E-Savage build

[fb5b]

Ok since retiring from onroad and cleaning my forum ettiquite up a tad (ok a lot) I have been working on an E-Maxx killer.

At present it runs 2 * 2S2P A123 packs through a Mamba Max ESC to a Medusa V36-50-3300V2 motor (4 pole brushless so more torque than a 2 pole Feigao XL / HV MAxx system etc) Upgraded GCM BL Chassis, Cen alloy shocks, Traxxas E-Maxx driveshafts etc etc

GPS (Navman on the back) comes in at 54kph at present with an 18t pinion but I think that's vastly undergeared as the motor barely gets warm. New ESC is coming in soon and possibly widening the car's stance some to help handling.



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[fb5b]

Pic one, outside.

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[fb5b]

Under the hood.

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[obzELiTe]

never thought of a gps to measure speed.
do navman give % error +/- on speed the way they do on accuracy of position?

[KingBob]

We've clocked one of Maxd Outs emaxxes doing 106 kph infront of a radar gun.

[remotebandit]

We've clocked one of Maxd Outs emaxxes doing 106 kph infront of a radar gun.


uhhhm , i think that equated to $13 per kph if rumours of how much he spent on it are true ... lmao .

[bazz]

my maxx was runnin at 78kph i think just for racin at west coast. i think your first problem is that its a savage. hahaha. that 78 was not even geared up . i was there when maxd out s maxx went 106, pretty hairy....... you tend to shit yourself a little when something that big goes past that fast.

[remotebandit]

King ... i stand corrected .. lol .

Does anyone have any video of maxdouts runs .

By the way , the savage looks good fb

[KingBob]

Especially when he tried to brake and it just started spinngin out of control towards the kerb!

[KingBob]

The reading on the radar:

http://members.iinet.net.au/~canison/106.jpg

Also have a quicktime clip of the actual speed run here: (6mb)

http://members.iinet.net.au/~canison/106kph.MOV

[fb5b]

What sorta Motor / Battery combo were they running though? What I find is over 60-70kph you lose driveability and efficiency. And as I am sure RB can attest, a 9XL on 4S Lipo is more than a handful and thats only a 55-65kph combination.

[obzELiTe]

at that speed there is no driveability, u just need to try and keep it in a straight line.
foams help, rubber tires just expand way to much.

[KingBob]

Thats why he ran foamies. He did try rubber tires, i think i have a photo or video of them ballooning up somewhere.

And he wasn't running lipos, just good old NiMh's.

[fb5b]

I found that Nimh just couldn't handle the amps the Medusa motor wanted, the A123 cells have a 30C discharge rate (60C burst) which from a 4600 pack is quite nice, plus they are safer than Nimh and Lipo and you can charge them at 10amps without any problems!

[remotebandit]

Jesus fb , love the cells , where did you get them from , im only running 20C and looking for an upgrade

[KingBob]

Well Maxd out did that speed run using good old 3300's. Of course he did have 4 packs in it, but they were still just 3300's. And if memory serves the motor was a Hacker.

[Maxd out]

fb5b nice ride , would like to do another speed run myself
, I started on my truck prep about 2 weeks ago with truck ready for a run in about 4-5 weeks , this time 10s lipo & some really big gearing will easily see the truck hit 130+

[Wilkinson]

Sounds like a Speed Comp could be setup :D

[KingBob]

Hahaha, i'd love to see that e-savage against the current crop of monster trucks who race in perth. It'd get thrashed.

[remotebandit]

10s Lipo .....

* RB just died in the ass and fainted

[Matt]

The video didnt work for me Rob, do you have it in any other format other than poxy Apple Quicktime (.MOV)?

[KingBob]

Nope, just quicktime.

[Maxd out]

Current world record speed in a savage http://www.youtube.com/watch?v=77GiK3YmCD8

[Maxd out]

current emaxx record
http://www.youtube.com/watch?v=cK7J1w4TYfA

[fb5b]

Jesus fb , love the cells , where did you get them from , im only running 20C and looking for an upgrade

RB I got the cells from www.a123racing.com

I run the 2 * 2s2p packs in the E-Savage

and a 2s1p pack in the TT-01

They are far safer than Nimh or Lipo but still have that punch the Lipos have, check youtube there is an example of someone putting a drill through one of these cells and still no explosion!

And KB, I'm not looking to compete with people who spend $5-$6k on their E-Maxxes but show me someone who has spent similar coin to me ($1200 to date) from the ground up and I dare say I'd be competitive. Lets compare Apples with Apples mate
<span class='smallblacktext'>[ Edited Thu May 22 2008, 08:43AM ]</span>

[obzELiTe]

i wanna see the 130 run for sure

[KingBob]

And KB, I'm not looking to compete with people who spend $5-$6k on their E-Maxxes but show me someone who has spent similar coin to me ($1200 to date) from the ground up and I dare say I'd be competitive. Lets compare Apples with Apples mate


Actually "mate", the current crop of MT's running do only cost that much since they're converted gas truggies. I don't think anyone is running an e-maxx anymore.

[SuperRoo]

http://www.finedesignrc.com/ct-losi.asp

I saw one of these the other day the guy bought for $1200 landed in Aus with a spare set of batteries packs. Top speed and acceleration is insane which is pretty scary considering how much it weighs. Its a absolute weapon.

I've also seen a new Emaxx with a pair of TP 5400 lipo's, new wheels & tyres and a slight gearing change pulling speeds well in excess of 70kph which he paid under 1000 bucks for and he hasnt even had to shop out side Australia for his parts.

I wish you the best of luck with your project fb but I fear the biggest let down for you at the moment is the platform for which you started with. By the time your done I doubt you will have much left of the E-Savage and it still wont handle as good as a stock E-Maxx.

[KingBob]

I Agree Nuts, the CoG of the Savage is just too high to get the same handling. The bulk of the trucks running now have a CoG at or below the axles which means insane speed can be kept into the corners. The high CoG of the savage will cause too much roll trying to do the same move.

[Maxd out]

Its all about the build & the driver .......Not the bucks ive spent building it, Im sure your truck would be a weapon in the hands of Adam Drake & thrash my maxx

[remotebandit]

Hey maxed ( and im sorry to take away from your thread fb ) but you mentioned you pretty much line the thing up and go . Once set up perfectly as you had yours , Is there much battling with it at speed or aerodynamics takes over and its just a dart going where you point it

[Maxd out]

Areodinamics play a big role , during testing last time a maxx became airborn after a slight wind caught the front end , during my run the car feels very seated around the 70km abouve 70 the car can become very unpredictable .
Here is a pic of the truck at the time of the run with about $800.00 spent on it nothing fancy here.

btw: 24cells

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[Maxd out]

This twin didnt make the grade ,,,,,,but double as a frizbee @ 94km

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[Wilkinson]

94km an hour frizbee........nice

I think the E Revo will be a better match for the Maxx than a Savage

[fb5b]

Wow the C50 took 24 cells? What kv is that thing? The best I can probably muster in mine without too much hassle is a 6s A123 set up for 19.8 volts (within the Mamba Monster Max limit [have changed out the Mamba Max]) and the 3300kv motor would get to 65340 rpm, not sure how the bearings would go with that.

But that set up would probably push towards the 80-90kph mark and it's just a battery swap on the current set up.

[Patrick]

This car is pretty fast. It's a bit bigger and heavier than an e-maxx, truggy or savage.
He is using 8-12s with cheap $100 plane esc and a neu 1521 1.5d (1900kv). 1521's are 84mm long, 15mm longer than the 1515's Michael Guall and I use in our truggies.
http://www.youtube.com/watch?v=ZoCFgyprA8Y&feature=related This one is 5 minutes long and a bit boring at the start, so skip to 4.15 if you don't want to watch it all.
http://www.youtube.com/watch?v=E1-XCew1rCk&feature=related
http://www.youtube.com/watch?v=ERY9_TLF86M&feature=user

You don't need huge speeds to have fun with an mt though. My truggy is only geared for low to mid 50's at the moment for racing, and it does ok. ~65k's is pretty good for general bashing with good temps and runtimes. Low to mid 80's on grass is the most I've geared mine for, but there's still power left. I should get a gps to see what it's actually doing though.

I think a lot of the money that has been spent on e-maxxes has been trying to find the best setups. If we only bought our final setups, it would have a lot cheaper, especially for the first guys to go brushless.

Maxd out, what motor are you going to use on 10s? The old hacker?
I'd try running mine on 10s, but my esc only does 6s.

<span class='smallblacktext'>[ Edited Fri May 23 2008, 05:54PM ]</span>

[remotebandit]

Patrik , that could not have been put any better .

Im actually perfectly happy with how my Maxx goes , i dont know speed wise as i havnt clocked it yet but id say on 4S atm im just touching 45ks but my power has increased by over 50% and my battery life is allot more efficient so when i go 5S id be doing 55ks and to be honest with you there would be no way id be hitting off road jumps at that speed as i dont like buying spares .

In saying this , im only out for bashing and im only out for a good time not a hassle / repairing time so totally understand where some of the other guys that go crazy on them come from

[Maxd out]

Here is your chance patty ,,,, get that old maxx dusted down & borrow the 32/170 , lets see how fast you can go .....

btw: i need to borrow a big pinion from you :D

[Maxd out]

the old hacker motor ,,,,, hell yes it will go the full 9 yards with a 10s.

Patty your the ### man give us the run down as to what speeds we may be seeing .

[Patrick]

What kv is your hacker?

If I use my 1700kv motor on 10s (around 60 000rpm) I can use the gearing I started off using at racing (46/13) and it should get a bit over 106kph (the calculator is less accurate for high speeds, so it's hard to tell exactly), so we probably won't need big pinions to get big speeds. The 14t pinion you use for racing might be all you need depending on the hacker's kv, but I do have a 25t pinion if you want to try it !burnout

Opps, I was talking about the gearing in the truggies, not the e-maxx. I don't know if my e-maxx diffs will handle 10s, plus the truggy seems a lot easier to drive fast, doesn't try lifting off as much.
<span class='smallblacktext'>[ Edited Sat May 24 2008, 08:48PM ]</span>

[nonitro]

my god...now i have almost seen everything...an MT @103kmh...i thought my yokomo drifter on grip tyres with a novak 5800SS was fast. something that height and weight that fast...watch your ankles, dog and small children. thats madness.nah dirt bashing for me. good show old son.