1:10th to 1:1 comparison power.

[donhd04]

Originally Posted by losikid

Tell me, about how small can that lsx be as a running engine. Dimensions?

I kinda just inferred it, but our 1:10 scale motors are not 1:10 scale of a real engine. We'd have to go to like a 1:5 scale rc motor to get a more similar scale of size.

The LSX engine is a all aluminum 454 small block engine based off the corvette LS7 engine. Has a new deck height of 9.6 inches allowing it to fit in the new corvette with the injection system installed as a replacement engine. It's the highest hp crate engine ever offered by GM. It has actually 620 hp straight out of the crate. With just a few tweaks and 180* headers it will push 720 hp easily. Stupid amounts of hp in a small package. Just what everyone wants isn't?

[losikid]

Originally Posted by donhd04

The LSX engine is a all aluminum 454 small block engine based off the corvette LS7 engine. Has a new deck height of 9.6 inches allowing it to fit in the new corvette with the injection system installed as a replacement engine. It's the highest hp crate engine ever offered by GM. It has actually 620 hp straight out of the crate. With just a few tweaks and 180* headers it will push 720 hp easily. Stupid amounts of hp in a small package. Just what everyone wants isn't?

This don't answer the question. Gimme some dimesnions...

a 5th scale electric motor is like 4" long and a 2.5" diameter....so scale up it be like 40" long and 25" in diameter. So were talking close to the same size.

[Meatwad]

Power vs. weight ratio is the best option when trying to compare. But that would leave you at a boring trigger pull. Get almost any halfway decent bl sensored setup and it'll have you on your lid anytime you want.

Scale realism is mostly for visual interpretations, not so much function.

[Harley]

Originally Posted by donhd04

I was hoping you would chime in. Your thread on motors for the wraith is what got me thinking about this. The rig I'm comparing to is roughly 3700lbs and has 720 hp. I'm liking the .8 - 1.0+ power range in a motor. I guess now the question is what motor is out there that is going to make that kind of power using a 11.1V 3S lipo and BEC? Are we talking the new NeoPuller from Holmes, tekin pro 4, or maybe something from castle creations? And are we talking making the switch to brushless and sensored?

That 720 LSX isn't likely getting anywhere more than 500 to the wheels, likely less. There is a great thread on pirate with the guys with these big 500+ hp trucks showing dyno numbers at the wheels. It's amazing to see 500+ motors show 200-250 hp at the wheels.

A Tekin Pro4 motor is much more scale power than anything your going to compare it to in the real world.

[ThunderVP]

Sloppy is right on with his scale conversion. 1/10th scale in weight is the same as 1/10th scale in volume, a factor of 1000.
If you have a cube 10 x 10 x 10 units this is 1000 cubic units. 1/10 scale would be 1x1x1 or 1 cubic unit.

If you made a 1/10th scale model of a 20 gallon gas tank, would you expect it to hold 2 gallons of gas? The volume of 2 gallons would be larger than your entire 1/10th scale vehicle.

So if you go with the power to weight ratio, since 1/10th scale weight is a factor of 1000, horsepower should be the same, so that 600hp would be 0.6hp or 450 watts in electric conversion. That's about equal to a 14turn brushed or 4600kV brushless.

[donhd04]

Originally Posted by ThunderVP

Sloppy is right on with his scale conversion. 1/10th scale in weight is the same as 1/10th scale in volume, a factor of 1000.
If you have a cube 10 x 10 x 10 units this is 1000 cubic units. 1/10 scale would be 1x1x1 or 1 cubic unit.

If you made a 1/10th scale model of a 20 gallon gas tank, would you expect it to hold 2 gallons of gas? The volume of 2 gallons would be larger than your entire 1/10th scale vehicle.

So if you go with the power to weight ratio, since 1/10th scale weight is a factor of 1000, horsepower should be the same, so that 600hp would be 0.6hp or 450 watts in electric conversion. That's about equal to a 14turn brushed or 4600kV brushless.

Now we r talking. This is exactly the information i was asking for First off I'm definitely no where near knowing what I'm talking about When it comes to electric, I'm a pure idiot on the subject. I can change a ceiling fan and thats as about as far as it goes. So when y'all talk watts and volts I get lost quickly but I'm starting to catch on. Now back to the 14T brushed or 4600kv brushless. Is brushed measured in turns and brushless measured in KV?

[donhd04]

Originally Posted by Harley

That 720 LSX isn't likely getting anywhere more than 500 to the wheels, likely less. There is a great thread on pirate with the guys with these big 500+ hp trucks showing dyno numbers at the wheels. It's amazing to see 500+ motors show 200-250 hp at the wheels.

A Tekin Pro4 motor is much more scale power than anything your going to compare it to in the real world.

Harley I wish I was smart enough to figure out how to post a link to a video of it from my IPAD2 but I don't. I do know it has a high angle brand drive line, atlas 4.0 transfer case, front and rear stear, 4:56 gears, front and rear 14 bolt centers with custom made Rockwell outers with 40 spline axle shafts. It probably be safe to say that at least 600 of the 720 hp is getting to all 4 wheels. I could be slightly off a little though. I'm not so much worried bout actually keeping it scaled as much as I'm wanting that equivalent of power to weight ratio. I love that explosive power initially but want it all thru the trigger pull and I'm not wanting a 100mph XO-1 type speed. I'm wanting about a 12-15 mph top speed but I want to pull a baby in a red wagon across the yard type power and torque. To me in a 1/10th crawler/racer doesn't need to go any faster than 20 at the most. That 15 mph range will get me the tire speed I want to climb unbelievable hills and still have torque to crawl with. So your expertise and opinions are very valuable to me on this. Before I forget thanks for all the info.

[Grizzly4x4]

Originally Posted by Harley

That 720 LSX isn't likely getting anywhere more than 500 to the wheels, likely less. There is a great thread on pirate with the guys with these big 500+ hp trucks showing dyno numbers at the wheels. It's amazing to see 500+ motors show 200-250 hp at the wheels.

A Tekin Pro4 motor is much more scale power than anything your going to compare it to in the real world.

That's because most chassis dynos calculate horsepower from acceleration. The big tires and wheel weight has more inertia and therefore is harder to accelerate.

Horsepower is a bogus thing to compare, it can't be measured. You can only calculate horsepower from torque or acceleration.

Torque is the true measurable rating that people should be looking at.

With that said, I agree power to weight ratio is the best way to scale things down.

[Grizzly4x4]

Originally Posted by donhd04

I do know it has a high angle brand drive line, atlas 4.0 transfer case, front and rear stear, 4:56 gears, front and rear 14 bolt centers with custom made Rockwell outers with 40 spline axle shafts. It probably be safe to say that at least 600 of the 720 hp is getting to all 4 wheels. I could be slightly off a little though.

Drivetrain losses are going to be at least 30% in a 4x4, more if the transmission is not very efficient.
Realisticly your vehicle is getting 500 horsepower to the wheels and a chassis dyno will show a bit less because of the inertia of the tires/wheels. At sea level of course, you lose power with altitude as I'm sure you know.

[donhd04]

Originally Posted by Grizzly4x4

Drivetrain losses are going to be at least 30% in a 4x4, more if the transmission is not very efficient.
Realisticly your vehicle is getting 500 horsepower to the wheels and a chassis dyno will show a bit less because of the inertia of the tires/wheels. At sea level of course, you lose power with altitude as I'm sure you know.

Inertia is compensated by gear ratios. Of course the lower the gears the easier it is to start the movement of an object.

[donhd04]

So with all this being said, what motors are on the market or made to custom specs that have the most power to weight ratio. If my rig weighs 5-6 lbs what motor is get me close (per say) to what I'm asking for power wise. And if you can speak in laymens terms please so I can understand.

[Harley]

Originally Posted by donhd04

Inertia is compensated by gear ratios. Of course the lower the gears the easier it is to start the movement of an object.

These rigs have a lot of loss in the power train. Rockwells are going to be huge power sucks in a rig like that too.

Honestly a regular 27-35 turn motor on 3s is going to have more torque then it's scaled up counterpart. Again because of the differences between electric and gas it is a different world that you can't really scale the same way.

[Grizzly4x4]

Originally Posted by donhd04

Inertia is compensated by gear ratios. Of course the lower the gears the easier it is to start the movement of an object.

No, you compensate for the tire height with gearing. You can add a bit more for inertia but most people don't add enough. Especially when you get into big heavy 40"+ tires.
Dyno your rig with heavy tires and then light tires and see the difference.

The point is that measuring horsepower by using angular acceleration is flawed.

Originally Posted by Harley

These rigs have a lot of loss in the power train. Rockwells are going to be huge power sucks in a rig like that too.

Honestly a regular 27-35 turn motor on 3s is going to have more torque then it's scaled up counterpart. Again because of the differences between electric and gas it is a different world that you can't really scale the same way.

I totally agree with Harley. I have a 12lb scaler that on 11.1V (3S) with a 35 turn motor performs like a full size with 600-700 hp.

In a 5lb rig you would want to be under 35 turns. Maybe a 35 turn handwound on 7.4V (2S) LiPo.

[ThunderVP]

Originally Posted by donhd04

Now back to the 14T brushed or 4600kv brushless. Is brushed measured in turns and brushless measured in KV?

You will see brushless motor specs listed by kv (1000 rpm per input volt) or also in turns. The turn listing for a brushless is differant than turns in a brushed motor. (ie a 35T brushed is similar to a 21T brushless) The power output of the 14T brushed / 4600kv brushless I mentioned would be using a 2S pack. If running 3S or higher that will of course raises the output of higher turn motors.

As others have been discussing, gearing plays a big factor on performance. Lower turn motors have a higher RPM output and could be geared with a higher reduction ratio to get the same wheel speed output of a higher turn motor.

Along with the crawlers I own, I also build and compete in R/C truck and tractor pulling competitions. I have a 4x4 Wheelie King puller running a 6900kv Castle motor on 2S and it pulls 40+ lbs on dirt in a pulling sled. It can easily pull an adult in a wagon at 10+ MPH. Its geared around 35:1

[donhd04]

Originally Posted by ThunderVP

You will see brushless motor specs listed by kv (1000 rpm per input volt) or also in turns. The turn listing for a brushless is differant than turns in a brushed motor. (ie a 35T brushed is similar to a 21T brushless) The power output of the 14T brushed / 4600kv brushless I mentioned would be using a 2S pack. If running 3S or higher that will of course raises the output of higher turn motors.

As others have been discussing, gearing plays a big factor on performance. Lower turn motors have a higher RPM output and could be geared with a higher reduction ratio to get the same wheel speed output of a higher turn motor.

Along with the crawlers I own, I also build and compete in R/C truck and tractor pulling competitions. I have a 4x4 Wheelie King puller running a 6900kv Castle motor on 2S and it pulls 40+ lbs on dirt in a pulling sled. It can easily pull an adult in a wagon at 10+ MPH. Its geared around 35:1

DAMN!!!! thats alot of power in a RC. thats what i want but i highly doubt that battery that you are running will fit on my axle mounted battery tray along with my servo. What model number is the motor that you have? I really like castle creations and holmes hobbies motors. I have read alot reviews on TEKIN motors and most of which said the same thing. They were disappointed with the ouput of the motors saying they were good just not game changers. So i was lead back to CC and HH motors on that note.

[donhd04]

Originally Posted by Grizzly4x4

No, you compensate for the tire height with gearing. You can add a bit more for inertia but most people don't add enough. Especially when you get into big heavy 40"+ tires.
Dyno your rig with heavy tires and then light tires and see the difference.

The point is that measuring horsepower by using angular acceleration is flawed.

I totally agree with Harley. I have a 12lb scaler that on 11.1V (3S) with a 35 turn motor performs like a full size with 600-700 hp.

In a 5lb rig you would want to be under 35 turns. Maybe a 35 turn handwound on 7.4V (2S) LiPo.

thats what i have now but with the stock axial 55t motor and 11.1v 3s lipo. Im already wanting a tad more wheel speed. Correct me if im wrong but i really don't want to go lower turn on a brushed than 27T or 21T and more than likely not even that low. I scared of loosing most of the torque at initial take off. Am i correct in saying that?

[Meatwad]

Originally Posted by donhd04

DAMN!!!! thats alot of power in a RC. thats what i want but i highly doubt that battery that you are running will fit on my axle mounted battery tray along with my servo. What model number is the motor that you have? I really like castle creations and holmes hobbies motors. I have read alot reviews on TEKIN motors and most of which said the same thing. They were disappointed with the ouput of the motors saying they were good just not game changers. So i was lead back to CC and HH motors on that note.

You, sir, have not read much about tekin's pro4 motors. About the same power output as castle's 14xx series but sensored for low speed crawlability.

[Jeep-Power]

Originally Posted by Coops

As far as an electric conversion, check out this if you haven't already seen it.

WORLDS FASTEST street legal ELECTRIC CAR - YouTube

friggin' awesome-- 10.5 sec. @110MPH

Someday....

[Harley]

Originally Posted by donhd04

DAMN!!!! thats alot of power in a RC. thats what i want but i highly doubt that battery that you are running will fit on my axle mounted battery tray along with my servo. What model number is the motor that you have? I really like castle creations and holmes hobbies motors. I have read alot reviews on TEKIN motors and most of which said the same thing. They were disappointed with the ouput of the motors saying they were good just not game changers. So i was lead back to CC and HH motors on that note.

No castle motor is a good choice for a Wraith. A sensors motor is the only decent option. Tekin is really the best option for brushless.

[donhd04]

Originally Posted by Meatwad

You, sir, have not read much about tekin's pro4 motors. About the same power output as castle's 14xx series but sensored for low speed crawlability.

Ive read and watched.
Tekin Pro-4 sensored 4-pole 540 4000kV brushless motor tested - YouTube