has the stock wing setup and I have never had any problems (touch wood) with just the stock carbon fiber rod. After the first year, I replaced all the control surface servos (except the rudder) with metal gear servos and did the power upgrade to a 580, it was a bit better so I eventually went the 650kv when it came out with the P-40 and that was a great match. Since then, I've flown her for 5 years and never a lick of trouble doing sport aerobatics. I did lose my P-51B after the major rebuild, but she just didn't feel right and I suspect something in the wiring as she just wasn't happy in the air as she used to be. Still hoping for a Freewing P-51B with a Malcom hood, maybe in the colors of Major James Howard, CMH winner as well as ex Flying Tiger member

The airplane is the famous "Ding Hao!', shown here when she still had the stock canopy. I would love to see a line of airplanes depicted in the CMH recipients colors, it would be a cool tribute.

Grossman56

GM, Kudos for photo. I bought the Jim Meister 'Master-Scale' Ding Ho kit back in the 80's. sadly, lost it during the marital readjustment of 2008-11. A campaign for a Flightline 1600 mm "B" model with a 'Malcolm Hood' option would be worthy, I would think. And yes, CMH Recipient Liveries would be quite cool. Loring's P-80, Davis's F-86, Day's Anything, there are more than 15 Air Force pilots and certainly many other pilots from other services. Great idea. Best, LB

[FLY BOY]

Hey Guys, I have made an interesting discovery. I recently upgraded my P51 motor to the KV650 from the P40, Only to find out I made the wrong choice. I'm now using the KV650 motor from the the T28 Trojan V4 instead. The why is the Trojan motor will handle 4-6s batt packs. I can run a 6s when I feel the need for speed on a stock 70amp ESC. Check out the T28 V4 specs. I dont know how I missed this before. I posted a video in the RC Comm FB page. The speed is incredible! Pocket radar clocked a top speed of 140mph, and with an average speed of 133mph. WOW!!!!! I am using though the 3 blade prop and and spinner from the P40 as it offers better cooling because the nose cone is vented, and keeps the prop thrust in the area spec of the T28. Plus it closes the gap a lot better between the spinner and fuse. Food for thought from the PNW

[xviper]

Hey Guys, I have made an interesting discovery. I recently upgraded my P51 motor to the KV650 from the P40, Only to find out I made the wrong choice. I'm now using the KV650 motor from the the T28 Trojan V4 instead. The why is the Trojan motor will handle 4-6s batt packs. I can run a 6s when I feel the need for speed on a stock 70amp ESC. Check out the T28 V4 specs. I dont know how I missed this before. I posted a video in the RC Comm FB page. The speed is incredible! Pocket radar clocked a top speed of 140mph, and with an average speed of 133mph. WOW!!!!! I am using though the 3 blade prop and and spinner from the P40 as it offers better cooling because the nose cone is vented, and keeps the prop thrust in the area spec of the T28. Plus it closes the gap a lot better between the spinner and fuse. Food for thought from the PNW

You should check the heat of the motor, ESC and battery connections after a 6 cell flight. I can't see anything on the FMS site for that motor that would suggest that it can be safely run on 6 cells. In fact, it states that 4 cell is the max with a max current of 60A. It's not even recommended for 5 cells. I know you "can" fly it on 6 cells but the question might be "for how many flights" before something burns up?

http://www.fmsmodel.com/fms-motor-4258-kv650-predator

[OV10]

I'm somewhat in the same boat of concern as you XV but didn't speak out initially because there are some glaring issues with regards to publicized info by FMS and Horizon.
The Predator motor that you link is the old P-40B one listed on the FMS site.
Horizon lists the gold case PAEP for the P-40B.

https://www.horizonhobby.com/4528-motor-kv650-fmmkv650

Both the motors have the same power specs of 4S.
The Horizon site lists a black case PAEP for the T-28 V4
https://www.horizonhobby.com/motor-4...00mm-fmmkv650n
Notice the N suffix on the part number.
While it is an upgrade to the 650 motor of being able to use 4-6S power, look for the sentence beginning with "The updated motor drives the power and speed about 30% higher" from the product Overview page of the T-28 V4.
http://www.fmsmodel.com/fms-1400mm-t...jan-yellow-pnp
The key statement is "In addition, it could work with 4S, 5S and 6S batteries to satisfy different customer requirements".
The actual spec page tab lists the 4S battery with a 70 amp ESC and a 13x9x3 blade
With all that being said and having been involved with numerous FMS mods and discovered and still possess the detailed FMS motor specs for all FMS motors before they were quietly taken down from the internet, I am skeptically questioning the same as you as to how long before the magic smoke is let out on that 6S battery powered motor.
I also think that the radar gun claims cause one to think that it needs to be calibrated because those speeds indicated are basically unachievable for this model powered as such.
And lastly, my P-40B running with the 4258-460kV motor from the P-47 razorback on 6S kept shredding the stock P-40 blades/hub whereas I had to go to a MAS 14x9x3 prop. Many have seen the unbelievable performance of that setup @ NEFI with unlimited vertical but it was nowhere capable of approaching 100mph plus.
I'm not from Missouri but I still need to be shown

[FLY BOY]

What caught my eye is the Horizon advertisement. It states that the the V4 Trojan will run on 4-6s batt packs, and it only has a 70 amp speed controller. The real advantage after the motor swap was the P51 is lighter, and has a better aero package. As I've always said, the proof is in the pudding. You can be a skeptic all you want, but it guys like me who play in the sand box that increase the fun factor for everybody. We did check the amp draw, and put the heat test gun to the motor and all are in very acceptable ranges. In fact by using the P40 nose cone the motor received better cooling and there was very little increase in heat between the 4s,and the 6s packs. You should check out the video I posted. You can see its definitely faster than 100mph. Happy landing from the PNW.

[xviper]

You should check out the video I posted.

Where's the video?

[FLY BOY]

The video is posted on the MRC FB Comm page. So I just got off the phone with Horizon Hobby. The gentlemen assured me that the V4 T28 motor is a 6s capable set up. Thats why FMS uses a harden steel shaft, and upgraded ball bearings as advertised. He also stated its all in the wire wrap. Just as the Turbo Timber can use 3s, or 4s batts. The V4 T28 works in the same manner. The next sunny day at the field, we are going to test the speed again with an on board GPS speed meter, and compare our results. Even if the results differ, its still a 100mph+ P51 foamy.

[JamesonC]

I just don't see how it is possible to achieve speeds anywhere close to that while only pulling less than 70a. I Run mine on 6s with the 550kv motor and have to run a 100a ESC. Even then, mine was clocked at only 93mph. Now, that is a big jump from the stock 67mph. BUT, I just don't believe this model is capable of speeds like 130-140mph. Just my $0.02 after having the plane on 4 different setups over the last 5 years.

[xviper]

The video is posted on the MRC FB Comm page.

Like searching for a needle in a hay stack.

[OV10]

I just don't see how it is possible to achieve speeds anywhere close to that while only pulling less than 70a. I Run mine on 6s with the 550kv motor and have to run a 100a ESC. Even then, mine was clocked at only 93mph. Now, that is a big jump from the stock 67mph. BUT, I just don't believe this model is capable of speeds like 130-140mph. Just my $0.02 after having the plane on 4 different setups over the last 5 years.

Absolutely.
Apparently he isn't aware nor understands the science behind speed relative to aerodynamics and the power coefficients required to overcome said forces of drag that affects higher speeds.
I stand with my last sentence of post #1274

[FLY BOY]

Well you guys have fun sitten on the bench. Im going to go fly my 6s foamy at 100mph plus all day long. I will let you know if the pocket radar is broken as we compare a GPS speed unit. For its not about understanding anything. Its about what the speed guns are saying. The reason were testing with a GPS speed unit now is the the pocket radar device that was used is now in question not only by the owner, but by 2 of our club members who have 100mph EDF's They all agree that my P51 is a cut above and its surly near the 100mph zone. But there not convinced its over a 100mph plane and also want to compare there EDF's in a side by side speed test. This is so exciting for me to say the least. Theres even going to be a Roc Hobby P51 Strega with a prop mod and has a documented top speed of 107mph. I have seemed to raise some eye brows for sure and I'm looking forward to getting down to business and finding out really just how fast it truly is. So with the current set up, How fast do you guys think it really is? The guys at the club are saying 90-95mph after reviewing the video. I will post the results this week end.

[JamesonC]

Well you guys have fun sitten on the bench. Im going to go fly my 6s foamy at 100mph plus all day long. I will let you know if the pocket radar is broken as we compare a GPS speed unit. For its not about understanding anything. Its about what the speed guns are saying. The reason were testing with a GPS speed unit now is the the pocket radar device that was used is now in question not only by the owner, but by 2 of our club members who have 100mph EDF's They all agree that my P51 is a cut above and its surly near the 100mph zone. But there not convinced its over a 100mph plane and also want to compare there EDF's in a side by side speed test. This is so exciting for me to say the least. Theres even going to be a Roc Hobby P51 Strega with a prop mod and has a documented top speed of 107mph. I have seemed to raise some eye brows for sure and I'm looking forward to getting down to business and finding out really just how fast it truly is. So with the current set up, How fast do you guys think it really is? The guys at the club are saying 90-95mph after reviewing the video. I will post the results this week end.

Have you put it on a watt meter yet? I really feel bad for that poor 70a ESC in there.

Your first post, you were saying 140mph, now we are talking a more realistic 100ish mph. Surely you can see why so many here were honest about it just not being possible to get 140mph out of that plane on that setup.

But, after watching the video and thinking on it, I would guess 95ish on an actual level pass without any "Horizon Hobby dives" to get whatever speed you want to claim.

[FLY BOY]

Again we were going by what the pocket radar was telling us at the time. Then we discovered after my bragging, which I apologize for that the radar device may be not calibrated for such speed. Because so many people through the red challenge flag, we started to dig deeper to make sure our claims were real. We discovered that the radar device we were using is spot on up to 65mph, Then starts to fade in accuracy after that. As much as 20mph when around actual speed of 85mph. I know that I was definitely fooled at first by the shear speed and whistling sound it made on the high speed pass. And yes the amps and watts are with in parameters on 6s. We knew it would work safely because its just the T28 factory set up but in a mustang which is lighter and has a better aero package. Will post the test results this week end.

[FLY BOY]

My peeps and I would also like to apologize .We never meant to mislead or make any false claims. We also elected to remove our video from the MRC Comm page until all the accurate data results are in. We love and respect the hobby and dont want to promote any unsafe, unrealistic, or misleading information that may lead to unsafe operations of any RC aircraft. Please except our apologies. Happy and safe flying from the PNW.

[Grossman56]

Hi Fly Boy, personally, it doesn't matter to me how fast you go, as long as you're having fun and if the speed you're getting gives you a rush, then good for you!!
Keep enjoying the hobby in the way that satisfies you, that's all that's important.

Grossman56

[FLY BOY]

Hi Fly Boy, personally, it doesn't matter to me how fast you go, as long as you're having fun and if the speed you're getting gives you a rush, then good for you!!
Keep enjoying the hobby in the way that satisfies you, that's all that's important.

Grossman56

And thats exactly what I'm doing G56, Thank you!!!