8ight T 9XL

Hey guys,

I've seen a bunch of posts wherein guys are asking about setups and what they should go with. There is much talk of wanting power and talking about going with huge motors and/or 5S or 6S lipo.

Many guys asking basic questions and proposing a particular setup that they want to build, have no idea of what to expect from a brushless system.

When I went to large scale electrics, I ran the gambit of available hardware just to find the combo that would be right for me.

Anyway, I wanted to post this video. The truck is a Losi 8ight T, the setup is a Quark Monster Pro running a Feigao 9XL with a Maxamps 4S2P 8000mAh pack geared a rather mild 14/46. I want to add that the Mamba Max that I also run in the truck also gives the same level of performance with the two pole motor.

I know that there have been other videos, but I wanted to post something of a relatively mild setup that will give many hours of enjoyment and fewer headaches than running something hotter. Please bare in mind that my 8 year old son was on the camera and I'm running this in my front yard which is grass and sand (filling in after Katrina) so traction is low.

http://s154.photobucket.com/albums/s...DSCF0303-1.flv

My personal opinion is that performance is more than adequate for bashing and very fast for a small to medium size track. It may even do well on a large track, if there are only nitro vehicles running. LOL

[BrianG]

Nice truggy; seems to go quite well!

Love the kid's commentary: "Can you stop for a minute, I have to go pee really really bad". ROFL.

[glassdoctor]

Very nice... looks much like my CRT setup with a 1700kv Neu motor (about the same kv as the 9xl)

Yours actually looks faster... mine is geared just a little lower yet.

I've been preaching the same thing about the motors.... these milder sub-2000kv setups are very good.

[glassdoctor]

Originally Posted by BrianG

Love the kid's commentary: "Can you stop for a minute, I have to go pee really really bad". ROFL.

That was classic!! :D

[Finnster]

Very nice truck, and I would have to agree. I find it hard to use the full potential of my 8xl on 4S alot of the time when driving in rough off-road areas. ~40mph is very very fast when you are flying at little rocks and debris that's just waiting to nail your truck and send it flying. On road the extra speed is nice, but then your diffs hate you. :)

I think part of the focus has been to get nitro-equiv top end, but more and more I don't think its needed. The brutal acceleration BL offers more than makes up for it. While 35mph may not immediately sound impressive to the nitroheads, losing a bit on the top end vs hotter setups to get the TQ and reliability is a good tradeoff.

Very few times when I've been barreling thru a const site have I wished I was going 50mph. :)

[aqwut]

I like video..

[zeropointbug]

Love the video AAngel, in particular the commentary! :005:

What can I say? I kid is a kick. You should have seen the look on his face when he reaized that the video on this digital camera had audio too. It was priceless.

The performance of the 9XL class of motors is perfect. In fact, I do have my 1512 1.5Y coming back from Neu and I'm already wishing that I had gotten a 1700kv motor, although the 1900kv motor won't be too much hotter.

The believe the value of the video is that it shows useable power. If it had anymore, it wouldn't have been hooking up at all. With what it has now, it still gets a little nuts, but not stupid.

The truck does rip pretty well. The really cool thing about it is that I could still go with 5S, if I did want to get stupid.

In comparison to a nitro setup, there really is no comparison. The acceleration of the brushless setup is brutal. It doesn't have the very top end of some nitros, but the nitros take so long to get there that you never see it on the track on during a bash session. Not only that, but if they do gear for that kind of top end, they sacrifice a lot of bottom. With the brushless, I could easily have dropped in a 5S pack or simply regeared to 16 or 18/46 and that would have had any nitro guy tossing his truck into the nearest garbage bin.

I was at the LHS yesterday and a friend of mine was telling another customer about my truck. He told the guy about a time that we were on the track. I was running my 9XL setup and he was running his CRT with a Rick Brick (what ever that is) mod engine and I SMOKED him coming down the straight. I'm not just saying that I beat him down the straight. I mean that once we got to the sticky part of the straight and I got on the throttle, I left him like he was standing still. By the time his engine wound up, I was at the end of the straight. He tells me that he paid over $400 for that engine.

The point...you don't have to get insane; and as a point of interest...the video was the last of three runs that lasted a few minutes each. As you could see, I was pushing it pretty hard. When I shut it down after shooting the vid, the esc temped at 115 and the motor was a 190. A hotter motor (Feigao) would easily have temped way over 200. This is of course, with the cheapie Feigao motors, but the correlation in temps as you decrease the number of winds applies with any make of motor.

[jhautz]

I'm thinkin you could have dropped that motor temp a little by gearing it up a few teeth. I find the XL motors can run much longer before overheating if you find that perfect "sweet spot" on the gearing. They are much more sensative to both over and under gearing. The Neu and Lehner motors just have larger usable gearing ranges before heat becomes an issue. But if you get the gearing just right, they can run a good long time without getting to the critical temp range.

I have a 9XL on 5s that I can run just as hard for much longer than a few minutes before the temps get that high.


But I do agree. Most brushles setups are WAY overpowered. Much more power than can possible be put to the ground.

jhautz, if the esc temps are so low, are you saying that I should just keep gearing up until the motor temps come down? I'm only just starting to play with the lower kv motors. I started at 16/46, but the temps were just as high on that gearing too. Should I try 16/44 or 18/46?

[zeropointbug]

I agree, if I ever raced R/C (not one near where I live), that would be a good setup as far as power available. But yeah, those motor temps you have seem awfully high for that setup.

IIRC, it was 15c out the last time I ran my truck here (over 1 month ago) and I had my 7Xl running 16.5v A123 (~4s lipo) geared 18/51 and had crazy power, ran it very hard, the highest temp I saw was 155F.

Well, I know that my motor temps are high, but it is also hot down here. In the 90s easily. I was out at the track a couple of weeks ago and I temped the bedliner of my truck at 115*F.

[jhautz]

Originally Posted by AAngel

jhautz, if the esc temps are so low, are you saying that I should just keep gearing up until the motor temps come down? I'm only just starting to play with the lower kv motors. I started at 16/46, but the temps were just as high on that gearing too. Should I try 16/44 or 18/46?

Yea just add a tooth or 2 and check the temps you get. The ESC should go up a bit and the motor temps come down. You will know when you go to far cuz the esc will start getting too hot. I'm not saying push the temps on the esc, but you should be able to runn hotter than the 115 with no issues. i have been running the MM in my buggy lately and its been running 140F with no issues at all. I typically shoot for finding the gearing where I get just slightly lower temps on the esc vs motor.

[bdebde]

It would be worth a try see if temps come down with more gear. I was beginning to wonder if I was ever putting enough of a load on the motor in my 8lb buggy when running XL motors. Now I have 7.5lb buggy that seems much happier with a "little" 1930 Lehner.

[zeropointbug]

This whole brushless motor gearing issues (or limitations) just reinforces my theory that we need RaserTech's AC Induction motors. 100% usuable gearing range... would also be much more tolerable to high temperatures.