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a little underwhelmed by performance - looking for fixes

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rflx

Member
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Location
Germany
Driving Style
Basher
Hi everyone!

My 4s LiPo has arrived and i have taken the new MT410 to the forest. I had a lot of fun, and my custom shell had a tough time.
However, I am not yet happy with the overall performance. I decided for a short wheelbase RC because i wanted to do wild stuff that my short course cannot do, like standing backflips. Those are out of the question, though. The best i can do from a standstill is roll the truck on it's back like a turtle. While i managed some frontflips during jumps by pulling the brakes right after lift off, backflips won't work during jumps either. I was also hoping to see backflips off of logs laying around, but no dice.
Looking at videos, people seem to have very granular control of angular momentum during jumps, and can easily rotate the truck in either direction. I am not yet an experienced driver, so my control is probably lacking. But it just seems like i don't get that kind of response from the truck at all, no matter what i do.

I'm not sure where i start adressing this, so i was hoping to get some pointers from you guys. Is 4s just not enough power? Do i have the wrong tires? Too much drag from the body? Any input is appreciated.

Some technical specs:
-Hobbywing ezrun max8 ESC (punch set to 5/5)
-Tenshock X802 v2, 2200kv motor
-15t pinion
-Proline Badlands 3.8
-Goldbat LiPo, 4s, 5000mAh, rated 55c
 

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Tires have a huge effect on aircontroll, the badlands 3.8 are light and ~small. Great for ground performance, but are not very agressiv in air. If you want to make the thing flip like mad get some 170mm tires like the backflip 6s. I also think you can get a bigger pinion on 4s 17-18t should be fine (punch down to ~2-3).
https://www.modellbau-metz.com/rc-modellbau/arrma-rc-dboots-back-flip-mit-6s-reifenset-verklebt
Thanks. Those are the tires i was originally looking at (but got the badlands with the truck 2nd hand).
It looks like the Backflip MT tires are about 20mm wider (diameter) than the Badlands. The Badlands also don't seem to balloon much (at least compared to the dboots i run on my short course). Will the MTs do more ballooning as well, or is it just a difference in size/weight?
Will the (much cheaper) Backflip LP tires give me a similar effect, or are those too small/too light?
 
LP's will have more effect than the badlands, you can also look in the new belted badlands mx38 hp.
 
I don't think the belted MX38's will help with air control as it's the ballooning of the tyre that gives it momentum for flips etc.
Your probably better of with normal MX38's I think..??

That's why I'm going to start off with Copperhead 2's on my build, they are taller and wider than Badlands..??
 
Use the non belted badlands MX38’s or 3.8 trenchers non belted. As long as your battery is good you should be able to pull that no problem. If not up the center diff weight. Start with 200K and go from there. You may be diffing out as your front tires come off the ground. (That’s what it’s designed to do)
 
I don't think the belted MX38's will help with air control as it's the ballooning of the tyre that gives it momentum for flips etc.
Your probably better of with normal MX38's I think..??

That's why I'm going to start off with Copperhead 2's on my build, they are taller and wider than Badlands..??
Phew, another 100€ for a set of MX38s. Maybe i will postpone that until may. Would you guys recommend the MX38's over the Backflip MT's?

Brian, I seem to remember you having experience with the Backflip LP's. Do you think they would also do what i'm looking for? They are so much cheaper...

The center diff is at 150k at the moment, so i guess i should only adress that after a tire switch.
 
Phew, another 100€ for a set of MX38s. Maybe i will postpone that until may. Would you guys recommend the MX38's over the Backflip MT's?

Brian, I seem to remember you having experience with the Backflip LP's. Do you think they would also do what i'm looking for? They are so much cheaper...

The center diff is at 150k at the moment, so i guess i should only adress that after a tire switch.

i think you have 3 possible adjustments to do:
1/ thicker fluid in you central diff, some guys go up in the millions
2/ bigger pinion will give you more speed = more air control with same tire mass (watch your temps)
3/ bigger tires (same effect on temperature)

i would do them in that order since they are from the cheapest to most expensive.
 
There are a couple reasons for this:

1. 4S is likely not enough power, with my ET48.3 it would never do a backflip on 4S certainly not off of a small tree stump or curb etc.

2. the makeshift "bodyshell" you have their will be a little aerodynamically blunt and will make it harder for the truck to rotate because of the extra air resistance.

The badlands will be heavy enough and will balloon just the right amount for doing tricks, there are tyres that are more suited to tricks such as the bigger and heavier Arrma Backflip (non LP standard model) however I believe it is better to run more power rather than heavier tyres as tyre/wheel weight can dramatically affect handling.

I would suggest buying a 6S battery and running a lower punch of 3-4 as this will be enough punch without being too harsh on the drivetrain or power system.
 
I use the 4s backflips wheels and really like them so far. I can wheelie for over 100 feet no problem and easy flips too on 4s running arrma BLX motor and esc. You did buy this used. Maybe the diif fluids are low or spiders gears maybe worn down and slipping. Same for the gears.
 
Allright, i will order some 500k diff sirup and a 17t pinion. Probably a motor fan as well, since the Tenshock is getting pretty hot at 4s/15t already. I'll solder a connector to try 6s with two of my 3s packs before ordering another lipo. Thank you all for the input!

I guess it's also time to drill some holes into the lexan shell and send the cardboard body into retirement :cry:
 
I saw your post on the Arrma forum too and regardless if it is a 6s Outcast or Kraton or an MT410, I agree with @Klappars that 6s is the way to go if you want easy back flips. Wheelies can easily be accomplished with 4s but backflips are way easier on 6s. The MX38 tires will also help greatly once the car is in the air.
 
Allright, i will order some 500k diff sirup and a 17t pinion. Probably a motor fan as well, since the Tenshock is getting pretty hot at 4s/15t already. I'll solder a connector to try 6s with two of my 3s packs before ordering another lipo. Thank you all for the input!

I guess it's also time to drill some holes into the lexan shell and send the cardboard body into retirement :cry:
I just put my first hard bash on mine today and it was insane on 4S. Standing backflips no problem. Would be uncontrollable if the suspension wasn’t absolutely amazing on this truck. You need to check your systems settings and TX. My max 8 hobbywing 4274 2200kv makes this thing nuts.
 

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I just put my first hard bash on mine today and it was insane on 4S. Standing backflips no problem. Would be uncontrollable if the suspension wasn’t absolutely amazing on this truck. You need to check your systems settings and TX. My max 8 hobbywing 4274 2200kv makes this thing nuts.
Couldn't agree with you more. (y) I was babying the truck first few times out running 4s and Arrma BLX185 motor ESC combo and it rips. I'm sure 6s would be insanity. I have a Arrma Kraton 6s and that is pretty wild but that truck is not nearly as tight and well proportioned as the Tekno. Has to be something with the throttle setting he has going thats holding him back.
 
I just put my first hard bash on mine today and it was insane on 4S. Standing backflips no problem. Would be uncontrollable if the suspension wasn’t absolutely amazing on this truck. You need to check your systems settings and TX. My max 8 hobbywing 4274 2200kv makes this thing nuts.

I agree I think its probably a settings issue. You should be able to do flips without a problem with that electronic setup.
 
I just put my first hard bash on mine today and it was insane on 4S. Standing backflips no problem. Would be uncontrollable if the suspension wasn’t absolutely amazing on this truck. You need to check your systems settings and TX. My max 8 hobbywing 4274 2200kv makes this thing nuts.
I don't know what TX stands for :oops: And not sure what you mean by system settings. ESC & Transmitter? What would I be looking for?
What tire size & pinion are you using with that motor?
 
TX stands for transmitter RX stands for reciever ??

I think you need to check your sec settings, have a look in the manual that came with the esc and it will explain about the punch setting,
As I starting to think your punch setting is set too low..!!

http://www.hobbywing.com/products/enpdf/EzRunMAX8V3.pdf
 
TX stands for transmitter RX stands for reciever ??

I think you need to check your sec settings, have a look in the manual that came with the esc and it will explain about the punch setting,
As I starting to think your punch setting is set too low..!!

http://www.hobbywing.com/products/enpdf/EzRunMAX8V3.pdf
Thanks for clearing up the abbreviations! Throttle end point and throttle dual rate are set to 100% on my transmitter. All other adjustments didn't seem relevant to the problem, so i only messed with steering end points so far.
I did check all esc settings with a program card after buying the truck. I changed the punch to 5/5 after my first run. That resulted in lots of wheelies on most surfaces, but did not enable flips.
I agree I think its probably a settings issue. You should be able to do flips without a problem with that electronic setup.
Watching this video again, I noticed Vas mentioning that he cannot pull off a standing backflip on 4s either.
It's not like the MT is super weak. Acceleration/speed feels similar to my (lighter) 3s car. I can drive 5ft up a tree (nature's ramp) and i'm having loads of fun doing stuff like that. The truck just doesn't want to flip like i expected.

For you guys who can pull (standing) backflips on 4s: Would you mind sharing what tires & pinion you are using?

Again, thanks for all the help!

 
Last edited:
What diff fluid are you running in the rear. A heavier oil in the rear will lock it up more and get that front end to pop up more.
 

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