MP777 SP2 Brushless

Ok, so for those of you who viewed my thread questioning buggy weight, here is the beast:
Details:
Kyosho MP777 SP2
Losi 8ight shocks
Ofna Spider center diff
Novak HV4.5 brushless system
Century 9T mod1 Pinion (from Tower Hobbies)
Aluminum Battery Boxes
Pictures:







The buggy currently weights 7.4 lbs without batteries and the battery boxes are designed to fit Maxamps 2s 10000mAh batteries (will hold 2 batteries for 4s total voltage).
Due to the weight issues, I might convince myself of 5000mAh batteries, but the verdict is still out.
I calculated that my battery boxes weight a combined 0.6lbs, so I figure I can thin them out (mill/cut off un-needed sections) and save maybe 0.2 lbs.
I have a few other things I am going to try to save weight with, hopefully getting the buggy down to 7.0 lbs without batteries.
I have yet to finish the battery straps (velcro based) and I still need to mount a short antenna post.
The "o-clamp" motor mounts are from megamotorsusa and I cut the Novak heatsink down and mounted a fan on it to try to keep the heat down.
My plans for this buggy is mostly as a basher, but I also plan to take it to a local track to "race" (they probibly won't let me accumulate point for their championship, but I really just want track time.)
So... How bad is it?

[MetalMan]

One thing to consider, many of us are using Mamba Max ESCs which weigh 2.5oz. according to Tower. The HV-Maxx ESC weighs 4.8oz. That's a 0.14lb. difference (not enough to account for the weight difference you're seeing, though).

How much does your buggy weigh as a RTR nitro with/without fuel?

[cart213]

You need to get rid of those Tamiya connectors and get something to handle the amps, like Deans. I can't understand why Novak would put those crap connectors on their brushless system.

[jhautz]

First things first..... Ditch those white battery plugs! Get youself some proper deans plugs (or other high current connector).

Other than that it looks like it should do nicely for you. Nice job.

How is that century pinion holding up. I didn't have much luck with those lasting very long against a steel spur. They worked well on the plastic spurs though.

Referencing the mamba maxx:
It isn't rated for 4s, and I want to stay within manufacturer recommendations, additionally I am not going to wait for the MMM which was due out 2 years ago initially.

Referencing the connectors:
I will be changing to deans, I just haven't yet.

Referencing the buggy weight in Nitro form:
I don't know, I bought it as a roller but kyosho advertises it as 7.5lb, I do not know if that is with or without fuel.

Edit:
As for the century pinion: I don't know yet, I haven't had this thing running yet, between the cold/snowy weather, and the lack of good batteries, I have yet to turn it on.
Thanks for the input

[gixxer]

I also didn't have much luck with the century pinions on a steel spur. I tried it in my crt.5 and it only lasted 2-3 runs.

[bdebde]

I got one run with a century pinion on a steel spur. Get a Kyosho plastic spur or RC-Monster hardened pinion

[mwry13]

Originally Posted by cmcclive

Referencing the mamba maxx:
It isn't rated for 4s, and I want to stay within manufacturer recommendations, additionally I am not going to wait for the MMM which was due out 2 years ago initially.

Referencing the connectors:
I will be changing to deans, I just haven't yet.

Referencing the buggy weight in Nitro form:
I don't know, I bought it as a roller but kyosho advertises it as 7.5lb, I do not know if that is with or without fuel.

Edit:
As for the century pinion: I don't know yet, I haven't had this thing running yet, between the cold/snowy weather, and the lack of good batteries, I have yet to turn it on.
Thanks for the input

as far as the mamba max goes... its rated for 4s with a suitable BEC... they dont say it in the manual but they imply it in the manual ( i believe it went like anything above 3s, a External Bec is required ) and in fact it works quite well with a nice little novak fan on top of it.

and 7.4 pounds without batterys? damn mine weighed that with batteries if i remember right... ( not sure, but definatly lower than 8 lbs.)

[Hydrodancer]

That diff could be adding some weight. And, your deffinetly going to need a chassis brace in the rear if you plan on jumping this this.

Originally Posted by Hydrodancer

That diff could be adding some weight. And, your deffinetly going to need a chassis brace in the rear if you plan on jumping this this.

Why would the diff be adding weight? because of the metal spur? or is a spider heavier then a regular?
As for the rear chassis brace, I know, I am in the process of making one, the stock one won't fit with the motor being centered.

[jhautz]

That weight sounds reasonable to me. My buggys are generally in th 8-8.5lb range fully loaded with lipos.

[lincpimp]

The century pinions are not hardened (not enough to work with a steel spur). Get a kyosho plastic spur, it should fit that diff just fine, 46t should be you best bet. Also you may want to upgrade the novak to a 5mm shaft rotor. I broke my hacker c50 maxx 1/8 motor shaft yesterday and others break their novak shafts too.

Otherwise the buggy looks good. I would find a way to tie the tops of the center diff bulks together, it will help the pinion/spur mesh stay more consistent.

Originally Posted by lincpimp

The century pinions are not hardened (not enough to work with a steel spur). Get a kyosho plastic spur, it should fit that diff just fine, 46t should be you best bet. Also you may want to upgrade the novak to a 5mm shaft rotor. I broke my hacker c50 maxx 1/8 motor shaft yesterday and others break their novak shafts too.

Otherwise the buggy looks good. I would find a way to tie the tops of the center diff bulks together, it will help the pinion/spur mesh stay more consistent.

I am going to work on the center diff brace, not sure if I will buy and mod one, or just make one, I will upgrade to the 5mm shaft once they are available, but last I checked they are still "order pending".
Additionally, I am thinking of getting the kyosho spur and trying to modify it to fit the spider diff, as the century gear wasn't the best choice I guess.

[bdebde]

There is always the RC-Monster hardened pinions with a bore adapter for your 1/8th inch shaft. Then they will also work when you go to the 5mm shaft.

Originally Posted by bdebde

There is always the RC-Monster hardened pinions with a bore adapter for your 1/8th inch shaft. Then they will also work when you go to the 5mm shaft.

I picked up a 12T RC-Monster pinion last week, but I have read that the Novak motors require smaller pinions to prevent overheating, so the 12T will be for if I want to make a speed run or two, while the 9T (if I change to plastic spur) will be for regular usage, unless my results differ.

To update, I have shaved around 1.5 oz (total) off the battery boxes, they look a bit weaker now, but they should be fine, I might even change over to plastic boxes (would save me another 1.5 to 2 Oz.) but that would be either A) more cost or B) lots more time, as I would be machining them at home (using a drill press and dremel).
I have ordered a few more parts:
-CF Diff brace that I will need to trim to fit into place
-front chassis brace (which I will use in the back, hopefully)
-kyosho 46t pinion (will try to modify it to fit the spider for now)
-stronger front shock springs (they are curently using the stock 8ight-T springs, so rear should be ok)

Hopefully, this weekend I will find time to:
-Swap out the battery connectors for deans
-Remake a few of my small aluminum parts out of UHMW (wont crack and ~1/3 as heavy as Alu), that should save me an once or so
-I need to mount the antenna still (probibly use a small piece of UHMW to make a mount)
-Make up my battery straps (I have the materials, but haven't gotten to them yet)

Anyone else notice any small modifications I have yet to do?