9L Vs 9XL performance in Emaxx?

[Rtsbasic]

Hi, I was wondering what the sort of power difference is between the two motors on low voltages - 12/14 cells. I have both motors although the 9L is in a different car at the min, and figured the motors lighter and revs higher..so I can get a better top speed but will it have all the same crazy torque? To conclude, I'm happy with my 9XL performance, but was wondering if theres any advantage to be had with a 9L on 12 cells.

Cheers.

[Sylvester]

The 9xl would be the best bet because it would run way cooler than a 9L. You gear up on the 9xl for speed and still have torque due to the longer can. Pretty much just stick with the 9xl and ditch the idea on the 9l. A 9l would be good fora buggy, not a maxx.

[Rtsbasic]

Thats pretty much what I thought, thanks for confirming that, I'll leave the 9L in my RC10GT.

Only bit that bothers me is on 12 cells it has no real top speed, on 20/51 its around 25-30mph. Plenty of torque & accel, but I can't gear any higher. On higher voltages it has a much higher top speed, but for general mucking about I don't see the point in putting more cells than needed in.

[swiftneed]

Why dont they refer to 9L as a 540 9l / 9xl / 9L / 9turns / which one is cooler or hotter so confusing for the new folks like me, which one is better to run on 12 or 14 cells or wait maybe they r talking about the 1950 L who knows, I want to make a purchase but which one is going to give me longer runtime and which one is it ouch:007: :020:

[neweuser]

Swift - I believe the 9xl will run cooler and give better run times, but on 12-14 cells, i owuld get the 7 or 8xl. But it depends on the batts.

[BrianG]

I think there are a few reasons for the difference in L vs XL (or vs S for that matter):

1. Efficiency. There is an ideal rpm range where each motor is at its most efficient. To get that RPM, you apply the required voltage based on the kv value. Since an XL motor has a lower kv for a given turns count, you would need more voltage to get that ideal rpm. Running an XL with the same voltage as an L of the same turns won't be as efficient.
   
2. Weight. Well, of course the XL will weigh more, not to mention the battery weight for the higher voltage requirements.
   
3. Cogging: A lot depends on the controller firmware, but if you use a low kv motor on low voltage, it isn't going to spin very fast and the controller may have a harder time to read rotor position at low speed driving.
   
4. Power matching. For a relatively light (6-9lb) truck, you probably don't need tons of torque, so an L will suffice. Just like an S size works for 4-6lbs, and an XL works well for ~9 and up (to a limit of course).

That's my $0.02.

[swiftneed]

Thanks Brian and Neweuser this forum is great and always willing to help out,all you have to do is ask , I am kinda settled on a xl3600 or the 9xl with a 9920bk or MGM 16016 bought the bec and have the gp 3300 7cell already have the cvd and wish i had enough to get the g3,thanks for the info guys and this forums moderators make this a fun hobby. Still a project in progress. Yesterday I decided to put a 7cell gp3300 on my t4 wow with the ss5800 this thing was flying with no problems just a little warm on the motor but fun.:027:

[swiftneed]

Maybe I should just wait for the xxl thats new any suggestions

[squeeforever]

The XL3600 would fry the controller. Especially on 14 cells....My XL3100 ran hot on 12. Get the 8 or 9XL.

[coolhandcountry]

If you run like 12 cells. I would go 7xl. The 7xl can take more cells to if you choose.

[Rtsbasic]

swiftneed, the 7XL or 8XL on 12-14 cells will be very impresive. I run my 9XL on 14 cells now and love it.

Only thing that concerns me is the ESC gets pretty warm after a hard run with a 9XL, i'd hate to think how hot it'd get with a 7XL, without any forced cooling.

[neweuser]

Just run a fan on it. I have run a 10xl and 9xl on 16 cells and did fine. If I were you, run the 9xl. you can gear it up and it'll stay cool. If you are sticking with just 12 cells, go with the 8xl. Then you could run 12 or 14 without problems...i always run a fan on the controller as extra insurance. They're not all that heavy, fairly cheap, and hell, why not?

[swiftneed]

Thanks guys I live in new york and the temp are now in the 60s definitely dont think the temp is going to be a problem I am leaning toward the 9xl but the esc has me concerned would like to get one, I dont want to buy two just one to hopefully later use on more cells currently 14cells.

[swiftneed]

So u guys r saying the fiego 540c 9xl for my emaxx how about the xl3600

[squeeforever]

The XL3600 would fry the controller. Especially on 14 cells....My XL3100 ran hot on 12. Get the 8 or 9XL.

Maybe this helps......