42301 Tamiya TRF419x Build Review and Set-up

Tamiya not only invented the 1/10 touring class back in 1991, but they have also been the most successful manufacturer in the IFMAR worl...

Tamiya not only invented the 1/10 touring class back in 1991, but they have also been the most successful manufacturer in the IFMAR world championship series. Over the years they have taken the title 5 times. and this year they hope to achieve their 6th with the new TRF419X. A car that is very different to the TRF419 that it succeeds.

So will the new TRF419X give them that little extra edge to help them to that 6th world championship? Let's take a look!
Why not cut the differential holes so they are equal left and right?
First up is the chassis, it is the same width as the previous TRF419 (85mm). From above the main difference is that the front and rear end sections are a little wider around the suspension blocks to allow for the wider front end and the droop screws.
The chassis plate is 2.15mm thick
The big primary change in the chassis that will affect the handling is that is is now 0.1mm thinner than the previous chassis and it is now 2.15mm thick. This not only will give a little more flex, but it also makes the chassis slightly lighter. The new chassis is 3g lighter at 68.5g.

To Prep or not to Prep?

Normally at this stage you will have to prep the chassis with CA glue, but the instructions are on trend and they do not recommend that you need to do it. I have been slowly moving away from doing this myself over the last few years. I think it seems to ensure the flex feels more consistent, maybe it's just psychosomatic but it seems that most people do not do it any more. All I did was gently go over the edges with some fine sandpaper to ensure it was all smooth.

Excellent screws and they even come with cool stickers
For the build I will be using the excellent Moodyfools titanium screw kit for the TRF419X. There will be a smattering of Tamiya blue aluminium screws to ensure it looks bling. I will also be swapping out the kit included steel ball cups with the fluorine or aluminium alternatives as they are lighter, along with using blue spacers instead of the kit included black ones.
Same bulkheads front and rear, marked A and B for each side
So starting the build we have the bulkheads. These are a new design and they are 1.5mm lower. They are also made from much stronger aluminium than all previous TRF kits. One thing you notice is that the locating pins for mounting the bulkheads have gone.
A clever way to change flex. However fit all 6 for constructing the car
When attaching the bulkheads on the car you will notice that there are 6 screw holes that can fit into the lower bulkheads (Two at the front, four at the rear). This is a clever idea and changing where you place the screws (or grub screws) will change  the flex and that will make a big difference on how the car feels on the track. So this explains why the lower locating pins are now removed from the bulkheads.

With that in mind, to ensure that you have perfectly aligned bulkheads I would suggest you fit screws in all 6 off the holes until you have finished the build. The gap between the main spur gear pulleys and the top deck is quite narrow, and if you have not assembled the car correctly you might notice that it rubs. If you do get this, I would suggest you remove your bulkheads and try again.
Wide and low, but the same chassis fitting
Next up we fit the new lower wider G-Blocks. A few of us TRF racers had noticed how the original TRF419 felt better with a wider front end, so that's why we started running 1D blocks and then ultimately made some 1F blocks. The TRF factory also were on that wavelength and the kit comes with 0.5G blocks for the front of the car.
Its been driving me nuts waiting for this steering post design to appear on the TRF cars
Now it's time to add the steering posts, and whilst I was unimpressed with the fact that they are not anodised in the Tamiya blue, yet I was happy to see that they have adopted the design that they have used on the recent TBEvo VI. There are many tails of woe of TRF racers who ended up damaging the steering posts trying to remove them, not any more thanks to them having a bolt design so you can use your trusty Tamiya wrench to hold it tight and unscrew it from the other size..

As we move onto the motor mount you can see that Tamiya have gone back to a more familiar two piece design, and this one is very similar in concept to some of the other cars out there.
The new mount is light and two piece
The piece is well finished and its streamlined design does ensure that it is very light with the left and right parts having a combined weight of only 12g!  As you can see there is an optional centre post which you can add or remove as a tuning aid.. and as you can see its in black (Hmmpff!).
Floating above the chassis
The motor mount is very narrow with the screws close to the spine of the chassis. As you can see from the picture above a lot of the mount raised from the chassis to ensure that the chassis is able to flex freely,

**Note, you can still fit the older motor mount from the TRF419 onto the chassis, but there are only 3 screw holes on the chassis that mount it so you do loose some of the flex options that it had.
The locating lugs ensure it is a very solid fit
The upper bulkheads have had an interesting development, they are designed so the camber-link mount is able to have it's horizontal position changed with the addition or removal of some shims. This is a very nice feature and it is a tuning option that I have never seen given such fine adjustment on any TC that I have owned before.  For those that are interested, if you add more shims you make the upper camber link shorter which will give you more camber gain as the suspension compresses and the opposite gives you less camber gain. So you can tune how aggressive the car is when cornering.
  • More shims = More aggressive, more turn in and more steering out of the corner
  • Less shims = More stable and easy to drive, less turn in and less steering out of the corner. 
The parts are really good, however again as you can the extension parts are anodised in black. The whole kit has a mixture of black and blue anodised parts and frankly I do not like it. Tamiya Blue is such an iconic colour, I have no idea why Tamiya have done this, so I have tried to use as many blue substitute parts as possible for my car, so I will use blue shims instead of the kit included black alloy ones etc
This differential is very smooth when running
The diffs are the same design as the TRF419 versions, these are very smooth but they could leak, and some people had issues with the shims coning.
Ensure you do not over fill the differential
I built mine with the kit black o-ring as per kit and was keen to see if there were any minor changes that had been made that I didn't notice.
The differential is mounted in the high position to compensate for the lower bulkhead
With the rear differential built it was time to add the rear belt and assemble the bulkhead. The parts attached very well with the fit being perfect. It is interesting to see that the kit instructions recommend you to fit the differentials in the high position. In previous cars the diffs are in the lower position, so it shows that there is a different approach on the base handling for the 419X with the differentials being set high to reduce the roll in the corner.
These Axon spurs are fantastic
The drive pulley is the same 20T unit from the TRF419. The kit comes with a 116t 0.4mod Tamiya spur gear. I swapped it out for the excellent Axon spur which which allows me to get my desired 17.5 blinky FDR.
Solid and smooth
This spins freely on the motor mount with very little lateral movement.
Probably as optimum as it can go?
As we move to the front of the car it's time to assemble the front spool. Tamiya has redesigned it further and as you can see they have made it as minimal as possible. The pulley holder weighs just 4.6g!
Heavy duty spool cups
The spool cups are the same heavy duty units that were introduced on the TRF419. These do not allow you to fit shaft blades. As I run blinky I will substitute them for the TA06 lightweight ones, reducing the weight a little more, and the plastic shaft protectors will help protect the drive train if I clip the boards (ahem!)
No shimming needed, the whole kit fits together so well
The spool is then placed into the front bulkhead, again everything fits perfectly and the quality of machining is really spot on.
Same design as the TRF419 and TA07
The steering assembly is the same as the TRF419. The kit comes with steel ball connectors, whilst excellent and strong, I used the fluorine ones that I had on hand.
Thin and minimal
As you can see the main centre line of the chassis is essentially complete, and looking from above you can see how narrow it is. The bulkheads are now inline with the steering posts making their overall width narrower by 2mm (The same as the TRF418 and TRF417). So this means that Tamiya have broken their naming convention with the TRF419X as usually all TRF's with the same number can use the different lower decks. So be careful if trying to upgrade your TRF419 to some of the new chassis parts.
The bulkheads are more narrow on the TRF419X by 2mm overall
Here you can see the motor mount, the alloy parts are much more light and narrow than the innovative TRF419 version, although the lower screw holes are still the same distance apart at 13mm.
The new narrow top deck.. I always like the shandy one.
Time to add the top deck. It is again made from 2.0mm thick carbon, but has been redesigned to be more narrow overall with a deeper front cut away. This will add a little more flex at the front of the chassis.
The core of the car is finished
The the top deck does run close to the 20t pulleys, so check that they do not rub against it. If they do then you need to either re-assemble your bulkheads to check they are not twisted (Remember to fit all 6 lower screws in each bulkhead when re-assembling).
The new arms have different shock mounting holes
The lower suspension arms look very similar to the arms that were introduced on the TRF418, however there is an important difference. The damper attachment holes are in a different position on these arms.

The front arms have the lower hole more inwards by 1.5mm and the rear hole is a similar distance outward. To make it easy to differentiate between these and the older arms, the new TRF419X arms have an 'A' on the front arms and a 'B' on the rear arms. (The originals do not have any markings on them). The other slight difference is that the material looks a bit shinier but the parts are not any lighter or softer, I have been told that most new carbon plastic parts will have the same look as they have slightly changed the formula for the plastic.

(NOTE - TRF drivers suggest trying the TRF418 arms on the front of the car if you run D blocks or narrower).
White balls? I think I will go back to the black ones
As we assemble the arms you can see that the kit comes with the Ti-coated suspension pins, but the suspension balls are now made from white Delrin plastic instead of the steel ones that we have become used to. I cannot see how these would have any benefit other than making the car a slight amount lighter.

The damper ball connectors are a new part, shorter than the previous hop up options. They are still fluorine coated, and they also now come in the kit. These are screwed onto a grub screw via a 2.5mm hex, and provide a very good fit with the dampers once they are installed.

**Note that there are shims behind the ball connector, remember to compensate with more or less shims when changing the wheelbase to maintain the damper angle to the upper shock towers.
Best driveshafts in the business?
Whilst building up the car, the rear driveshafts are the same 44mm aluminium parts that we have been using for a few years.
Rear hub is stronger and needs less shims
They are mounted into another new part. The rear hubs are different to the previous parts. The ball mount at the top is higher by 2.5mm so there are less shims needed if transferring your setups. The other difference is that the axle hole is 0.5mm further outwards with a smooth side to the hub. The bearings mount a little deeper to compensate for that to keep the rear the same width.
I once went out with a gymnast who was double jointed ;)
The fronts of the car has the excellent double cardans included. These avoid most of the chatter that std universals will have when cornering with a spool. These are the same solid steel design, the only difference is that they are now 46mm in length, to compensate for the wider front end.
There is less movement than on the TRF419
The steering uprights are the same as before, and so unfortunately are the C-Hubs. This design has been with us since the TRF419 (Although technically the TB04 introduced them first). They have not been that popular as they have more slop than the part they replaced, and they are also more delicate.

The TRF419X does now however have a new flange tube to install with the kingpin. This is shorter and it requires a 0.5mm shim to be installed under it. The kingpin itself is also different, and it is the more common taller version that is in most Tamiya onroad kits. When the front end parts are fully assembled, there was not the same amount of movement I was expecting, maybe they have changed the mould, maybe the new flange / kingpin combo has helped.. or maybe it was just wishful thinking. I will find out when I get to run it.
The arms fall freely
The instructions recommend to fit some 0.3mm shims to the suspension pins to remove slop, I actually found them to be a little too large, so I mounted only 1x 0.1mm shim on both arms and there was no slop and the arms moved freely. The front of the car has a solid 0.5G block to match the inner split blocks. Tamiya will be releasing a range of these lower 0.5 blocks.
The rear end 
The rear is the narrow setting that most of us have been running on the TRF419. It comes with 1XA split blocks and the solid 1E block providing you with 3 degrees of toe-in.  This will give you a very stable rear end. I however mounted a 1D block as I prefer this as a starting block for my base set-up.
Lightweight and easy to set up
The stabilisers included are 1.3mm front and 1.2mm rear. The kit comes with a pair of new 1 piece rod stoppers to fit in the new narrow bulkheads. The kit also includes the fluorine coated stabiliser ball connectors.
I used my own high precision stabiliser mounts
The stabilisers are the same parts that we have been using from the TRF418 so no need to get any others if you have bought the other thicknesses.
Black top or blue top?
Right, so time for the dampers, these are new for the TRF419X and they are low profile and they now use 20mm springs as opposed to the 25mm springs that we have become accustomed to.  These new dampers are the same height as many of the other low profile dampers that are on competitors cars. They are a mixture of black and blue parts (Arghh!!!!) but the lower retainers are a standard part so I swapped them with a blue set, and I also had a spare set of the low profile caps so I could swap them out for the black ones.
These shocks are of the same high quality that you would expect from TRF
There are a lot of new parts for these shocks. These include shorter damper cylinders, shorter damper rods, shorter lower cylinder caps. I am glad to say that they are all perfectly machined and they assemble together easily, fit and finish that you expect from TRF.  The result is a very smooth damper, especially when you have been using another brands low profile damper, you really appreciate the high quality and smoothness of these units.
I just included this as I like the picture.. 
I added muchmore 450 oil to the shocks and drilled a 1mm hole in the plastic parts on the shocks to allow me to have 0 rebound.
Low profile towers!
Now we have the shocks it is time to mount them to something. The TRF419X has low profile towers. They are made from 3mm carbon so they are thinner than the previous 3.5mm thick towers. If you look the lower holes are now not countersunk.
You can swap the screws for gub screws for a little more flex
This changes the way in which they are attached to the bulkhead. With the button screws it will be solid, and you can then swap in some step screws and this will give you a little more flex.
Hybrid motor mount
The chassis is nearly finished now, and we come to the new servo mount. Previously it was a solid alloy piece, but now we have a hybrid alloy and carbon part. The carbon section is 3mm thick so it is very sturdy, and the fully assembled part is 2g lighter. It assembles perfectly, and I think it looks great, although the chassis mount points are the same as all of the older cars from the TRF417v5 so you can swap in an alloy part if you want the bling and the extra weight.
50g of weight to add at your digression
Talking of weight the TRF419X comes with some chassis weights that you can attach to get the car to the required weight. There are two 10g weights for the front of the car and a 30g weight that fits along the middle of the car and also acts as a battery stopper.
Floating again
The weights all feature a locating pin and have a screw hole that attaches it to the chassis. As you can see they float a little above the chassis, ensuring the chassis still is able to flex as much as possible.
These new battery holders work great!
Keeping with the floating theme, the TRF419X has a final innovation waiting to be installed. The battery mounts are mounted on top of the chassis and you loop the tape through them. The rear mount is adjustable and you can move it depending on the size of the battery.
Just add tape
They work very well and when combined with the included rubber strip that you tape on the the chassis the battery is very firmly seated.

So we now add the bumper which again is a new part. It sticks out 5mm further forward so it will stop you from needing to add foam to it for most racing shells.. Bigger bumper Yay! The only problem is that the part number in the instructions is for the older bumper that we have been using for years. Hopefully this will be available as a separate part.
So here is the finished car, maybe the Bluest TRF419X out there ;)
I'm pleased how blue I have got this car
The chassis weighs in at 458g without electrics and the titanium screws
Super Blue


So it was time to see if the TRF419X was worth the wait and to see if it would live up to its expectations on the track.

I installed the following electrics onto the car.

  • Muchmore Fleta pro
  • Muchmore Fleta ZX 17.5
  • Sanwa 417
  • Sanwa BLS v2 low profile servo
  • AMB hybrid
  • Turnigy Nanotech Ultimate 7500
The car was perfectly balanced left and right with a 50/50 front and rear distribution. and weighed in a 1254g (Including the 50g Tamiya weights).

Track test

I was racing on a small technical carpet track. The grip was low to medium and the boards were ready to catch me out in case I made a mistake. I mounted a set of Sorex 28 blacks on the car and had a few installation laps with no additive just to check that the car was pointing in the right direction and no screws were going to come loose.

I had forgot to pack most of my 20mm springs so I was limited to some Xray 2.5-2.8 progressive springs and the kit included Tamiya springs. So for the first race I mounted the 2.6 springs.

The car launched away at the starting beep, the lightweight and free drive-train spun into action and the acceleration was fantastic. I had tuned my Muchmore Fleta ZX on a motor analyser (Article soon), and I was really impressed on how quick the car raced down the start straight. This led onto a large sweeper and the front end instantly responded even when I was on full throttle. The car was over-steering massively so I had to ease off the power to keep the rear end in check. I had a little bit of a comfortable gap so I dialled out some of the dual rate and gingerly drove the car around to still take the win.

With the first race under my belt I wanted to calm the car down a little by adding some more grip at the rear. I removed the centre post from the motor mount. I then placed the lower deck screw in the motor mount hole where the centre post was held in with the grub screw.

I also changed the screws in the lower bulkheads. This should change the way in which the centre of the car would flex.

As I placed the car on the carpet for a few warm up laps before the second race I instantly noticed a massive improvement on the rear grip levels. The car was very very stable, almost too stable for me as I do prefer a car to feel reactive. I almost couldn’t lose the rear end even if I tried. As I finished my few warm up laps I lined up and the car was a breeze to drive, very stable and very quick. I was 0.6 seconds faster on my fastest lap! I had no problem with the car and I managed a good gap for the lead in this round.

For the third round I wanted to dial in a bit more steering again without getting rid of the very stable rear end. I decided to use the new feature of the TRF419X and I shimmed out the bulkhead camber link mount points by 0.5mm on the front. A shorter camber link would give me more camber gain on the corners and this would make the car feel more reactive. This was really easy to do and it only took a few minutes track side to do this. I also swapped the springs for the Tamiya parts to see what they would feel like. The seemed a little softer than the 2.6 springs that I would normally use on carpet.

I got to the track as quickly as I could to see how the car felt with the changes and I was pleased to see that the chassis had responded well to the new settings. I could tell with just a couple of practice laps that I had made the car feel more alive again. The rear end was still planted, but the camber gain on the front really helped give the front more turn in and more on power exit steering.

I was feeling confident for the third qualifier and the car did not disappoint. The qualifier itself was a bit more messy that the previous rounds so I didn’t improve on my fastest lap (although I was very close). I was keen on avoiding any incidents and confident enough that I would probably get FTQ that I was just focusing on looking after the car and playing with different lines.

Suddenly, a backmarker who was recovering from an off, accidentally drove into my racing line as I was charging down the straight. The TRF419x ricocheted off the car and walloped into the barrier. After a few rolls it ended up on it’s wheels. Tentatively I pushed the throttle forward and the car moved silently away, I was expecting some damage but the car felt fine and I continued getting to grips with the car for the final few minutes of qualifying.

When back at the bench I inspected the car and I was pleased to see that the larger bumper had done it’s job. The car was perfectly intact and the C-Hubs were all fine with no damage.

So it was time for the final. I decided to make one more change, I shortened the rear turnbuckles again by moving out the rear bulkheads with a 0.5mm shim. The car felt great in the last round, but I was keen to make the rear just a little more free so I could release it when I wanted to speed up the rate in which I would rotate on a couple of the very tight infield sections.

I got a little sidelined as I nattered with guys in the pits and I didn’t have any time to test the new settings on the car as I ran to get to the the podium quickly drove the car to take its pole position on the grid.

The race was set and I was hoping that the TRF419X would have a good start to its racing season. One the beep the car stormed ahead towards the sweeper. As it was the first lap and I was ahead I did take it a bit easy around the corner without exploring how the new settings had affected the handling. However as I took it so easy the second and third place racers were already on my tail as we entered the tight infield section.

Without hesitation I went deeper into the tight 180 corner, I dabbed the brakes and hoped that the rear end was freed-up enough to ensure I could rotate around the apex quick enough to get a good line out. The TRF419X responded perfectly, and I hugged the apex whilst carrying a surprising amount of corner speed, I then powered out and the rear was very stable as the power went down, pushing me ahead. I quickly arrived at the next section which was a tight S bend, the car was incredibly responsive to deal with me taking my preferred line even though the speed at which I approached it meant that I turned a little later than desired (I was surprised my the speed coming out of the other corner).

The car was feeling great and I was buzzing on how good it felt. I managed to gain a good lead and I eased off a little as I was encountering a few back-markers and I didn’t want to jeopardise the win. For the remaining few minutes I just enjoyed how easy the car felt to drive quickly, the corner speed was really impressive, and the car was smooth but still very responsive, despite the set-up that I had installed on it. I crossed the line to take the win with a good lead and a smile on my face.


here is the set-up that I had for the final. There is still a lot more speed to dial out of the car. I need to get the new measurements into RC Crew Chief so I can look at a few other new ideas.


I had high expectations of the TRF419X. Tamiya had taken longer than normal to develop and refine the car before bringing it to the market. The extra time has been worth it and this car is packed with many innovations and refinements over the previous car. I would really say it is more like a TRF420 than a 419 iteration as pretty much every key area of the car is new.

It is not perfect however, the price is quite a bit higher than the TRF419, although it does come with everything you would need to win in the box. The black anodising is very odd, its strange and all of the other Tamiya racers that I know also share the same sentiments where they do not really like it. The C-Hubs are also the same, although I must say they seem to be performing better at the moment, as is the diff. No leaks at all from the diff.

This car is all about winning, and in reality it is the trophies that we want to look at on our shelves and not the chassis, and its here that the Tamiya TRF419X is already proving itself. The TRF team drivers are performing well at the ETS, and importantly other TRF racers who have this chassis are getting great results at club and national level. This proves that this car is inherently quick and able to deal with a wide range of motor classes and track types.

The other exciting thing about this car is that even though I know it's quick, I can tell there is a lot of speed to be untapped from the chassis and I cant wait to get it back on the track to try to uncover its full potential.

So worth the wait? In my opinion yes :)

Available from your local Tamiya Stockist.  Contact http://www.hobbyco.net/ for more info.
TRF419X 1896058426033950929

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  1. After looking at this with the 418 vs. 419x arm difference. Should I run the 419x arms on my ta07 with the ssbb dampers? Or are the 418 arms fine for it?



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