A step to far? Need advice........
 

So i got my Losi 8ight project pretty much complete. Just got to install the CNC shock towers.

CLICKME

All is well, I have the 4S pack plugged up and the plan was to run it on that power for the season.

Well, like most plans, there's often a change. My change came whilst sniffing round the net for Lipos, I ended up buying a Thunder Power 5000 6S Extreme-V2 pack. Call it a spontaneous purchase.
So the postman delivers it this morning. Oh dear God, what am i to do with this behemoth of a battery? :surprised:

It's a battery to die for but seriously tall. So now I can't get the body shell on and am wondering if I shouldn't do a complete rewrite of the plan and go with the Losi Truggy instead.

Before i do that though, I wanted to first run this by you guys......

Is 6S too much power anyway? Sure, it'd be a blast, but I'm wondering if this amount of power is just useless?
My other option is to just Ebay the battery away and stick with the original 4S plan.

I await some qualified advice :smile: Thanks :mdr:

http://www.mkeeler.com/models/8ight/8ight_done_01.JPG

Just pick a low kv motor and go for really long runtimes...

The motor is 2kv now (8XL) but that's not the question.
If the 6S with my 8XL is already too much to be able to handle race-wise, then I won't go to Truggy just to run it and will simply ditch it.

I simply can't run the 6S in the buggy because it's too tall and I'd have to cut a hole out of the bodyshell to let it poke out. NOT good in a roll.....

I guess I didn't understand the question. You asked if 6s is too much power. The answer is yes and no. :smile: Yes if you run a fast motor, no if you run a properly matched motor and gear right. HV is always more efficient than high current, so if you can utilize the 6s, then I would go for it if you can.

The only way I can see the big 6s pack fitting in the buggy is if you take it apart and re-wire for dual 3s packs and put them on each side of the CD. Of course, then you'd need a mount that lets the motor run in the center and over the CD. A truggy has a lot more room in the body so that's ok.

Right. I see where you're coming form with the voltage versus current thing.

Reworking the buggy to accomodate saddles is clearly a no go. Even if I managed to get a mount made to run the motor over the CD on it's centreline, the body would then foul on it meaning I'm back at square one with even less money in my wallet lol

I think even a 4s could be a tight fit - the 4s 4800mah 20C pack in my Hyper 8 almost hits the body. If I pushed on the body slightly, it contacts the battery.

Even if you could get it to fit, 6s 5000mah Lipo would just be too much to use on a track, especially with an 8XL, IMO. I run a Neu 1512/2.5D (also about 2000 kv) on only 4s Lipo, and although it's geared for only ~35mph, it could easily be geared up for 40mph (which is plenty for many tracks). My point is, 4s is enough, and I wouldn't go any higher than 5s on a 2000 kv motor geared for 45mph.

Thanks metal Man.
Appreciate the input
Marcus

That is sick!

VERY clean instal man! Looks awesome!

6s will spin the motor faster than the 35000rpm peak causing excess heat and motor failure, yes, 6s is too much for a 8xl

I don't know how much different the buggy chassis is compared to the truggy, but I've raced with a guy that used 6s flightpower 4900's (140MM/44MM/63MM) lying on their side in his truggy, and had plenty of room to spare. Buggy body might still be a problem, I'm not sure.
He was using a 1700kv motor on 6s and it was over kill for our track (not so much in top end, but acceleration). An 8xl will definitely be more than you need in a buggy.

Weight is also a consideration. While its prolly lighter than a 4s2P 8000 mah Maxamps pack some might use, its still rather heavy, esp on a buggy chassis. This sounds like its race oriented, so the extra weight may really throw you off.

How long are your mains you are looking to run? I would pick a battery that has just a bit more juice than you need (say, by 20%) as any extra capacity is extra weight you are carrying for no good reason other than to make the car sloppier.

EG. Some of the truggies I've seen burn about 7.0-7.5 Watt-hours/min in a race. IDK what a buggy needs, but somewhat less. So for a 10 min Truggy race you need a ~75 Wh battery. Now, just pick the voltage you want to run, and then divide to est the pack capacity needed. Ie, for a 6S pack you need a ~3.4 Ah battery. For a 4S a 5Ah batt. 8S, a 2.5Ah battery. Obviously then make sure the C rate is high enough for you power demands, but that too will scale with needed capacity so it shouldn't be a prob.

I would guess that batt would give you a solid 20min or more. If you don't need that much think about trading it, if you need it, great. If you need more, well... you may need a batt swap. g/l.