Will there be cooling issues
 

I was just going over my buildup of my next project and i was going through possable problems that could happen and i was wondering if heating of the motor would be one of them. I will be running slipperential, 7xl, quark with one 2 fans, rc monster heatsink for esc, external ubec, 4s lipo a 20t pinion, standard size dish 17mm wheels and crimefighter tires and a 36t spur. Do you think i will have heating issues. if so what can i do to fix this. Also if there should not be heating problems is there anything i can do to help the motor run cooler just to be safe. Also the rc monster heatsink for the motor does this fit the 7xl and will this help with the cooling issues. (if this helps my truck will be using a combonation of graphite, titanium, and a small anount of aluminum like the combo bulks and alu diff cups and thats all that will be aluminum so i think the truck will be slightly lighter than stock but not sure.) Thanks a lot :)

20 tooth pinion with 36 tooth spur. You are geared right hi.

i think? so but what about heat issues

With gearing like that. It will put alot of amp draw on batts and esc.
It will make things heat up pretty good. Why such a hi gearing?
Do you have it locked in first gear?

Maybe this helps...:005:

I did a little figuring and with the 7XL, 4S LiPo (3.7v per cell), buggy diffs, and the slipperential geared 20/36, I came out with about 40 mph. That is about right....Isn't the reason your not going with the buggy diffs the fact that you couldn't gear it high enough? Well, I think you can....Not sure, but I'm pretty sure that 20/36 is possible with the slipperential. It should allow enough adjustment...Even then, I think you could manage to get Mike to get you a 22T pinion. I know for a fact that he can get a 24T but you shouldn't need a pinion that big. Anwho, 16/36 should be about right if you don't go with the buggy diffs...

the reason for the high gearing is because i want to achieve 50ish buy being able to use the slipperntial, 4s lipo, and a 7XL. i was going to run HB diffs but i swiched to maximizer because of the lower ratio (2.8 v.s 3.something for HB diffs) for this lower ratio allows me to achieve my disired speeds without changing from 4s to 5s. Also i wanted to gear it so high (if high means up on pinion) so i could get it to 48 but if i used a 14t pinion per say i would be doing 30ish. So basically i geared up so i could get the most out of the motor with out having to go up on cell count. does this make sense

any better suggestions? i will settle for in the mid to lower 40s if i can run not so hiigh and give the motor a break.

squee my question for you will there be heating issues/run pretty hot with my setup and using a 20t pinion because it is so high(the pinion). Or no matter what diffs i go with (hb or maxx standard) the pinion being 20t should not overheat the motor is this what your saying. is it hard on the motor to gear it like i previously said (maximizer diffs, slipperential, 36t spur, and 20t pinion) is this bad for the motor thanks

The setup I suggested...It should get you to about 40-43 mph on 4S w/ the buggy diffs and 20/36 gearing. Personally, I would go for 5S with a 8XL.

squee will the 20t gear no matter what bog down/overheat my motor with the hb or the maximizer diffs basically is a 20t pinion to much to handle for a 7xl and will it create heating issues. thanks

i would say yes, with the high gearing. But hitting 50 on only 4s is a lot of starin IMO. You would be pulling juice pretty good with the higher gearing. You would be better off going 5s.

neweuser what is the highest pinion (lower than 20t) that i can get to have safe running temps and not as much strarin on the motor. thanks

With the speed that you are trying to get, you will need to sacrafice some of that to get less strain by gearing down. So in all, you will not get to the 50ish mark. You can drop your pinion size yes, but you'll lose speed. If you go 5s, you won't need to worry about it so much. But even hitting the 50ish mark with 5s is hard to do and have a reliable, efficient system that won't get hot. You could go 8xl with 5s and be pretty close though depending on the gearing.

i man i will scarifise speed i will accept mid to lower 40s and i will drop the ponion size can i reach this new speed level with a less strained motor also what is the pinion size that gets me about to here(this new disired speed) with not verymuch strain on the motor and cooler/more reliable running also any thoughts about a fan and how i could atach it. thanks

would it be better(for cooling) if i went with the 7XL 540 and the rc monster heatsink(would also hold on the end of the motor) would this be better cooling than the already built in heatsink in the 540c version.

The Feigo would be better cooling people say as it has the attached heat sink. but really, if you want a "cool" system, go with like the 7xl on 4s should be good. Throw a fan on the esc, heat sinked motor, and you should be fine. this would also depend on gearing, what pinion you use, the spur, the pitch of both, your weight, many things.

I am defiantly going 4s no matter what an my truck will weigh a little less than stock. i want to at least stay in the 40s consistently and reliably. that is my goal. also i want a pinion that will get me here without straining the motor and running cooler(than it would with a 20t). Also i want to know will the motor(7XL 540) run cooler with the smooth can and RC monster heat sink, or will the 7xl540c w/ built in heat sink run cooler. I want to use 36t spur and maybe 18t(if it runs noticeably cooler than 20t) pinion do you think this will be as much stress on the motor as the 20t or do you think stepping it down 2 teeth on the pinion helps it run cooler and more efficient.

Ok, here is what I ran to give you an idea. I ran the 10xl on 5s geared 18/51 mod 1. You can use the Feigo 540 7xl with the 4s. what slipper are you using?

revo slipper and slipperiential

someone would need tochime in here as I'm not familiar with the Revo slipper. But I would think you would want like a 44t and 16t pinion

The biggest spur for the Revo is a 40T. Also, why would you want a 44T? Thats to big...Your gonna need to go as small as possible on the spur and probably as big as possible on the pinion if you go with the Slipperential...Anywho, I would go with the buggy diffs, a 7XL, 4S LiPo, and somewhere around a 18T pinion. You should get around 39 mph without the tires ballooning (if the tires balloon slightly, you will gain a mph or two...). With a 20T, somewhere around 43...That should be about right...

Why? Because as I said, I do not know the Revo slipper and what it takes and would hope you would chime in! LOL, also, henever specified what this is going into? Anywho, I was thinking the 36 would be too small and the gearing would be too high....

take a look at this thread it will give you a better idea of my future set up and see if you can tell me if you think the motor will run cooler than it would with a 20t ad more efficient and reliable. Thanks

You should be good with an 18t

Well lets put it this way. You will need about 1200 watts of power to get to the
50 mph mark. If you run 4s with the drain on batts 3.5v per cell =14 volts.
You be drawing about 85 to 86 amps to get 50 mph.
If you go 5s. It will have less amp draw to go 50 mph at 1200 watts.
But even if the cells are still 3.5 volts. The amp draw will only be about
68 amps. For no matter how much gear you put on it. It will still take
a certain amount of wattage to get the speed you want to run.

i gave up the 50mph goal

i am just now trying to run the 7xl cool and efficently on an 18t pinion.

So you in the test mode now. Let us know.

You should be happy. 50 is nice, but not totally needed for most applications.

I'm aiming for about 55 mph with my BPP LSP. Thats with normal gearing as well :D.