Building the FASTEST LEGO Car

I built some Lego cars to see which was fastest! Go to brilliant.org/ProjectAir to get a 30-day free trial + the first 200 people will get 20% off their annual subscription.
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DISCLAIMER: This video is purely for entertainment value. Personal use of video content is at your own risk. Recreations of experiments, activities and projects are the sole legal responsibility of the person(s) involved in replicating them. I can not be liable for any information or misinformation, wrongful use, damage to personal property, death or any circumstances that result from replication of any projects seen. Be safe!

[@Project-Air]

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) ☺

[@conanobrien1]

The 95% of world population prefers KM/H. Why would you need to apologize?

[@weld4200]

Hey man ..i love ur videos ...i just want to say 1 thing that jarrd my nerves about this ..U CHEATEDD ...I CANNOT CREATE YOUR OWN LEGO BRICKS ..U HAVE TO USE WHAT LEGGO HAS GIVEN YOU ....ANYBODY IN THE WORLD OF LEGGO KNOWS THIS ....I HEREBY CALL FOR A REDOO.

[@srtgrayfrance]

What you should apologise for is writing kp/h: kilometres per per hour? Come on man, you know better then that! :)

[@pusnirizda5481]

Don't apologize/ mph for a burger-per-sqare-bananas countries. Real humans use km/h.

[@dantevito1193]

​@@conanobrien1 yeah, youtube channels that use only imperial without metric conversions (especially for natively metric measurements) should apologize

[@MarijnRoorda]

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.

[@gv100_blitz]

Can’t see a gym allowing rockets but for wheel drivin testing that’s a good idea

[@dolan-duk]

Maybe a collab with the Brick Technology channel or Half-asleep Chris?

[@stanb1455]

I agree, I was internally screaming about how he was neglecting the suspension, just go kart-like fixed wheels.

[@LucasDynamics]

I would help if help is needed...

[@paulbrouyere1735]

Well, you definitely managed to make me laugh. Is it possible LEGO designed it’s motors for kids in such way that the parents don’t throw the whole kit in the bin after one time use?😂

[@ArsonalTech]

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

[@TheBrick-xi8uh]

seriusly

[@Incorrect._.Political]

Building a rocket out of Lego

[@shaiqbutt7871]

Brick technology definitely knows how to build every type of suspension for a RC car

[@TinyRobotED-tm9rs]

Yeah

[@bojohannesen4352]

Nah. This guy would drag BT down.

[@OfficiallySnek]

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

[@Project-Air]

Good idea!

[@parkerk3599]

Or an EDF fan to cheat

[@XJOKER7000]

Like the McMurtry spuerling

[@prateekpanwar646]

It makes me remember a car from Gran Turismo 4

[@torque-drive2488]

@@prateekpanwar646 chaparral 2j

[@toms2oo8]

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.

[@dehanbadenhorst1398]

I agree

[@dobrent]

Agree, I think he gave up early. Like with the submarine.

[@akira8817]

Also with his fastest rc plane video, he just sticks a rocket on it. The fastest lego car should mean a car made only with lego

[@Ziegeri]

It won't be much faster with just legos, no matter what you do, they are plastic and will melt and or break.

[@oxaile4021]

@@Ziegeri That's the whole point. You have to test and figure out ways to push the limits. This video is like saying you're gonna tune your car for more performance and then just going to a dealer and trading it for a Lamborghini.

[@wind2dk]

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

[@hyperturbotechnomike]

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.

[@AccAkut1987]

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.

[@henrywood5462]

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

[@Project-Air]

There wouldn't be much of a video without them haha, but yes I love showing what hands - on engineering is all about - trial and error!

[@tofu_golem]

The one using LEGO parts entirely was the most impressive.

[@doctorspooger5966]

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.

[@28th_St_Air]

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

[@robedmunds7163]

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.

[@aydinlutmergp4885]

I feel like with the speed of the rocket engine the centrifugal force might be too much but I still wanna see it lol

[@melody3741]

@@aydinlutmergp4885those cars go at 2-4rpm’s on what a 15 foot wide track?

[@themetalslayer2260]

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

[@Lampe2020]

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

[@MODElAIRPLANE100]

Kmh^-1

[@MODElAIRPLANE100]

Kp/h if k means km is acceleration in kmh^-2

[@Lampe2020]

@@MODElAIRPLANE100 I think he meant speed and not acceleration.

[@tschichpich]

imo kph is wrong and only km/h is right. kph would be kilo per hour and missing unit of distance and it infuriates me that the m gets dropped

[@melody_florum]

6 kilo per per hour! The rest of the video uses km/h so I think it was a typo

[@BrixDownUnder]

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

[@guard13007]

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

[@tymumm3744]

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.

[@BenjaminGottsch]

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.

[@mortimersnead5821]

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

[@Jim__bob]

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!

[@JensPilemandOttesen]

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.

[@MCsCreations]

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

[@Lust4Machine]

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

[@boomknight1015]

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.

[@poemes]

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

[@PCrailfan3790]

I kinda find it funny that a guy with little to no experience with Lego try to make the fastest Lego car with low speed-high torque motors.

[@air-headedaviator1805]

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

[@noodlenoggin70]

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.

[@cusscuss2536]

LETS GOO AN UPLOAD

[@swecreations]

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.

[@jakhazardzn9862]

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

[@marcovw6415]

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

[@uavcrazy9562]

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).

[@RobDavisAkaMonk]

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.

[@GeneralPurposeVehicl]

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.

[@englishforkids6109]

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

[@ChevyboySS79]

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

[@alfu3576]

A longer wheelbase would've helped I think. Great video mate!

[@garratt5]

Making the car wider helps with stability as well

[@yakacm]

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.

[@petersimpson5859]

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.

[@albert-janoolhorst8130]

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

[@Leo99929]

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?

[@wolfmusic8737]

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

[@denzzlinga]

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.

[@fastfur1]

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!

[@sebastianlindow6981]

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.

[@SableDrakon]

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

[@MoMadNU]

10:47 Left Bearing Block has already cracked 😂

[@austinchappell613]

Just an idea, try putting rings on the bottom side of the chassis. Then running some fishing string as a guide to keep everything a little more consistent. However it will create drag. Your videos are awesome 🤙🏼.

[@kuzadupa185]

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

[@whoever6458]

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.

[@ernestlaptiev9046]

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.

[@gwc_garage]

You can crank the wind up motor a lot more. I used to have one and I would just turn the wheels back as far as I could by hand and then hold it till I had it on the ground it ended up being decently quick if I remember

[@richardm.newlands2417]

Love that! 😃 Like any rocket vehicle, you need fins.

[@datthikboi5608]

im very versed in using the lego technic system, and would gladly help you improve upon these cars with suspension, more solid framework, etc

[@rosedruid]

Your last crash might have been due to the tire rubber loosening as the forces of their spin pull he tire to a wider diameter than the hub. My Lego tires always got pulled loose by their spin when I’d run them fast.

[@1.618_Murphy]

Brick Technology is proud of you!

[@SteffenHausB]

"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!"

[@loddude5706]

Maybe front mount the rocket motor, firing rearward in the mouth of a car-length augmenter tube (passive venturi?) Questionable stability gains perhaps, but . . . 'Bring on the noise!'. . . & maybe a servoed (flameproof) rudder! : )

[@LPChip]

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.

[@scottedwards1592]

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

[@thenewmodelworkshop5743]

You needed to add a Richard Hammond mini figure (So about 1/2 scale)

[@basberend]

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

[@TimpBizkit]

I'm curious to know the potential of the C rocket motor angled so it pushes the car into the track slightly to stop it squirrelling all over the place.

[@redpug5042]

on the note of using gravity, you could use a collision to transfer a ton of energy from a big, heavy vehicle to a small vehicle which would make it go very fast.

[@chrissugg968]

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.

[@scottthewaterwarrior]

It's really sad how under powered the LEGO motors are. The power/price ratio is probably even worse then the power/weight ratio!

[@Zaro2008]

Records: Spring powered: 6 km/h Electric motor: 12 km/h Rocket powered: 38 km/h Stronger motor: 42 km/gh

[@Ikller-xh7qq]

You should look up the 3 different Lego PF Motors...You switched from a single M-motor right away to several XL-motors...XL-motors have the lowest speed, but highest torgue out of all PF Motors...

[@betamaxblocker]

All of those shoutouts to Craig Breedlove, the Bonneville Salt Flats, etc. made me think that if Lego was designing a Spirit of America set, they would need to contact you for advice. Also, all I could hear during your rocket car tests was the song about the SoA by The Beach Boys...

[@zaysousa1]

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

[@jestertlsodx9897]

Great video. Getting into RC and just looking for interesting projects to occupy my time.

[@Topper.X.Kaushal]

i like ur content a lot. I want to see u try making a perfect rocked lego car like the professional one

[@camdix3250]

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.

[@kaiperdaens7670]

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.

[@dm1i]

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

[@JohnSmith-lm4nn]

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

[@ToninFightsEntropy]

I made a few lego cars that would have survived most of that. Used to battle them head-on, in my house as a kid lol, so naturally they evolved. The trick is overlapping loads of flat pieces. Don't use the chonky bricks where you don't have to, and sandwich the crap out of them with flat bits when you do. Making the cars arrow shaped seemed to help, too. Build like this, and the cars wont break anymore, but you will start to chip and shatter the actual lego pieces instead, because of how rigid they are. I broke a lot of lego lol.

[@LutraLovegood]

Suspension and some strong shapes would have helped a lot too.

[@justinmacdonald6079]

Been watching you since the beginning bro. I'm so surprised you haven't hit 1m subs like I LOVE watching you. I wish I could watch a video every day. Keep it up. Proud of you. You'll hit 1m in no time

[@johnatangarcia1029]

I think its all about the steering if have enought power. Low the ratio or decrease speed of steering for smooth control if you only want a straight run

[@cchangg]

Your tire isn't staying on the ground. Get some suspension figured out will increase control and speed.

[@michelerandall903]

i would love to see a video of you trying to make the fastest land vehicle using rocket and rc engines for each wheel

[@aaronburnett1131]

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

[@Hasslpaff]

I like that you used km/h. but i don´t mind you using mph as long as you write km/h down in the video. And an idea: have you tried to build an airodynamic lego case? it would be havier and it´ll press the car on the ground giving it more traktion.

[@launarlami101aviation]

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

[@pauljs75]

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.)

[@theodoreanderson1311]

back in middle school I gathered as much lego train track as possible and made a sled train thing that had a purely lego mounted CO2 cartridge in it. you would roll it backward into a backstop with a pin that would puncture the CO2. that thing flew. it would go so fast it would derail from the track or once it reached the end, (about 30~ feet of track(it would only take about 4 seconds) and it's wheels touched unstable ground it would just atomize. took a lot of rebuilds but wicked fun.

[@SuperKamoman]

You know Id like to see you make a lego only powered (maybe except on batteries/power supply) car that can beat the life sized Bugatti Chiron that they made that got up to 12MPH/19.3KPH.

[@jxnion4592]

Man,thats not LEGO,thats LET GO

[@christiangunther7216]

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

[@Tyfu39944]

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

[@thinkdifferent01]

Your biggest enemy is the bad street...

[@jonasfermefors]

Good clean fun.. and an indictment of UK road surfaces 😁 I think slightly wider and more layered build would have been stronger and faster.

[@matthewn9110]

What if you purchased a set like the lego technic ford GT? Ik it's a little expensive for experiments like this but it comes with good wheels, independent suspension, steering, and the wheels connect to the lego engine so you could do an rc engine swap on it

[@450gmo]

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

[@ransom8006]

The rocket would work if you set it up like a slot car. Put a "T" at the bottom to keep it from coming off. An example idea would be two bars/cables drawn tight, over a distance. Then a car with a "keel" of sorts, and a whale tail on the bottom of the keel similar to a hydrofoil design. Then all the rockets your heart desires and hope for the best.

[@disgustingapple5216]

He really went the trailmakers more engine more power lol

[@kingebas2873]

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.