In this post, we take a look at the latest in the Ultimate Car Concept Series, 42172 LEGO Technic McLaren P1. We unbox this set, and then examine the first part of the build experience. Along the way, we make some mistakes. How can you prevent making them yourself?

Ever since the very early days of LEGO Technic (Or ‘…sets for expert builders’), there has been a ‘working’ car chassis, bringing us an understanding of how the mechanical aspects of a car might work. Features such as functional steering, gears, pumping cylinders, suspension and a differential. I suspect most of my understanding of how cars work might date back to the early 80s when I first assembled the 8860 Car chassis, and having my Dad and Grandpa explain what was going on over Christmas dinner. It was some time before I attempted to put together a Technic set with greater complexity.

These functional cars have continued to be a feature of the Technic range for over 45 years. The concept received a leg up in 2016 with the introduction of the 42056 Porsche 911 GT3 RS. This marked the beginning of what is now referred to as the LEGO Technic Ultimate Car Concept Series. After tackling marques from the likes of Bugatti, Lamborghini, and Ferrari, the latest set, 42172 McLaren P1, is the fifth in this series.

And I am getting underway with the construction right now. This is my first experience with one of these vehicles. There are many of you out there who have put these sets together before, and I called out for advice on how to approach this the other day and responses had a very consistent theme… “Take Your Time” “Don’t Rush” and “Make sure you get it right!”

Of course, the 24-hour news cycle is as relentless in the world of LEGO Fandom as it is in the rest of the world. And I have a full-time job that sometimes interferes with the LEGO construction. So, some compromises might have been made. And so were mistakes.

My review will be presented in a couple of instalments. In this post, we will cover the packaging and the build experience for the first part of the chassis. (Box 1) The rest of the review will follow in a week or so as, frankly, I need to finish building the thing. We will look at how the instructions and building experience have improved and how I went about troubleshooting some of the errors I made along the way.

Next time, I will finish the build and give you my thoughts on the experience. There is no doubt that spending $AUD699.99 on a LEGO set is a significant investment, and I am sure there are those of you out there who are wondering if this is the kind of set you were looking to get involved with. I am writing from the point of view of someone who has put together a lot of LEGO bricks over the years but has not tackled a major Technic project for some time.

In the meantime, go and pour a cup of coffee, pull up a seat, and read on… Or you can skip over the detailed builder’s journey and skip straight to the halftime report here

Unboxing

The LEGO® Ultimate Car Concept Series is about more than the bricks.

In the press material for this set, we were given a little introduction to the Ultimate Car Concept Series:

The LEGO Technic Ultimate Car Concept Series launched in 2016 and every other year the concept brings a special vehicle to life, where both the set itself as well as packaging has been meticulously designed. Going on the design journey of creating the next Ultimate car challenges the team to design spectacular 1:8 scale sports car models and push the limits of what’s possible. The team aims to continuously prove that with LEGO Technic it’s possible to ‘Build for Real’

My first impressions.

The set arrived in its own packing box, with a couple of one-inch cardboard spacers at each end. After an awkward experience with a small gift with purchase sent out alone in a large box earlier in the year, due to this careful, set-specific packing, if you purchase this set on release day, you might receive the P1 logo gift with purchase in a separate box.

The set is in a large box, with a dark blue and black patterned lid, covering the top and all four sides of the box..

On the top/front, there is a picture of the tail of a P1 from the rear, tail lights glowing – printed with a glossier ink than the rest of the car. Above the car is a dark P1 logo, also printed in glossy ink. From a distance, it appears black. As you get closer, it becomes apparent that there is a mixture of Technic gears, barely illuminated, within the fine white outline. There is a divide between the black and blue weave – darker in the upper left corner and becoming brighter towards the middle of the field. The lower right side of the box is black – broken only by the outline of the bright yellowish-orange car and the rear grille.

Beneath the car are both the LEGO Technic and McLaren Automotive logos.

The printing on the sides of the lid is not designed to be continuous with the top but does continue the black and blue weave pattern. The aspect above the P1 logo has a 1:1 photo of the model’s wheel and tyre. Both short sides have the LEGO Technic|McLaren logos, and the bottom edge of the lid features the details of the manufacturer and patents and encourages you to look at the LEGO Build App to aid you in your construction of the build.

The bottom aspect of the main box, held in place with some sticky tape-type seals, features a picture of the model against a black background—listing the model number, part count, and age recommendation. Unlike other 18+ technic sets, this information is printed over a dark blue and black carbon fibre weave pattern. While examining this side of the box, I cut the seals and lifted the lid.

Lifting the lid

I thought that by this stage, I would have finished describing the box’s lid. I was wrong. On the interior surface of the lid of the box we find signatures of both the LEGO Technic team involved with the project on one side, and some of the original McLaren design team’s signatures on the other. Glossy black on black was hard to read at first, but improves by adjusting the light.

The internal box features a flame yellowish orange/black weave pattern, as seen on the terror in blue and black. Looking into the box, we see a gatefold, left overlapping right. On first look, we see a top-down view of the roof of a McLaren P1.

Opening the left lid reveals the rest of the right lid and printing on the top of the leftmost box. The right lid has the front end of the production car, while the middle third shows the internals of the model, including the chairs and engine.

Once both lids are open, a top-down view of the Technic model is revealed across 3 boxes. The gatefold reveals dynamic pictures of both the model and production car.

The centre box has a couple of punch-outs, allowing you to lift the centre inner box. I removed the outer boxes and kept them in order – the small edge of these boxes I are numbered… 2,1,3. The opposite side has a 3 part image of the rear of the model.

Looking at the main box, we see McLaren chassis number 376 embossed on the inside. In the bottom of the box, we finally find the manuals. There are two manuals. Clearly numbered, #1 has a dark blue and black weave background and a picture of the front end of the production car, while book 2 features the orange/black weave and the tail end of the production car. When we lift the manuals, equivalent images of the Technic model are revealed.

Of interest, the main box can be collapsed by simply flicking a couple of tabs on its sides.

The three boxes open from the side. Each is about the size of a shoebox. Box one contains bags numbered 1-10, along with a soft plastic bag containing a few additional pieces. In my set, all of the numbered bags were paper, some including smaller ‘pillow bags’ containing smaller parts. Box two includes another 8 numbered bags and a plastic back containing larger frames, wheel arches, and suspension wishbones. The final box contains bags 19-23, one soft plastic bag, some flex rods, and four loose tyres. The wheel hubs are included, mounted on a card designed to sit on top of the stacked bags here.

The Manuals

The manuals are thick – the first slightly more than the second. they total 800 pages between them, but this includes 40 odd pages of set photography, tales from designers at LEGO and McLaren, as well as the occasional advertisement for recycling your paper bags and using the LEGO Builder app. Not to mention the LEGO Technic Podcast featuring the LEGO Technic design team, the original McLaren design team, and their test driver. (This was not yet available as I wrote this) Inside the very back pages of book 2 is a link for product feedback and another pointing you towards a special LEGO Insiders page, which needs the number printed on a special tile included in the set. Unfortunately, the link was not live at the time of writing. There is, of course, the obligatory inventory in the back of the book. Fun fact: over 1450 connector pins of different shapes and sizes are incorporated in this build.

It says something about the product that inside the cover for book one, we find out who is responsible for the graphic design, packaging concepts, and photos included in the manuals and the set in general. As the father of a recent design school graduate, it brought me joy to see their names printed in the manual. These are the people who make this set the premium product it is.

I don’t want to introduce too many spoilers for this material at this stage, but suffice to say that each of the McLaren designers admitted to having put together 8860 in their youth. Unfortunately, this might be where we, personally, run out of common ground.

The manual marks each phase of construction, including the component under construction, a brief description of what makes it unique, and a photo of that specific component. It also includes a stylised image of the parts boxes to highlight the location of the parts. I’ll use these headings as I work through the build.

The Building Experience team have gone above and beyond to help us to locate points in the instructions where we might make a mistake in the build, and highlight the correction options:

Where there are similar looking elements included within a bag, the instructions will point out ‘use this, not that’

As we progress, some steps are considered critical points by the Building Instructions/Building Experience teams—these are highlighted with an orange and white rectangle around the area of interest.

The build itself reaches an even 1000 steps. I wonder how many of those steps I will need to retread along the way?

In short, the packaging for this set has a premium feel to it – which is important. this is one of the things that distinguishes this build from other large Technic builds such as the Rough Terrain Crane or Bucket Wheel Excavator. The designers have had great fun demonstrating the transitions from real car to the model and back at just about every opportunity.

There are little touches in the packaging that you don’t expect – the design team’s signatures; the gatefold on the boxes, the covers of the manuals joining perfectly together. They all work to make preparing to build this set an experience in itself. I got a little burst of joy with every aspect of the unboxing. I felt psyched up and ready to embark upon the build.

The Build: Box 1

I suppose I need to start somewhere. As we progress along the build, the Knoller-in-Chief will lay out the elements for us to see.

1/ Exhaust and Rear Suspension

Bags 1-3 Steps 1-133

So many elements in this set are relatively unfamiliar to me. This differential is completely new to me. And an early trap for young players. More on that later. Of note are the foil-rolled golden cheese wedges and quarter-circle tiles. I was also impressed by the variety of colours present as we moved into bags 4&5. I was, at this point somewhat baffled by just how the gears that did not grip onto the internal axle might function in the model. I am told that the elements used to change the gears (upper right corner) – a combination of 2 orange drums and four other widgets that defy description – are new moulds this year. There is also an unmarked plastic bag in the box, which contains some wishbone and spring elements, as well as a few frames.

We start working on the rear axle and suspension assembly. We build in the differential, and troubles begin: substep 4 of step 4, in fact.

In this step, we construct the differential, but in my first attempt, it did not run as smoothly as I expected it to. It needed a significant amount of force to turn. I pulled it apart and found the gear on the open end was not properly centred. I pulled the assembly apart and tried again. This time, it ran smoothly. Prior to building 8860, I had never heard of a differential. would this have ever happened had I not approached that set, followed by Grandpa telling me about its role: to allow the inner and outer wheels to turn at different speeds while travelling around a curve.

I might have tolerated the stiffness I encountered while it was poorly aligned, but I think I might have run into trouble later on.

*Handy Hint for Newbies #1: Axles and gears should turn easily – check them frequently.

We build up the rear frames around the differential and add the first A-frame wishbones. This is where I made my next mistake: installing these frames upside down. The Building Experience team predicted this, making a point of highlighting the small cups on the ends of the wishbones with the orange and white circles. I’ll have to admit, these elements would be better explored if the instructions were available in true digital 3D form rather than using the same isometric projection throughout the build.

*Handy hint#2: when you are invited to pay close attention to what you are doing, please do it!

We added the suspension springs and the universal joints that turn the axles that drive the wheel hubs. As we added the wheel hubs, I came to understand the purpose of these wishbones. They clip onto ball joints on the wheel hubs, forming a parallelogram that moves up and down easily. The plunger spring element attached to this assembly helps it maintain shape.

Before long, I hit another snag (rapidly rectified) with a new (to me) element: The beams with holes alternating at 90º to each other are another piece to be approached with caution. I attached one beam rotated at 90º along the axis to that intended, resulting in a failure to fit.

*Handy Hint #3: treat these beams with alternating directions of holes with respect. They are incredibly useful but seem to be trying to trip me up at every opportunity.

Having successfully navigated these hiccups, we reach the end of bag 1, with the rear suspension and wheel mounts.

In bag two, we expand the space around the rear assembly and build out towards the exhaust. the exhaust pipe is brick-built. We add a drive shaft that moves forward along the base of the model.

As we approach the end of this bag, we have a brief reprieve from the axles and rivets while attach some plates adorned with golden wedges and tiles, emulating the optional gold foil designed to reflect the heat from the engine bay. At least I understand these.

We have also installed a worm gear, attached to an external gear – allowing it to be turned. At this point, it doesn’t seem to do too much. The lack of any leftover gear wheels leaves me feeling confident that I haven’t left anything out, and that this incomplete assembly will be addressed later on. That or it was just put there to troll us!

The primary goal of bag 3 seems to be to give this little worm gear a function: it turns an axle, which in turn lifts a rear assembly. – I expect this will adjust the tail wing of the car. When we first connect up the elevating mechanism, the lift arms move upwards and then backwards, but they are not fixed, and could drop forwards if bumped.

We add a couple of parallel bars which serve to keep the top end of that lift arm moving straight up and down.

This brings us to the end of bag three.

2/ 7-Speed gearbox and V8 Engine

Bags 4-7 Steps 134-281

“Be careful with the gearbox. Take your time and get it right!” The advice I heard rings in my ears. I got so close to getting this right the first time. So Close.

We build up successive plates out of beams (those ones with the alternating holes that burned me earlier in the build, and start to add axles, pins and gears.

The clutch gears (free turning) stack onto the axles – allowing these gears to engage in the process, without adding another layer of bricks and axles., thereby contributing to the process.

And, in retrospect, I made a simple mistake in the next step. One that would prevent the gearbox from working properly. It would still work – just badly. The orange pulley-like elements we install in the next step are grooved. There are elements mounted on adjacent axels that engage with the groove and slide back and forward, adjusting clutch gears that, in turn, change the gears.

As we cap off the gear box, these 4 toothed gears ensure that both gear changing dials change in synch with each other

We add an extension frame to the geat box, and add the engine block. There is a small Technic panel with a printed P1 logo, which sits on top of the engine block.

The cylinders are transparent bricks, allowing you to clearly see the pistons pumping up and down. As you can see, there is a green clutch gear present: this has nothing to hold it in place.

Handy Hint #4 If you have a spare stopper, place it in front of the green gear, and test the gear box: I wish I did this here, rather than later. Don’t forget to remove the stopper before you proceed.

Here is the setup I used to test the gear box. I should have tested Early. But instead, I waited until after the next step, which brings the two parts of the build to date together.

I attached a motor to the yellow connector behind the gear box. The other rod was attached to a universal joint which was connected to the gear changing system. A simple 1/8 rotation results in advancing the gears one setting.

I wish I had looked at the engine at this point(after Step 162) rather than wait until after 181, at the end of the bag. When I tested the gear box I discovered a critical error: the gears did not advance sequentially. on examination, I realised I had installed one of the gear changing ‘pulleys’ back to front

Why do that now? Our next step involves uniting the exhaust/rear suspension from section 1 with the engine/gear box section. I have to admit, lining up 12+ rods and holes was more than just a little anxiety-provoking. This was probably the most challenging single step of the build to date.

The remaining steps in this sequence provide elements to secure these two sections together. We add braces, as well as pipes attaching to the top of the engine block

Disaster strikes!

This is where I set out to test the gearbox. And I became suspicious: The gears did not appear to adjust sequentially: despite constant rotation of the shaft to turn the gearbox, the engine ran at a medium pace, stopped, went faster, slower, really fast and so on…The gear changes were NOT smooth. More of a crunch, and I couldn’t reliably change gears without stopping the rotation. They looked like this:

I stopped and took a breath. All is easy with 20:20 hindsight, but I could not think where I had gone wrong at the time. I went back through the building instructions, and most elements that had been installed in the gearbox were pretty unfussed about which direction they were installed—apart from two, back in step 191! I had just completed step 281. Fortunately, the manual highlighted the area where they expected me to make a mistake.

Handy Hint #5: When the manual suggests that you are approaching a pain point in the building process, check, double-check, and check again.

I knew what I had to do. But I didn’t really want to do it. But, rather than redo the better part of an evening’s work, I found that I could remove a few of the supports from the build and a couple of rods in order to correct the gear changer’s placement. Fortunately, the whole minimal deconstruction-reconstruction process took around 30 minutes.

The build now looked like this:

With my gear changing pulley correctly positioned, I was able to sequence through the gears correctly.

Gearbox Demo

I’m not going to lie. At this point, I felt very satisfied at having located the problem and correcting it. All before everyone I asked for help could get back to me. I took a long, hard look at myself and the way I was approaching the build: I decided that I should start following these handy hints I have been writing down.

3/ Hybrid Mode, E-Mode and Interior

Bags 8-10 Steps 282-426

The P1 is exciting as an automobile because it represents one of the first hybrid supercars – having both an electrical motor and an internal combustion engine. The rod that comes out of the front end of the gearbox/engine block has no connection to the rear wheels of the car. This section starts building a gearbox, which allows the wheels to be connected to a small drum just in front of the gearbox. This represents the electric motor. The assembly we work on next allows us to engage the electric motor AND the engine OR engage the electric motor only OR place the vehicle in neutral.

We have already seen the elements for Bag 8 on our previous tray. Here are bags 9 and 10, completing the first box of elements. There are only a couple of gears involved here – in the bottom left. These will go towards constructing the flappy paddle gear selector. The rest of the elements on display will go towards building the front cabin and chassis. There are a couple of small printed beams (2 modules long) as well as a couple of tiles – one gives a registration number and access to a secret area of the LEGO website. I’ll bring more details of this when it is live.

Anyway, back to bag 9, with more beams, a few clutch gears, and a gear-changing mechanism. Now, build on.

Humbled by my experience at the gearbox, I began paying closer attention to completing the instructions accurately, perhaps at the expense of processing my emotional response to the build.

But we start with the Emode/Hybrid switch. We have switches that act to engage/disengage from clutch gears. In later steps, these switches will become locked so that they move in sync with each other, but for now, it is possible to position them however you like.

We then connect this assembly to the front of the gearbox.It engages with three points in this area: linking the drive shaft to the wheels, the yellow connector representing the engine’s output via the gearbox, and a rod going to the small drum made of several round Technic bricks, representing the electric motor.

The hybrid nature of this vehicle and the ‘E-Mode’ means we use this gear/switch assembly to connect the vehicle’s driveshaft to whichever motor/engine is powering it.

Once we couple the rear of the unit and the hybrid switch assembly, it looks a little like this:

That diagonal yellow rod is connected to the gear-changing system in the gearbox, so I think it is safe to presume that the next thing we will work on in the front of the car will be the flappy-paddle gear changer.

Pulling the left and right paddles forward partially rotates the 8-toothed gear. When the rubber bands are attached, that rotation is completed. This is attached to a 4-toothed gear attached to the gear-changing apparatus.

From here, most of the work to the end of this phase, and also the box, is fairly cosmetic.

We stack a collection of beams together with a couple of panels, and before you know it… comfy chairs. This is one of the big changes over the years since the earliest chassis, which included adjustable seats – the pinnacle of indulgence back in 1981.

We build up the area that will become the dashboard, and in the process, install a beam that serves to link the two hybrid switches. A printed tile and a couple of extra bits help to make up the detail, hiding the frontmost switch in the process.

And now… Breathe.

Halftime report…

We are almost halfway through the build. So, what are my thoughts so far?

This is my first Technic Ultimate Car experience. I have to admit, despite the challenges that the model has thrown at me, I am having a good time so far.

A significant part of the Total Package for this set is indeed the packaging. The unboxing experience is pretty special with this set, discovering all the paper bags full of parts, the wheels and tyres, and the manuals tucked in underneath, to say nothing of the designers’ signatures hidden inside the lid.

The only part of the packaging worth a slight negative point is the fact that the centre part of the lid is supported a little more than the outer edges, resulting in slight scuff marks in transporting, like train tracks down the middle of the box. This is possibly a consequence of the gatefolds on the internal boxes and one that I feel is more than offset by the rest of the unboxing experience. I am sure others will disagree with me.

This type of Technic build is complicated and requires the builder’s full attention. The Building Experience team have done their best to highlight the steps in the instruction manual where a builder is prone to make errors. However, I chose to ignore this in a couple of places at my peril!

It was satisfying to put together the gearbox, but disheartening to see it changing out of sequence. Then, it was extremely satisfying to discover the problem and correct it faster than I expected.

The hybrid/e-mode selector is an interesting feature. I was a little surprised that the sets were not adjustable in any way, as this was a major feature, back in the day! Seeing the flappy-paddle gearbox come together and the way its function was actualised was quite enjoyable.

I will reiterate the handy hints that I have for the casual Technic Builder embarking on a project such as this one:

• *Handy Hint for Newbies #1: Axles and gears should turn easily – check them frequently.
• *Handy hint#2: when you are invited to pay close attention to what you are doing, please do it!
• *Handy Hint #3: treat these beams with alternating directions of holes with respect. They are incredibly useful but seem to be trying to trip me up at every opportunity.
• Handy Hint #4 Test the gearbox at the end of step 260. If you have a spare stopper, place it in front of the green gear. Don’t forget to remove it before proceeding.
• Handy Hint #5: When the manual suggests that you are approaching a pain point in the building process, check, double-check, and check again.

On re-reading these points, I think they can be simplified:

• double-check documented pain points
• ensure the gears/axles continue to turn smoothly as the build proceeds

So far, this feels like a premium building experience – to be savoured, not rushed: rushing is at your own peril. The build is merciless: the design leaves no wiggle room for casual errors. This is one of those places where the maxim ‘Prevention is better than Cure’ holds true. The Instructions designers do their best to ensure a smooth experience – more so than they have in the past – we need to do them the courtesy of heeding their words.

We will be back in a week or so with the rest of the build. Will it be harder? Easier? More Error Prone? How will real life interfere?

What are your thoughts on the model so far? I’d love to hear them. Would you like any questions answered in the closing part of the review? Leave them below.

The LEGO TECHNIC 42172 Mclaren P1 will be released on August 1 2024, and available from LEGO.com, or your local LEGO Store. It will be priced at €449.99 / £389.99 / $449.99 / 589.99 CAD / 699.99 AUD.

You can now read part two of my review here

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Until Next Time,

Play Well!

this set was provided by the LEGO Group. All opinions are my own.