Project Evo

[Xtreme R/C]

Hey everyone.

I'm geting ready to start my project "EVO" , I'll be geting the Gorillamaxx G2R X-brace chassis kit for the REVO when it is released.

I plan on picking up a NEW Revo to start with and selling off all the nitro related parts on ebay, keeping the front and rear assemblies for the EVO.

I want to use either an emaxx tranny with the gorilla single speed conversion or a center diff style setup with either a diff or solid drive and a oneway front driveshaft. I'm not shure what my gearing and motor options will be with each setup, and how much room is between the chassis rails on the gmaxx chassis. I realy want to do the center diff style setup to keep the center of gravity as low as possible.

What I realy need help with is what brushless/controler/LiPo's to use. Before I found this site and forum I was thinking Novak or Hacker, but it looks like there are way more and better options out there. I know MaxxAmps can build me 8000 mAh packs, any other/better options out there?

My goals:

1. Needs to be fast, lol :D
2. Needs to make a 30 minute long race, preferably on one pack.
3. To out accelerate, out handle, and out run any nitro MT out there.
4. To be as light weight as posible, most race Revo's around here are 8-9 lbs.

Any help would be greatly appreciated.

[coolhandcountry]

What do you call fast? Mike is going to have the front and back rears. You won't need a revo for the conversion. I can 25-30 minuntes run time on 9xl with gp3700 18cells.

[nbcaznmaster]

wut speeds u be getting?

[Serum]

With the goals you have got in mind i think you are a good candidate to step up to lipoly's! (weight might be an issue with 18 cells)

[Xtreme R/C]

I do want to go LiPoly. I was thinking 4cell lipo, a little more voltage than two 6cell Nimh packs. I can go 5 or 6 cell if I have to but that's more wight considering I'm gonna have to double up the cells in series to get the capicity to go 30 min.

What motors should I be looking at? and what kind of voltage do they like to be run at?

As far as speed, this is going to be a race truck. On an off road track you most likley will never hit more than 35 MPH on a straight, it just needs to get up to that as quickly as posible, ;)

Lipo cells are 1/3 the weight of Nimh cells, if i remember right. So even if you build a pack with 4 cells in series and 2 or 3 in parallel (4s2p or 4s3p), it would weigh a ton less than the equivilent voltage in Nimh cells, which allows you to gear higher for the lack of weight, and lets the vehicle accellerate or decellerate faster because there's less mass it has to move. Because the truck weighs less overall, there's also good chance you'll be able to jump further, but that's your call.

35mph? I think that'd be easily do-able with a 7xl and a 9920 controller, you'd theoretically be able to even run 6s lipo on that motor, but that would prob. be too much power (if there is such a thing)........it'd be an amazing sight though. :D

[Gustav]

I'd go for a stop in a 30min race and carry half the battery weight.You'd still be at an advantage compared to the nitros in terms of stopping time.

Money permitting i'd go with a lehner 1930/8 hi-amp and a micro controller on1p4s with pitstops/battery changes,for lightweight and hence more efficiency.(the more weight you carry the more mahs you're going to need to carry it).

EDIT;and run fans on motor and controller,the temps towards the end of such a long race could be an issue.

[MetalMan]

Generally, a Lipo will be about 1/2 the weight of NiMh in the same power rating (voltage times amps). For example, Kokam 4s 3200mah is ~400g, and a 12cell GP3300 pack is ~780g. If you don't need all the power that a GP3300 (or higher) has to offer, then you could get a Lipo pack that is smaller that would suit the current that the motor requires that would be ~1/3 less weight than GP3300 (for the same voltage).

[Xtreme R/C]

Thanks for the info and idea's, I'm open to any and all sugestions.

If the Lehner is the better motor, I don't have a problem spending the extra cash. Where can I find the specs on all of them?

Can someone give me a short explination on the s-l-xl of the motors. For a MT do I need to go with the L or XL.

Does the 9920 have BEC? I would like to not run a reciever pack if at all posible, to save on weight. And does it have some kind of low voltage cutoff?

[Papa]

The following two links will get you to lehner info.

Lehner BK
Bk Lehner


Keep in mind Mike can and will get you these products.

[coolhandcountry]

I would run the ubec. the 9920 has a bec but it don't work on high cell count. here is a site to http://www.bk-electronics.com/ The xl is a longer can with longer armature to make more torque. I like the xl motor. Mike runs a 1940 in one of his trucks over the other motors. That should tell you something. I have been runnig a smaller one around to test out. I can see a difference in the lehner motors.

[Xtreme R/C]

I searched for the ubec, and read up on it, I'll be geting one of those. I'll probaly get two, one for my LST so I can run my 7.4V lipo rec pack I got from maxxamps.

Is the the 1920, 1930, or 1940 series Lehner similar in size and torque to the xl?

[coolhandcountry]

ARe you talking lehner xl or feigao xl? The 1940 or 1950 is closer to the feigao. The 1930 is closer to the lehner xl. The lehner 19 series run better magnets and have a little more quality in the motors. I think the ubec is the stuff to. :D

[Xtreme R/C]

Originally posted by coolhandcountry
ARe you talking lehner xl or feigao xl? The 1940 or 1950 is closer to the feigao. The 1930 is closer to the lehner xl. The lehner 19 series run better magnets and have a little more quality in the motors. I think the ubec is the stuff to. :D

I was looking for a comparison between the lehner 19 series and the feigao, Mike sent me a PM with the details.

So right now I'm looking at a Lehner 1940/9 or 8, a 9920 controler, 5 cell LiPo at 8000 mAh, a UBEC, and a couple of fans to keep everything cool for 30 min. Oh, most likely a monster heat sink also.

That sound about right?

Is the 9920 the best way to go for a controler?

[nbcaznmaster]

yep 9920 is best valuue, though since u seem like you have unlimited money, go for one of the hgiher bk controllers!