FLM BL Savage woes..PLEASE HELP
 

Hey all, new here and need some help. Here are the specs so you can ponder as you read.

ALL FLM savage
Diff's-- stock
Tires-- Big Joe
ESC-- MMM
Motor--- Feigao 9xl
Spurr--48t
Pinion--10t
Batt-- Apache 4s 3700mah 20c lipo
tranny---3 speed

Here is the story....Truck origionaly had 16 pinion and 6 cell lipo and smoked the MMM on first run(was stupid fast though). Bought a new MMM and changed the pinion to a 10 tooth and set my radio for a 90%max throtle. All the MMM settings are stock except the reverse is shut off and the auto-lipo setting is on. After about a good 10 min of checking the temps every 30 seconds the motor got to 200F and the battery was about 135F. I stopped running it after that. It seems like there are several people here with about the same setup running the 16t pinion and not having any problems. I keep thinking the the cheep battery is the problem. What do you guys think???????
thanks, eric

It could be the batt, what c is it? mah? Brand?

Apache 14.4v 4s 3700mah 20c

Thats a fairly small battery for a big rig like that. I would look at something with a higher current capability. Technically it doesnt even meet the minimum spec for the MMM. They say that it should have 75A continuous rating. Thats only 74. I know... Its only one amp, but the point is the battery is very minimal and that FLM savy is shurly a heavy rig.... especially with those heavy big Joe tires to turn.

Would that be a higher amp hour or a higher C rating.....like the tantic packs

Both - something like a 6000 25c pack would get you 150amps...

I think the first thing you need to do is gear down more. 40 series are heavy compared to the stock tires and most people are running the 52t spur in their flm setups. Try the 52t spur and see how you go. Also when is it shifting? Setting the shift points later should help drop the amps a bit too.

I will see if I can find a 52t in metal. I think Robinson has one. It also looks like I need to get some smaller tires. I love the 40 series though, I just picked up a set of wheels from a cen cst7.7. They are slightly taller but half as wide. Should those be for show and the stock savage wheels for playing?

this is off topic .can u pls post ur sav pix ..i want to see how u placed ur batt tray .also what kind of batt tray do u use?

I am working on changing that right now. I will have pics when finished.

HPI make a metal 52t spur...

The Big cen tires will need some low gearing. I plan on using them on my flm savy.

And get a better battery, 5000mah 25c 4s at the minimum...

I switched from the RRP 48t spur to the HPI 52t metal spur from the XL and it's been holding up fine. The downside to the HPI spur is that it's thinner and only uses 1 slipper pad.

When I was running a Feigao 8XL geared 48/16 my motor temps were in the 180-190 range, but I was running stock size tires. Regardless of your gearing, you may be asking too much from the 9XL. Big wheels and tires and a 14lb truck are going to raise your motor temps. Put the stock tires and the 16t pinion back on and you should be good....

As long as you get a better battery. :)

Hi,

I don't know about your tires but I think 4S is too low a cell count. The current draw will be a little high. I recommend 5S 5000mah 20C lipo. I'm running a similar setup with truggy tires with 15/49 gearing. Only problem so far is the esc too hot (BK9920). I'll be switching over to MMM soon though.

Regards,
Joe Ling

PS : forgot to mention that mine is only a 2 speed tranny

5s is only going to raise the amps unless you gear down considerably to compensate.

I think 5S is just nice. With the setup of 5S & 9XL, you're looking at less than 35K rpm, a nice range for the motor. Gearing if looking at 2 speed is for a setup of 15/49 (pinion/spur) is 23.94 to 1 for 1st speed & 16.61 to 1 for second speed. Not sure what the 3 speed is though but it's surely not as high as the 12.2 to 1 (13/48 pinion/spur) that a buggy typically sees.

If u are using 10/48, gear ratio will be 35.9 to 1 & 24.91 to 1 for a 2 speed tranny (sorry, don't have the gearing calc. for a 3 speed). I think the motor is working too hard & it's under geared. Why don't u try a pinion with a higher tooth count like 13T or 14T ?

Regards,
Joe Ling

Thanks joeling, that is some of the best info I have had so far. I think I am going to go with a really good 5s batt and an eagletree datalogger so that i will know rpm,amps and temp for whatever setup I have.