Moving from Monster to Buggy

[yuri]

Hi all, I´m sad to say I´m selling my e-maxx, the new one, with all the money I´ve spent on it it´s a sad decission but... I´m switching to buggies. I´m tired of driving almost alone on the local tracks and of having little (if any) competitors on my scale, nearly everyone around here owns a nitro buggy so I think it´s time for a bit of asskicking with a brushless setup that, althought won´t be able to run on official races, at least could fight against them when they are practicing.

So here is the big deal, what to do with all the things I own? The truck itself it´s going to be sold along with its hopups and replacement parts (a lot of them) and my Mamba Monster is going straight to the buggy,the hard part comes now. I own 4 packs of MaxAmps 2s 6000mah and two more packs of MaxAmps 2s 8000mah, and I don´t know if I could use them on my new setup, I´d prefer to sell them and buy some a123 packs (I´d love to have them quickly charged and saying goddbye to hardazous lipos) but don´t know if there is any a123 pack that would fit a buggy and be fine for the Medusa-60-2000 I already own.

Also I´m still not sure about WHICH buggy use in my setup but I think I´ll end with the RC8 since it´s sold in a nearly hobby store and that way it will be easier to find parts for it. But that is, don´t know anything about that car and don´t know if there is any a123 pack that would fit and power the Medusa quite well (racing against nitro, remember?), and in case it isn´t if I could use the lipo packs I have or I´d better sell them and buy another ones, or even if I should buy another motor... aagh I´m lost.

This is going to be a long conversion I know but I´m sure I have to make it since I love this hobby and the only bad thing I have to tell about it is the lack of Monsters enthusiats I´ve found around my house (living in Spain).

Some advice?

[Serum]

Hi Yuri, fellow European.

A buggy will be a totally different ride than a monster, it just goes into the direction you point it to. It's great compared to a monstertruck, much more predictable.

The A123 packs need to be used in 2P to get the buggy some power. (they tend to drop in voltage under load pretty bad) lipo's deliver more power, weight-wise.

Mike has got a mount for the RC8, in case you need one.

[yuri]

So I´d better use lipos? And would my packs have any use in a buggy? If I intend to run the Medusa in 4s that would be two 6000 packs on the car and I don´t know if there is any way to fit both of them at the same time on it.

I´ll keep looking around this forums...

[Serum]

The 6000 packs of maxamps don't hold their voltage too well either, the 2 2S2P 4000mAh packs you've got can be best used in series (4S2P) to get you the best voltage/power. Allthough these packs might be a little on the heavy side.. don't know what your goal is; one batterytray or two batterytrays?

with one tray the height of the two 8000 packs might be too much.

[yuri]

Still don´t know about my goal neither, that´s the problem, don´t know even what car I´m using... The motor mounts I´ve seen seem to use one side of the car so that would led to a single battery tray, And I guess that having enough voltage with a123 and being at least 2p would mean to have a great bunch of cells on the car... so maybe I´d better forgot about a123-

I guess you refer to my 8000 packs when you talk about the 2S2P 4000mAh packs, that would be changing the connections so I have those 2s2p isn´t it?

[Serum]

No, no need to change the packs; the 8000mAh packs are 2S2P packs, made with 4000mAh, obviously resulting in 8000mAh.. :)

I'd prefer a lightweight pack. (such as a good quality Enerland based pack used in 1P) For an MT the A123 might be the right choice, or if you run them in 10S, the voltage under load becomes less of an issue; since you are going to use the mmm controller, you won't go over 6S. While some might consider this a good solution, i don't. I simple don't like it if the cells drop too much in voltage. It means more stress for the cells, more heat. (so less efficient as well)

[yuri]

Won´t 1p have too much drop? And where could I find those Enerland based packs so I can see what sizes are we talking about?

It´s not a problem for me to sell the batteries and spending some money on new packs, what I need is a setup that stands against nitro buggies and with quite good runtimes (hey, wasn´t it what almost everyone wants around here?

[BrianG]

With a little creativity, you can fit dual 2s2p 8Ah packs in the buggy, but really need dual trays to maintain body clearance. But you need a special mount where the motor is on top, or maybe have it on the front side opposite the servo. Either way, it can be done. I did a Hyper 8 with those exact packs and it works well (for me anyway).

If you have some flexibility, you may want to consider a Truggy instead. There is a lot more room under the body for various battery options, but you may need a slightly bigger motor to help with the added weight.

[yuri]

The truggy doesn't seem a good idea for me, don´t want to repeat the error I made with the monster.

I´ve checked your conversion on the Hyper and it looks quite good, wonder if the RC8 has so many space as the hyper seems to have. I think it will be more balanced too and since I can make my own motor mount in my workplace with no cost I´ll consider seriously this option, 2 battery trays and center motor mount.

By the way doesn´t a so tall mount give you problems of meshing? I mean in jumps maybe the motor would move more than in a low motor mount and maybe it´s easier to bite some dents of the pinions...

So the 8000mAh packs seem to be a good idea, their only fault would be its weight, isn´t it? Maybe an alternative would be some 5000mAh packs from some other vendor, two of them in series?

[BrianG]

The mount Mike made for me is very sturdy. I'm currently using steel spur and pinion, but even when using the pastic spur I had no problems whatsoever.

Yeah, the 8Ah packs are kinda heavy. A set of 5Ah 2s1p packs may be a better choice for weight and height (body clearance). Depending on how aggressive you are gearing and who makes the lipos, you may have to monitor battery temps since the C/Ah rating combo may not be enough to deal with the current draw.

If you need more runtime with a smaller Ah pack, dual 3s1p 5Ah packs (6s total) would be perfect on the appropriate motor and geared for ~35mph.

[yuri]

Well, I'm trying to make up my mind, I want to run the higher possible voltage, best option would be 6s, now I have two choices for the car, one of them is a used rc8 in very good condition with the king headz options on it for about $225, the other one would be a brand new xray808, they are saying lot of good things of this car, and I know if I choose the rc8 and it doesn't fit my expectatives I will be groaming why didn't I bought the 808.

Furthermore I like the displaced differential on the 808 that would allow a better weight balance with a 6s pack...

Advice? Is there any way to fit a 6s pack in any of these?

Edit: the pq4350 6s seems to be a good option since it's "only" 166x46x46 and I've been told those are some of the best batteries around...

Also forgot to ask if the medusa 60-2000 would be usable with this voltage, I guess it's not since it's getting to 45000 rpm...

[yuri]

Sorry to repeat myself, if anybody could tell me if the differences in those cars make it worth to have the 808 even thought I´d need the parts to arrive by mail when I need them I would be very grateful. Also I´m nearly sure I´ll buy some 6s 5000 packs from poly RC, I would use single tray in the 808 but not sure on the rc8, so if you could confirm me that the medusa would be too fast on 6s that would be great so I can start thinking of selling it and getting some 1600 or even a neu.

Thanks in advance to everyone, and sorry again.