6XL on 4s - RC-Monster Forums

Nick · **6XL on 4s -** 04.06.2007, 06:02 PM

I was thinking of a 6XL on 4s, at the moment I run a 7XL on 6s which is great and have another truck I wish to run less on.

What do you think to this motor combo? I'd probably get a Quark too.

04.06.2007, 06:18 PM

Personally, I think that a 7XL on 6S is too much. I also think that the 6XL on 4S is too much. The 7XL on 4S would be about perfect for a MT or buggy, if you want speed. Otherwise, the 8XL on 4S is very practical on 4S giving good performance and speed. What are you going to run this in? If you are really going to be pushing the motors like that, you might want to consider a "better" motor, like a Lehner or Neu.

Serum · 04.07.2007, 02:52 AM

7XL on 4S is perfect, i am assuming you are using it on 6S Lipo and not A123?

the 6S setup needs another motor. a 9XL or even higher would be a wise choice. I am pretty sure the 7XL will get burning hot on 6S.

Nick · 04.07.2007, 05:20 AM

The 7XL doesn't get as hot as people think on 6s Lipo and I don't really want to lose the speed it produces by going to a 9XL and a Lehner is over my budget at the moment.

I will try the 7XL on 4s but do you have suggestions on a different motor? Like to try something new as I've had a 7XL in my other truck for a while now.

zeropointbug · 04.07.2007, 05:47 PM

Quote:

Originally Posted by Nick

The 7XL doesn't get as hot as people think on 6s Lipo and I don't really want to lose the speed it produces by going to a 9XL and a Lehner is over my budget at the moment.

Is that a joke? That's like pushing that motor way past it's ideal limit. 5s LiPo is the limit in my books.

BrianG · 04.07.2007, 07:17 PM

You could gear the 9XL to have the same speed as the 7XL, and it would keep the motor under the 40krpm sweet spot...

Patrick · 04.07.2007, 10:00 PM

Quote:

Originally Posted by Nick

The 7XL doesn't get as hot as people think on 6s Lipo and I don't really want to lose the speed it produces by going to a 9XL and a Lehner is over my budget at the moment.

How long do you run it for on 6s and what sort of driving? What gear ratio do you have and what sort of heatsinks/fans do you use? This is in an e-maxx is it?
Without a big fan my 7xl get pretty hot after a 5 minute race on 12 cells.

Nick · 04.09.2007, 09:43 AM

Quote:

Originally Posted by zeropointbug

Is that a joke? That's like pushing that motor way past it's ideal limit. 5s LiPo is the limit in my books.

No it's not a joke. :)

The 9920 has twin fans and the motor just has the RCM heatsink. It's geared high, I think 20/51 and I don't get any problems. The ESC gets hot but by no means dangerous (before the fans I couldn't get a 5min run without it thermalling). The motor stays warm. My average speed is 40 though, so nothing really pushing it, I just like the power and speed there for when and where I need it. ;)

Finnster · 04.09.2007, 01:52 PM

Quote:

Originally Posted by Nick

No it's not a joke. :)

The 9920 has twin fans and the motor just has the RCM heatsink. It's geared high, I think 20/51 and I don't get any problems. The ESC gets hot but by no means dangerous (before the fans I couldn't get a 5min run without it thermalling). The motor stays warm. My average speed is 40 though, so nothing really pushing it, I just like the power and speed there for when and where I need it. ;)

are you sure on that? My 8XL geared 15/51 or 16/51 gets into low 40s on 14 cells or 4S. On 5S its just shy of 50mph.

A 7xl/6S/ and 20/51 gearing should be (way) faster unless its way overgeared and can't get upto speed. This is an Emaxx in 1st gear then?:eek:

tallyram · 04.09.2007, 08:36 PM

read the post again. his average speed is around 40. the truck goes faster, it probably goes ballistic on 6s!

Finnster · 04.09.2007, 08:47 PM

Quote:

Originally Posted by tallyram

read the post again. his average speed is around 40. the truck goes faster, it probably goes ballistic on 6s!

I'm trying to make sense of what he meant. Was at work so only had time for a quick read. My truck's avg speed is zero, as it mostly sits at home. :)

Seriously tho, worried about losing speed vs "avg" speed of 40 mph..

Mostly cruizing, with occasional blast back to 1955?

Patrick · 04.10.2007, 05:23 AM

Quote:

Originally Posted by Finnster

Mostly cruizing, with occasional blast back to 1955?

Great Scott!
What is it Doc?
We need more gigawatts for the flux capacitor!

BrianG · 04.10.2007, 10:34 AM

"Heavy!"

"Why do you keep saying that? Is there something wrong with the Earth's gravitational pull in the future?"

:)

Nick · 04.10.2007, 08:55 PM

If the field is big enough I can push early 1953-1954. ;)

But yeah, I cruise about at 40mph usually, I haven't clocked top speed yet.

Finnster · 04.12.2007, 05:59 PM

Quote:

Originally Posted by Nick

If the field is big enough I can push early 1953-1954. ;)

But yeah, I cruise about at 40mph usually, I haven't clocked top speed yet.

That would be a fun test. :) Drag that next to Johnny's duallie and we really would be talking about gigawatts.