Limitless New fastest rc in the world! Scorched Rc

[Greengaunja]

I can picture nasa holding a arrma speed rig in there hands on the moon .then another one pulls out a 8s rig and does some bashing
I wounder if someone could make a transmitter that we could manually change gears .like a 1/1 manual transmission car or truck.we would need a transmission that allows this also.

We already have it. There is one in my SCX10.iii and the Vanquish Phoenix. Operates via my RL switches and mini servos.

A guy on YouTube made one but I doubt it would be reliable at those kind of speeds

Ultra precision would be needed but no reason it can't be done.

 

[King blitz]

A guy on YouTube made one but I doubt it would be reliable at those kind of speeds

Drop that link .plz I'd like to see it.ive allways wounder if it would be possible.
So why doesn't Raz or McCoy or others try or use this then?

 

[Greengaunja]

Not a link but here you have it.

Granted, the one on the rear operates the DIG function(FWD) for tight turns. The one in the middle is the key. Shifts between a high and low gear. I use low for crawling and high for trail running

 

[King blitz]

We already have it. There is one in my SCX10.iii and the Vanquish Phoenix. Operates via my RL switches and mini servos.

Ultra precision would be needed but no reason it can't be done.

So you can switch the gears manually? How do you know when it's time to shift it into the next gear? By sound or do you have a tach on your transmitter?or a light to alert you when you can.and can you stretch that gear before going into the next one?

Not a link but here you have it.View attachment 303729View attachment 303730

Granted, the one on the rear operates the DIG function(FWD) for tight turns. The one in the middle is the key. Shifts between a high and low gear. I use low for crawling and high for trail running

Geez that first photo was scary.what a mess of wires you got going on .ever heard of zip ties or wire loom or tucking them neat lol.anyways that's cool .looks almost like the transmission in my t Maxx nitro

 

[Greengaunja]

So you can switch the gears manually? How do you know when it's time to shift it into the next gear? By sound or do you have a tach on your transmitter?or a light to alert you when you can.and can you stretch that gear before going into the next one?

If by manually you mean flip a switch, yes.
What I suggested above would only need 2 or 3 gears. You don't want too much strain on an rc motor at the start. But once it's rolling, say you get to 60mph or so, flip a switch and add more strain via gears. And once you get somewhere over 100mph flip it again and add even more strain. Instead of going big gears closer to 1:1, go alot smaller closer to 1:1.
And it doesn't work like you are suggesting. It works like this: go slow or go fast. The principal is the same though. What I've observed in my scx10:iii is I can reach a higher speed faster if I start low and hallway through shift on the fly to high. That is, of course, in contrast of starting on the high gear.

 

[King blitz]

If by manually you mean flip a switch, yes.
What I suggested above would only need 2 or 3 gears. You don't want too much strain on an rc motor at the start. But once it's rolling, say you get to 60mph or so, flip a switch and add more strain via gears. And once you get somewhere over 100mph flip it again and add even more strain. Instead of going big gears closer to 1:1, go alot smaller closer to 1:1.
And it doesn't work like you are suggesting. It works like this: go slow or go fast. The principal is the same though. What I've observed in my scx10:iii is I can reach a higher speed faster if I start low and hallway through shift on the fly to high. That is, of course, in contrast of starting on the high gear.

I see what you're saying but that's not what I was wondering.i wanted something like 5 gears like a 1/1 with the tranny to support that.then add nitro

 

[speeding_Infraction]

He

Drop that link .plz I'd like to see it.ive allways wounder if it would be possible.
So why doesn't Raz or McCoy or others try or use this then?

Here you go
www.youtube.com/@johnnyq90

My guess is that it's probably not strong enough for the forces put through regular gearboxes on Speedrun cars.

 

[Greengaunja]

I see what you're saying but that's not what I was wondering.i wanted something like 5 gears like a 1/1 with the tranny to support that.then add nitro

I'd kill for that!

He

Here you go
www.youtube.com/@johnnyq90

My guess is that it's probably not strong enough for the forces put through regular gearboxes on Speedrun cars.

And this

 

[Notoriousone]

In F1, Lemans, Indycar, and most other top racing series gearbox reliability is one of the hardest things to get a handle on.. it would be the same with our speedrun cars. The gears themselves are strong enough but keeping the gearbox together at high RPM's would be the real issue I think. Years ago I had a HPI nitro car with a two speed gearbox that shifted itself once it hit a certain speed or rpm. It had a actual slotted disk brake that was actuated by a servo also. The transmission worked well and never broke, but of course, that car didn't get past 55 or 60mph.. A completely different matter than what were running these days

 

[Tirefryer426]

There is no benefit to a transmission in a speed run car. The entire point of a transmission in a 1:1 car is torque multiplication at lower speeds. There are a lot of examples of hyper-cars and dedicated speed cars running direct drive, or a powerglide (2 speed).
Electric motors don't need it - especially if the main goal is top speed. There are some EV applications that do use a gear reduction system to help provide more torque with smaller motors - but most EV manufacturers just oversize the motors to provide the low end torque needed.
If anything - a transmission of any kind is just adding parasitic drag that you'll have to increase power to overcome.
Conjoining motors is exactly how the high power EV hill climb and drag 1:1 cars are configured. They connect them on the main shaft with a coupler, though.

 

[King blitz]

I'd kill for that!

And this

I enjoyed watching that vid.amazing

 

[DLK83]

Shifting at high speeds without some sort of synchronizer would just end in catastrophic failure of the gearbox.. I don't think there's enough room in an rc application to design something that wouldn't grenade. Maybe 1/4 or 1/3 scale would open up some possibilities, but that's getting into a whole other realm of 1 off handmade parts and countless hours of work and money

 

[Tirefryer426]

The real question here is, is there really any true benefit to multiple motors? The only two I can think of is weight and torque.
In reality, multiple motors can't make a motor go faster than it's max rpm. It isn't like a shot of nitrous in a 1:1 street tuner. But it can supply more torque to keep pushing the speed up. Meaning the speed of the rig, not the motor. The trade off would be acceleration. The added weight will make up for the required downforce as we know the body shape and wings can only create so much. Even still, it does get to a point where it's all counter-productive for the scale of the rig.
Taking all that into consideration, it's obvious where the future of speedrunning and world records is heading. There is really only two directions for it to go. Larger scale or gearboxes designed to allow gearing changes. The fact that these rigs run the same gearing from start to finish is a hold back. Anyone who has ridden bicycles, motorcycles or manual transmission cars will understand where I'm going with that. None of the above would be very good at all on one set of gears. An rc would really benefit on a speedrun with a gearbox designed to increase the strain on the motor in at least 2 or 3 shifts in gearing. If it can be done in a crawler, why not a speed runner?

NASA

The reason for dual motors is because at the time of me typing this - most single motor applications are hitting the amperage limits of the XLX2 at around 180-200mph. There may be some outliers, but thats about where we are. Specific to speed running, the point of adding the second motor and ESC is to divide the load and reduce the amperage draw allowing the car to punch through that 200mph ceiling. There will be a point where adding more motors and power systems starts hitting diminishing returns. Maybe thats anything over 4, we don't know yet. But right now, Raz's quad motor is evidence that the division of labor across 4 motors works.

Gearboxes aren't going to do anything for speed running. We aren't fighting low speed torque delivery, and we don't have issues with RPM. Cars and bicycles with a stick shift aren't the right comparison here. Say a bicycle is designed with a target top speed of 50mph. This bike would be unrideable as a single speed as the rider would not have the power available at the low speed RPM to get the bicycle up to speed. He needs the gears for the torque multiplication and ability to pedal at a certain RPM range. Same principal in a car. Electric motors don't have the same limitations. There is a reason the EV market went away from transmissions really fast. They just don't need them. The fastest EV's out there? Multiple motors, no transmissions.

All the addition of a transmission is going to do is add weight that doesn't need to be there, parasitic drag, and really just an unnecessary failure point.
There was a guy on youtube that was trying to make some sort of set up with an intermediate reduction gear, sort of like what you'd find in a clock. And he was saying man I'm really surprised Raz or James doesn't do this. Massive props for trying something new... but its just more drag in the system.

 

[King blitz]

I don't think the idea should be thrown away ..I think maybey with more thought and design just maybey it might work..in this hobby the only idea that fails is the idea that was never tryed or pushed to exceed..I'm sure 20 years ago people laughed at the idea of lipos or even a brushless motor that would hit the speeds of 200+.allways room for improving the game..and no idea is a bad idea .

 

[Tirefryer426]

I don't think the idea should be thrown away ..I think maybey with more thought and design just maybey it might work..in this hobby the only idea that fails is the idea that was never tryed or pushed to exceed..I'm sure 20 years ago people laughed at the idea of lipos or even a brushless motor that would hit the speeds of 200+.allways room for improving the game..and no idea is a bad idea .

I'm not trying to a buzzkill. I'd love to see someone try and it let me know how it goes.
There are a lot of ideas that might work. This just isn't one of them. Like its literally dictated by physics that a transmission in this application won't provide any benefit. If we were having to use push cars to get them moving, it would be a different story. But they literally have so much torque we have to roll on the power slowly or use some variety of launch control. Torque multiplication is not needed.

If you can explain how I'm wrong, I'm listening.

 

[Greengaunja]

The reason for dual motors is because at the time of me typing this - most single motor applications are hitting the amperage limits of the XLX2 at around 180-200mph. There may be some outliers, but thats about where we are. Specific to speed running, the point of adding the second motor and ESC is to divide the load and reduce the amperage draw allowing the car to punch through that 200mph ceiling. There will be a point where adding more motors and power systems starts hitting diminishing returns. Maybe thats anything over 4, we don't know yet. But right now, Raz's quad motor is evidence that the division of labor across 4 motors works.

Gearboxes aren't going to do anything for speed running. We aren't fighting low speed torque delivery, and we don't have issues with RPM. Cars and bicycles with a stick shift aren't the right comparison here. Say a bicycle is designed with a target top speed of 50mph. This bike would be unrideable as a single speed as the rider would not have the power available at the low speed RPM to get the bicycle up to speed. He needs the gears for the torque multiplication and ability to pedal at a certain RPM range. Same principal in a car. Electric motors don't have the same limitations. There is a reason the EV market went away from transmissions really fast. They just don't need them. The fastest EV's out there? Multiple motors, no transmissions.

All the addition of a transmission is going to do is add weight that doesn't need to be there, parasitic drag, and really just an unnecessary failure point.
There was a guy on youtube that was trying to make some sort of set up with an intermediate reduction gear, sort of like what you'd find in a clock. And he was saying man I'm really surprised Raz or James doesn't do this. Massive props for trying something new... but its just more drag in the system.

Love this answer. I wasn't thinking faster overall, more like get faster faster. Speed runs need the length they do because of the gearing. But imagine combining the acceleration of a drag setup with the higher speeds of a speed run setup. But i just did some reading and read enough to see you know what you're talking about. Personally I would have thought an EV would benefit from a transmission, but you were right. You CAN use a transmission except it's far more practical and efficient to use more motors. And your first paragraph explained it perfectly

 

[ross_jsy]

I think the only benefit of a transmission would be getting up to speed faster without pulling too many amps. But a perfect pass/throttle timer sorts that problem out.

But as @Tirefryer426 has explained, it's just not needed. Electric motors aren't like nitros of old which needed 2/3 speed transmissions because they have a tiny power band right up top and low torque.

Worth a watch:

 

[Greengaunja]

I think the only benefit of a transmission would be getting up to speed faster without pulling too many amps. But a perfect pass/throttle timer sorts that problem out.

But as @Tirefryer426 has explained, it's just not needed. Electric motors aren't like nitros of old which needed 2/3 speed transmissions because they have a tiny power band right up top and low torque.

Worth a watch:

Thanks for that share! He really explained alot. Well worth a watch!

 

[Tirefryer426]

I think the only benefit of a transmission would be getting up to speed faster without pulling too many amps. But a perfect pass/throttle timer sorts that problem out.

But as @Tirefryer426 has explained, it's just not needed. Electric motors aren't like nitros of old which needed 2/3 speed transmissions because they have a tiny power band right up top and low torque.

Worth a watch:

I was going to mention this car specifically, but I figured it still wasn't a perfect comparison. Really clever going direct drive and just using a torque converter for slip. Really playing to the strengths of each system because internal combustion engines shine at high RPM where electric motors really perform at lower RPM.
He does explain very well the point I was trying to make at about 7 minutes in. We are already spinning tires, so there is no need to shift gears.

My 2 cents on this whole thing is that I think David and James figured out that these electric motors reach peak power closer to the middle of their total RPM capability. So we had this sudden 10mph jump in the record because the new scorched bulkhead with the Habao gears run a 2.66 final drive ratio compared to the Arma GP5's 2.8 - which if you run that through a calculator with a targeted top speed of 210 with the Arma 42/15, you get just about 10mph extra with a 40/15 pinion and spur.
So my guess would be that they have started tuning their gearing more toward where max power is created vs where maximum RPM happens. Somewhere in between those two areas as they still only have 650 amps available per ESC.

 

[Dan B.]

I was going to mention this car specifically, but I figured it still wasn't a perfect comparison. Really clever going direct drive and just using a torque converter for slip. Really playing to the strengths of each system because internal combustion engines shine at high RPM where electric motors really perform at lower RPM.
He does explain very well the point I was trying to make at about 7 minutes in. We are already spinning tires, so there is no need to shift gears.

My 2 cents on this whole thing is that I think David and James figured out that these electric motors reach peak power closer to the middle of their total RPM capability. So we had this sudden 10mph jump in the record because the new scorched bulkhead with the Habao gears run a 2.66 final drive ratio compared to the Arma GP5's 2.8 - which if you run that through a calculator with a targeted top speed of 210 with the Arma 42/15, you get just about 10mph extra with a 40/15 pinion and spur.
So my guess would be that they have started tuning their gearing more toward where max power is created vs where maximum RPM happens. Somewhere in between those two areas as they still only have 650 amps available per ESC.

I think you’re spot on. I’ve thought the same about the 2.6 diff mod as opposed to the GP5’s. I’m pretty sure they could drop even lower. I want a 2.3!