Building the FASTEST LEGO Car 

Apologies for using KM/H if you prefer MPH! The reason for doing so was to have more definition at these very slow speeds as my GPS doesn't show decimals. Here's a conversion to MPH of the final cars in each class (spoilers below)... Pure Lego Car - 7mph Rocket Car - 23.4mph RC motor Car - 26mph Thanks for watching! Will be back soon with another video (hopefully within the month) ☺

Perhaps you could partner up with someone who is more versed in building with technic lego. For starters i could see a use in suspension to offset the bumpy roads you use, and a wider track for higher stability. And there are much better wheels available in Lego. And perhaps a gym floor would be better suited as those are typically fairly large and exceptionally flat and smooth. A indoor location would also rule out weather conditions.

I bet if he and Brick Technology teamed up they’d make something absolutely insane

I bet you could find a way to seal off the floor of the car and add a LEGO fan to make the car go even faster

Honestly would have liked to see a bit more restrictions/rules as it does seem like you could have just stuck a lego brick to your existing rc car at that point and called it a lego car by how some of the final ones were propelled. It seemed less about optimising the lego part and more about building the most basic chassis and sticking a rocket on it.

You can definitely optimize your lego builds to make the car a LOT more stable

The thing I like the most about your videos is you show all the fails and problems you have with the project

The one using LEGO parts entirely was the most impressive.

48 years ago, using the same rocket motors, Estes C6-5, my friend and I built a Lego rocket car. The car disassembled in rapid fashion on the first three attempts. However, we discovered using Large Lego wheels, 2" in diameter with a 1/4" wide tread, and lengthening the vehicle to about 2' long AND using a new invention called Krazy Glue. We had three successful runs. Using a stop watch and a blacktop basketball court to measure speed, Lego Landsmasher IV went an astounding 26mph.

What your lego cars need is suspension. The Channel Brick technology has made a video where he compares different types of lego technic suspension designs. A differential would also help against wheel spin.

You certainly achieved the “Air” part of the project here @8:07. 😊

The 3:30 variant reminds me of the "Dolmette" chainsaw driven motorcycle 😁 The last car just had no chassis at all, you basically just bolted two axles to a flimsy wooden board. Just with some simple chassis building, triangulation and so on you'd have a car that survives the stresses.

1:54 "kp/h" is wrong. Either "km/h" or "kph", the "p" stands for "per" and thus makes the "/" redundant.

Tether car that goes around in circles tethered to a central post would be good to try also. There used to be a guy that brought a whole set up to Old Warden model days with some high speed petrol engined tether cars running on a circular portable road - they were quite exciting to watch.

I can't help thinking that smooth pavement would make a world of difference.

there's 2 improvements you can do first adding suspension to help the car to keep its wheels on the road (it will increase the weight, you'll need to take care about the suspension travel and lego shock absorbers aren't the best but it will absorb the roughness of the road and will improve the stability) two : don't forget to put a caster angle on your steering to improve stability the vehicle is very light so the stability is really important

Man,thats not LEGO,thats LET GO

Your biggest enemy is the bad street...

Halfway through, it seems like the lack of suspension is your biggest problem. Wow, I'm really surprised you didn't address that.

bro just looking at this makes me cry 3:10 there is such a tiny fraction of current going to those motors. Also people have made genuine LEGO cars that go faster

I've built a lego space capsule that had an actual little minifig that I could mount on a model rocket. I could send you the instructions I made with the part list if you want another fun lego project.

I dont blame you for thinking that lego does not hold up well because its plastic, but if you just look at a couple of images of lego technic, you can really get a feel of how strong lego technic can be. you just have to use it properly!

The fastest my LEGO cars will ever go is, how fast my 3-yo can throw them...

To be honest James, there’s some more one could’ve done on this by simply making a box chasis out of bricks.

Making the car wider helps with stability as well

As a kid we build lego technic cars and dragged them after a bike, to see what car could fastest before breaking. Rubberband-suspention. Wide car. Vertical lego bars with pegs, to clamp it together.

Hm maybe if you had a wider chassis and a bit of suspension it would help with the bumpiness of the road, and be able to have more control at higher speeds.

I still want that rocket power train

If you added suspension and a stronger chassis structure you could probably get a lot higher speed

He really went the trailmakers more engine more power lol

There are some very talenten Lego RU-vidrs out there that can and have designed cars with superb suspension and frame strength. I feel like a collab is needed herr

LETS GOO AN UPLOAD

When I was a kid, my brother and I used to build cars out of Legos to see if we could build one that would stay together when sent down all 11 stairs in our house. Everything was carpeted at the time so it was just a matter of them surviving going from one story down to the other. Legos seem to have been different then as most of the blocks were thicker than that and we didn't have any of those longer ones with holes in the sides either so I would say that they were more robust. The common problem was that the wheels just clipped onto these little plastic clips on the side of blocks made for that so the wheels would usually fall off and sometimes they'd pick the entire brick off of the car with them, plus we entirely broke a few such bricks at the little attachment point that clipped into the hub of the wheel. There had to have been loads of friction too since it was just a plastic on plastic bearing. The other thing that happened was that bricks would fall off of the outsides of our cars or whole sections would if we tried to put any hollow space inside the car. There were no Lego motors or any electronics whatsoever back then and this video is actually the first time I've ever heard of such a thing and now I want some! It was all push-powered stuff back then though. There were RC cars and we ruined several a Christmas/Chanukah present sending them down the stairs to see what happened, although I don't know why we didn't expect them to break even more efficiently than our Lego cars. This is obviously why we only sent a couple of them down the stairs before we realized that they'd all just immediately be destroyed. Seeing all the cool parts I could have harvested from them, I wish I still had them, although I doubt the parts really would have avoided oxidation after all these decades. All of the controllers were likely shittier back then too but I don't know since I've never owned one of these newer ones. The newest remote control thing I've ever owned was one of those cheap RC helicopters that you can fly indoors. I will say both that I suck at flying helicopters and that it was very funny to watch my cats chase and catch the helicopter.

With 4 lego technic motors (2 in the back 2 in the front) they can achieve some fairly impressive speeds

You have to add suspension to absorb the bumps of the road.

"You have to have a car with four wheels that thouch the ground at all times" C-Motor: "I pretend I didn't hear that!"

10:47 Left Bearing Block has already cracked 😂

Imagining someone finding half a Lego car with a rocket glued to it

Half way through, still objects take a lot of force to get start moving so I would have gotten something to get it started going a speed of like 2 before setting the rocket off because a lot of issues seem to be the nose dragging the back and flipping the thing side ways rather then going with it, forward.

It is actually possible to build much stronger LEGO cars. It has a lot of ways and elements to reinforce the structure.

When I was about your age (guessing) a long time ago, I also made a rocket Lego car using the little Estes A motors, and went through much the same progression. 1st car, too short, tumbled immediately. 2nd car longer, took off ok until thrust overpowered it and it tumbled at about 15' range. 2nd car v2.0 - added vertical stabilizer from rocket kit. Success...until front end exploded from road vibrations. 2nd car v2.1 -- taped front end together: SUCCESS! Car traveled straight down road until ejection charge in motor went off.

Great video but its a crime you hooked like 7 PF XL motors to the same battery box a stock lego battery box can only really power 2 PF XL motors at full power, also some suspension and Akerman steering geometry would have helped alot

1 of the most important parts to go fast = to have a good and stable chassis to start with. the way you are connecting the lego parts is not strong/stable, and a smooth surface is a must. however this again was a entertaining video

Bud, Don't ever feel silly for doing things that give us epic content :) !

Pretty nice work, James! 😃 Looking forward to see what you make next! Stay safe there with your family! 🖖😊

Idea: wider wheelbase! Also, maybe double the Lego struts. Maybe Lego 😁 Rocket car could go a lot faster if it had the servo steering (maybe with steering assist too?) And a Lego housing to hold the force of the rocket (vs hot glue).

All 4 wheels must touch the ground... ... except for when it is crashing spectacularly! 😂

You coud do so much more. Make the chassis much more durable by adding interlocking vertical and diagonal stiffening bars, add a suspension to all 4 wheels to improve ride quality, and adding a few of theese 6X2 weight bricks filled with metal for trimm and balancing everything out.

Lego make an RC motor which is probably the fastest pure lego motor, there's also a Power Functions servo, which is used to steer Lego models.

I think to solve the problem of turning at high speed, you can spread the wheels like the front wheels.

Brick Technology is proud of you!

I‘ve participated in lego dragster competition in Czech Republic. We had lego powered dragster it achieved 40 km/h. And sped up to 30km/h in 3 seconds.

In order to achieve a proper Land Speed record you have to reach the speed twice in each direction of the track

Suspension mate…that’s what you needed.

I wish you used a Lego propulsion system. Using gas feels like a cheat

Maybe glue the lego together with UHU glue to stop it coming apart to start with thats the strength sorted ,next is work on its power

You could have gotten more speed with the final test if you put more time into building the chassis and steering. The one row of technic was always going to fall apart. Build stronger and get way more speed!

3:00 the middle motor is spinning the opposite way as the two outer one are rotating the same the middle is been the opposite direction and it could potentially break the motor if stressed for long period of time

And now use the Lego Buggy motors

Just a quick note, assuming 100% efficiency from the motors the absolute maximum horsepower you would get from 8 xl lego dc motors is about 0.043, not 0.1. Realistically your looking at 60% of that, so around 0.02 horsepower

A flywheel approach with larger wheels should work. Your main problem is that the wheels are too small, causing the car to spin out of control at a certain speed. A flywheel could potentially be enough force to run the larger wheels at high speeds.

For the last car, probably build a chassis that doesn't have so much flex to it.

5:53 Hope Richard Hammond doesn't watch this. 🤣

the grey version of the pullback motors you used seems to be geared for 43mm tyres while the black version seems to be geared for 30 mm ones.

Tip:: when attaching anything with an lcd screen onto one of my RC vehicles/creations, or using it "in the field" for this sort of experimenting, the moment i get the monitor/sensor, or whatever it is that has a shiny screen, is I first peel off transparent packing tape from a roll, cut to fit, and apply it to the shiny new screen. Sometimes i wont even cut to fit, because i know ill be replacing that packing tape "screen protector" sometime soon. Thought this *may* be helpful... with future speed monitors or whatever else... that has a nice new shiny screen someone wants to protect

I build some Lego RC Cars with BL Motor too. And i can beat the 50 km/h without bearings and with only 2S Lipo Batt(7,4V). I lubricate the moving parts whits Glycerine. This will work fine. If you want to drive on raff roads, you have to add a suspension on the car. This will make it a lot more stable if you have not a plane ground. A steering Gyro ist also very helpful at high speed. You can reach 70 an more Km/h with the BL Motor you use in the Vid. Im sure.

Hi James, big fan of the channel. Here's an idea for something that seems to be right up your street in terms of techniques. Why not try making an RC plane which has an EDF/Prop for low speed flying and a rocket for high speed flying. I know you've got something like this in the past but the new twist I thought you could put on it would be to take inspiration of some military air craft (like the F111 and the F-14) which have a variable wing geometry design commonly called swing wing. This way you can have the wings out for low speed take off and landing and then sweep them back in flight for a really highspeed rocket assisted run.

All the cars shown in this should be kept to separate classes for their respective records. (Lego parts only, modified - non wheel driven, modified - wheel driven.)

"Only rule is car has to be ou t of Lego" proceeds to use RC car/jet propulsion

bro never thought of combining the three 💀💀💀💀💀

If you add suspension the last car will survive much longer

5:00 Holdup, you can 3D print LEGO bricks?

You need to look into some actual lego building techniques to make the things you make stronger. Instead of just placing beams directly on top of each other, if you place two single plates between them, the holes will line up at exactly the right distance so you can add vertical beams connected with pegs. This will make a much stronger structure.

you know Legoland glue the bricks together with superglue, so you have a pass to do that also.

"and 2, the cars are made out of Lego." Oh, so this is basically rally Group B, but Lego. 😳😳😳

that should have been rear-mounted steering: more roll control

U CAN ADD LARGE LEGO WHEELS INSTEAD OF SMALL

For rocket engine you should have used spoiler in both front and back end to increase traction. It would have easily broke your record.

BTW dark ice designs do make metal axles

This is a really sweet video. I"m an adult fan of LEGO and must be very naive for I was hoping for faster speeds. I must say, you have incridible determination. I loved the model rocket engines on the cars. They really reminded me of the long, slender, rocket powered LSR-type of car. Thank you for this video and best wishes.

"feel a bit silly playing with lego in public" That cracked me up :D interesting content tho especially for kids or beginers interested in engineering. Or someone going down a youtube rabithole at 4am on a 'school night' :)

if you put the rocket engine in the front of the car it wouldnt fly that easily of the track

really cool video!!! i too love experimenting with all kinds of r.c. motors/parts of all kinds.

There are Lego parts you can purchase like axles and beams that are made of metals like aluminum/aluminium, they’re a lot stronger and can withstand higher RPMs for much longer

I guess making the car wider can improve stability. Rocket engine are best accelerating engines

could you release an edited version where every time the lego car crashes you get the lego star wars breaking sound effect

Oh really cool done, you can do so much with LEGO

Did you try to power 8 XL motors with a single Lego battery pack? Voltage drop on that would've likely been insane and I wouldn't be surprised if it would've been faster with less motors connected to it.

Cool it’s awesome to see the cool projects you make

Many years ago my friend wired up a couple of model rocket engines to the 3rd stage of the speed stroller on his Tamiya King Cab. On engagement of full power, the rockets ignited, propelling the car at massive speed before hitting a kerb and flipping.

Maybe you could build a train instead. So the vehicle won't need to carry batteries and would be more stabilized. Additionally modify a cable to brifly touch the rails instead of using a train motor so it would be still scalable

You should build a rideable ekranoplan. It's sort of like the hovercraft, but it would still be pretty cool, and a rideable ekranoplan could be a transition to rideable planes.

Yeah so that much Lego motors should definitely go on different battery boxes and different ir recievers BC you were overloading them, and definitely if you want speed or power. And you probably don't know but the different motors have different speeds and powers.

Probably could start bringing a broom along with to get those rocks and pebbles out of the way! They kinda suck when dealing with smaller diameter wheels and tires.

that with the glue, some would say, that´s ilegal, but almost every hobby lego builder is using it for big projects.

Please make a high altitude ground scanning rocket to find important test rockets

If surviving the test was a criteria then the record is still 12 kmh lol

Maybe try doing it on a smooth surface… if you were to take these cars full size it would be like trying to go 160 mph on a off-road circuit

I feel like shock mounting the rocket motor on a linear compression spring would reduce issues, as it would act like a capacitor/inductor smoothing out the high jerk from the motor. Basically it would go faster/further if the motor was mounted on a spring... Maybe?

I bet you could turn that into a track launcher that kills people in about two minutes...