[MOC] 1:8 Koenigsegg Agera RS

[mihao]

I’m excited to share my latest project: a 1:8 scale LEGO Technic Koenigsegg Agera RS MOC.

 

Functions include:

1. Independent suspension on all wheels for authentic movement
2. Fully functional dihedral synchro-helix doors, trunk, and hood
3. Removable convertible roof
4. Adjustable body height
5. 8-speed gearbox with Drive / Idle / Reverse stick
6. Paddle shifters and working steering wheel (HOG control)

Here is the full demo video on Youtube:

 

Power Functions compatibility:
PF motors can be added to achieve driving, steering, lights, and body height adjustment. In theory, the components can be installed directly; in practice, it’s easier to remove a few pieces first to save your fingers.

Gearbox development:
The gearbox was by far the most challenging component. I wanted it to withstand high torque — tested with two L-motors. Early designs failed due to axle locking during part shifting. After multiple iterations, I refined the mechanism and reinforced the gearstick so it no longer pops back to idle under load. The final result is solid, and you can see it in action in the video.

Dihedral synchro-helix doors:
The doors are a signature feature of the real car, moving outward, forward, and upward at the same time. I achieved this by combining a Technic 28-tooth turntable with a hanging arm — a lifesaver solution that enabled smooth motion across all three directions.

Bodywork:
Designing the large-radius curves of the hood and roof was another headache. After much trial, I turned to Znap elements, which LEGO no longer produces. Despite being unconventional, they achieved a far better curvature than standard Technic or System parts.

Height adjustment:
The adjustable suspension relies on a complex gear train, including mechanisms to prevent over-rotation. Clutch gears are included in both the front and rear systems, so when torque is too high the clutch will slip, protecting the fragile bevel gears (especially the 8-tooth ones).

Instructions:
If you have an iPhone or iPad, the full instructions are available for free via the app: https://apps.apple.com/us/app/agera-rs/id6751605748 (or search “Agera RS” in the App Store).

For convenience, the app includes a missing parts tracker and can generate an XML file for BrickLink orders.
⚠️ Note: Two panels (4446 and 4443 – Technic Panel Curved #54 Left/Right) are not available in red from LEGO. Options include painting them or sourcing from third parties.

I’d love to hear your thoughts on both the design and the instruction app, so I know where improvements can be made. Thanks for checking it out!

[2GodBDGlory]

Looks nice! It's impressive to see a vehicle that can drive at reasonable speeds, while still having an 8-speed on board! Also, it's fun to see Znap usage like that!

[SNIPE]

I wish  I could build this on windows or android

[mihao]

13 hours ago, 2GodBDGlory said:

Looks nice! It's impressive to see a vehicle that can drive at reasonable speeds, while still having an 8-speed on board! Also, it's fun to see Znap usage like that!

When driving with RC, I use the reverse gear, because there are way less gears engaged on the drivetrain. Just flip the direction on the controller. Sure I can still drive using low gear shift for forward, but it is very slow.

 

13 hours ago, SNIPE said:

I wish  I could build this on windows or android

Plan to do it on google store.

[LEGO Train 12 Volts]

Nice supercar

Thanks for sharing the video!

[JesseNight]

The car looks great!
I'm having a bit mixed feelings about the instructions app, but that is my personal opinion. I can see it appeal to a younger audience, I just prefer flat 2D instructions with a bit of challenge anytime.

[Aleh]

Like the original Koenigsegg door mechnism was impemented here!
And I see that the engine is connected directly to the running motors and not to the gearbox. For my tiny opinion with zero exp in supercars it would be more realistic to escape engine running the same speed independently of the gear..

Edited September 4 by Aleh

[jensrodi]

1 hour ago, JesseNight said:

The car looks great!
I'm having a bit mixed feelings about the instructions app, but that is my personal opinion. I can see it appeal to a younger audience, I just prefer flat 2D instructions with a bit of challenge anytime.

My thoughts exactly. Great looking model, I probably have most parts to build it but not with this kind of instructions. I'd go mad going though animated instruction that show one part per step.

[mihao]

On 9/3/2025 at 1:07 PM, LEGO Train 12 Volts said:

Nice supercar

Thanks for sharing the video!

Thanks!

 

21 hours ago, Aleh said:

Like the original Koenigsegg door mechnism was impemented here!
And I see that the engine is connected directly to the running motors and not to the gearbox. For my tiny opinion with zero exp in supercars it would be more realistic to escape engine running the same speed independently of the gear..

Actually, the engine is always running as the same speed regardless the stick position and the gear selection of the paddle shifter. The video maybe not clear enough to indicate that.

20 hours ago, jensrodi said:

My thoughts exactly. Great looking model, I probably have most parts to build it but not with this kind of instructions. I'd go mad going though animated instruction that show one part per step.

22 hours ago, JesseNight said:

The car looks great!
I'm having a bit mixed feelings about the instructions app, but that is my personal opinion. I can see it appeal to a younger audience, I just prefer flat 2D instructions with a bit of challenge anytime.

Thanks a lot for the comments! I expected mixed reactions when I started working on this app, since it’s quite different from traditional PDF instructions.

I completely understand that many builders prefer the “classic” style of flat 2D steps. There’s a certain rhythm to flipping through pages, scanning the layout, and working things out yourself—that’s part of the building habit, and even part of the fun.

My main goal, though, was to make instructions more practical on mobile devices. When I build official LEGO sets from my own parts using the LEGO Builder app on my phone, I’ve noticed that for larger models—especially supercars—PDF scans can be a hassle. I constantly have to zoom in just to see exactly where pieces go.

With this animated approach, the app can automatically focus on the building area, which takes away much of that effort. In fact, the official LEGO Builder app already uses a similar method for many of their sets.

[JesseNight]

2 hours ago, mihao said:

My main goal, though, was to make instructions more practical on mobile devices. When I build official LEGO sets from my own parts using the LEGO Builder app on my phone, I’ve noticed that for larger models—especially supercars—PDF scans can be a hassle. I constantly have to zoom in just to see exactly where pieces go.

With this animated approach, the app can automatically focus on the building area, which takes away much of that effort. In fact, the official LEGO Builder app already uses a similar method for many of their sets.

I understand the hassle with PDFs. In truth I remain a big fan of old fashioned paper instructions, but at least a PDF can be zoomed in when the need arises and that's an advantage.
The animations... can be a bit disorienting to me. Or maybe that's just because I'm not used to it.

(I don't suppose you will release PDF instructions for this?)

[Aleh]

3 hours ago, mihao said:

Actually, the engine is always running as the same speed regardless the stick position and the gear selection of the paddle shifter. The video maybe not clear enough to indicate that.

That's what I'm talking about. Engine should change it's speed regardless the chosen gear, no? I'm confused a bit, sorry :)

No - the same engine speed for different gears reflects the real technology.

[mihao]

2 hours ago, Aleh said:

That's what I'm talking about. Engine should change it's speed regardless the chosen gear, no? I'm confused a bit, sorry :)

No - the same engine speed for different gears reflects the real technology.

Here is what I learned from ChatGPT, if it is not accurate, someone here can help to correct:
 

LEGO setup:

1. Connect the pistons to the PF motor (before the gearbox)

   • Crankshaft spins whenever the motor runs.

   • Pistons move at “engine speed.”

   • Gearbox then reduces or increases torque to the wheels independently.

   • ✅ This is realistic, like a real engine.

2. Connect the pistons after the gearbox (to the wheels)

   • Pistons speed now depends on wheel speed.

   • Upshifting would suddenly slow down piston movement, which looks weird.

   • Wheel load or stop also affects piston movement — not realistic.

---

Conclusion:

Always connect the dummy pistons to the PF motor shaft BEFORE the gearbox.

• Gearbox changes wheel speed independently.

• Pistons move consistently with motor (engine) speed.

• If your PF motor is just on/off, pistons will move at one speed whenever the motor runs — which is fine for LEGO visual purposes.

[Aleh]

@mihao looks realistic, thank you for the explanation!

[Sokolov Edward]

On 9/2/2025 at 9:41 PM, mihao said:

I’d love to hear your thoughts on both the design and the instruction app, so I know where improvements can be made. Thanks for checking it out!

Interesting model. Why don't you post this model with parts list and instructions on rebrickable.com in your account?

Some manufacturers in the instructions make the already assembled part of the model one color in pastel tones, and draw the added parts in color.

Edited September 6 by Sokolov Edward

[mihao]

6 hours ago, Sokolov Edward said:

Interesting model. Why don't you post this model with parts list and instructions on rebrickable.com in your account?

Some manufacturers in the instructions make the already assembled part of the model one color in pastel tones, and draw the added parts in color.

I tried to post on Rebrickable, but they disabled it because the instruction app doesn't follow their guideline. Yes, that is a good idea to highlight the current part. I will consider to use it. For now, I added glowing outline to parts of the current step to make them stand out. Thanks!

Edited September 6 by mihao

[Sokolov Edward]

On 9/6/2025 at 11:47 PM, mihao said:

I will consider to use it. For now, I added glowing outline to parts of the current step to make them stand out. Thanks!

Unfortunately, this design of instructions also has a drawback. Technics designs often use brightly colored beacon parts to make it easier to find a place on the model using the picture in the instructions. Showing the assembled part of the model in one color resets such beacon parts, and also does not allow you to see how the assembled part of the model should actually look in real colors.

Your method of dynamic video instructions is also not ideal. It is even more difficult to determine the necessary place on the model using a moving angle than using a picture in PDF. In classic instructions, hard-to-reach places are shown with additional inserts from different angles. A close-up allows you to examine the necessary part of the model in detail, but makes it difficult to determine the location of this part on a large model.

There is an author on rebrickable.com who makes instructions in 3d pdf format https://rebrickable.com/mocs/MOC-170673/marthart/kenworth-w-900-new-version/#details. The lack of mass popularity of this format hints at its necessity.

Edited September 8 by Sokolov Edward

[mihao]

20 hours ago, Sokolov Edward said:

Unfortunately, this design of instructions also has a drawback. Technics designs often use brightly colored beacon parts to make it easier to find a place on the model using the picture in the instructions. Showing the assembled part of the model in one color resets such beacon parts, and also does not allow you to see how the assembled part of the model should actually look in real colors.

Your method of dynamic video instructions is also not ideal. It is even more difficult to determine the necessary place on the model using a moving angle than using a picture in PDF. In classic instructions, hard-to-reach places are shown with additional inserts from different angles. A close-up allows you to examine the necessary part of the model in detail, but makes it difficult to determine the location of this part on a large model.

It's a good idea to use beacon parts to differentiate the current step from existing model, and I need to leverage this in my next design.

Showing assembled model in one color has its privilege in PDF, because user can only rely on the current angle to decide the location, this also applies to the additional insert. But with the ability to rotate the model on screen, I believe that any uncleared position can be clarified by looking at the model from different angles.

I didn't make the close-up feature at the beginning, back then, user always see the whole model at each step initially. But I soon realized that on a small screen, it is so hard to tell the position of new step parts when the model gets big. I have to manually zoom in to see the new step clearly again and again. (This also happened when I followed the official LEGO builder app to build the Mclaren P1.)  So I decided to automatically zoom-in to the step in a closer distance. My assumption is that, if the user follows the instruction step by step, a close-up view should not be too confusing, after all the user knows what the current model looks like. In case that the location gets lost, a manual zoom-out (plus rotation) can solve it. Anyway, it is a trade off for small screen, maybe I should introduce a setting to control auto close-up or not. Good comment.

 

[JesseNight]

Would it be a realistic option in such an app to make the auto zooming/rotating/animating optional, so the user can turn it off to their preference?

[mihao]

6 hours ago, JesseNight said:

Would it be a realistic option in such an app to make the auto zooming/rotating/animating optional, so the user can turn it off to their preference?

Yes, I am thinking about that too.

[mihao]

I’m trying to bring the instruction App to Google Play (Android). But Google requires that my app is tested by at least 12 people before I can make it public, so I need some help from you here.

If you’d like to support me:

1. Share your Google (Gmail) email address with me via IM.
2. I’ll send you an invite link.
3. You just install the app through the Google Play internal testing link.

Thanks so much for your support.

[Sokolov Edward]

Before importing the partlist.xml file on the rebrickable, replace the part number 2739 with 2739a in it to avoid an error when loading into the custom list.

Request to the author and all other authors of the MOC - do not use prehistoric parts in your models that only you have. In this case, there are insurmountable problems with parts 32212 and 32230. Part 32230 looks great on the body of the model, but it is simply not available for purchase - it was produced in the last millennium for 2 years and only in 3 Lego sets. The Chinese do not produce it. Please come up with an adequate replacement for something more affordable.

[2GodBDGlory]

1 hour ago, Sokolov Edward said:

Before importing the partlist.xml file on the rebrickable, replace the part number 2739 with 2739a in it to avoid an error when loading into the custom list.

Request to the author and all other authors of the MOC - do not use prehistoric parts in your models that only you have. In this case, there are insurmountable problems with parts 32212 and 32230. Part 32230 looks great on the body of the model, but it is simply not available for purchase - it was produced in the last millennium for 2 years and only in 3 Lego sets. The Chinese do not produce it. Please come up with an adequate replacement for something more affordable.

Well, it's true that those parts are rare, but they're certainly not expensive on Bricklink. I suppose that might not work in some locations, but for most builders I don't think they would be too inconvenient to get

[Sokolov Edward]

1 hour ago, 2GodBDGlory said:

Well, it's true that those parts are rare, but they're certainly not expensive on Bricklink. I suppose that might not work in some locations, but for most builders I don't think they would be too inconvenient to get

It's not about the price. I can't access this site from Russia. This part is not available on local similar sites. It's not available on AliExpress either. I don't want to buy rare parts just to assemble one model that won't fit on the shelf.

[2GodBDGlory]

3 hours ago, Sokolov Edward said:

It's not about the price. I can't access this site from Russia. This part is not available on local similar sites. It's not available on AliExpress either. I don't want to buy rare parts just to assemble one model that won't fit on the shelf.

That's what I was wondering, which is definitely unfortunate. I guess what I'm trying to say is that probably at least 98% of builders on here do have access to Bricklink, and so for most builders it's not too unreasonable of an ask. It definitely does make it harder for people to build out of their parts on hand, but in this case there were limited options, and the builder thought using rare parts was worth it.

Could you look into 3D printing a copy of those parts? That's probably what I would do if I wanted to try building this

[Sokolov Edward]

In the original, this part of the roof has the shape of half an oval, not a semicircle. So the options for replacing these parts will be relevant.

https://www.the-blueprints.com/vectordrawings/show/21384/koenigsegg_agera_rs

 

Edited September 16 by Sokolov Edward