pUs

1992/1993 TRF 411X build from new parts

Recommended Posts

So, I've decided to document this build a little bit. Since a big chunk of this car's DNA is Dyna Storm, I thought it might not be that interesting - I've read several Dyna Storm build reports and you're probably quite familiar with the DS. But even so, the 411X is pretty rare. I tried to get hold of one for more than 20 years without any luck but just recently, I finally got the chance to buy a big batch of unused TRF spare parts. Actually enough new parts to build a whole 411X, except for the front shocks and the spur gear cover (cover exists, but has been used..).

Since there's not that many detailed 411X pics around, I've decided to document at least all the areas of the car which deviates from a 'standard' Dyna Storm. Which is actually quite a lot. The car has a big amount of unique moulded parts which, sadly, were never used in any production Tamiya. The way it goes together does not feel very prototype-like at all, on the contrary it's typical 90's Tamiya, very well thought out and easy to assemble. I think it must have come close to being produced. Particularly the front gearbox has a very clever design and looks a little too refined for "just" a prototype.

I'll start with the front drivetrain and work my way towards the back of the car.

  • Like 4

Share this post


Link to post
Share on other sites

Before starting the build, here is a quick overview of some of the parts which will be used. There's an awful amount of duplicate parts and I really haven't had the time to sort out just the stuff needed for this 411X. Not all parts are intended for the 411X either, if you really know your vintage TRF cars you could probably spot a few other special parts in these boxes ;)

I've received two different types of chassis plates. The one to the right has been used heavily, the one to the left is new and unused. Haven't decided yet which plate to use since the configuration is a bit different - the worn plate is a direct fit with the Parma Tomcat body + Lazer under cowl (which is what the team used in 1993). The new plate looks a bit cooler I think, but only fits with a Top Force body it seems. I did however get several of the new type, so I might just cut down the rear outer edges somewhat..

01_-_parts_s.jpg

  • Like 3

Share this post


Link to post
Share on other sites

Starting with the pulleys. These are moulded parts in the typical white/yellow tamiya plastic, and I'm pretty sure the diff pulley was a totally one-off, to my knowledge it has not been on any other Tamiya car before or since. It looks very much like the Yokomo M2-pitch seen on early Works-91 cars, very fine pitch and also quite narrow in width. The side rings has to be glued onto the pulleys, at least this is obvious for the layshaft belt pulley assembly which doesn't stay in place. Diff pulley is a bit better but I glue it anyway;

02_-_pulleys_s.jpg

I was told that the 411X only had a permanent 4WD to begin with, but I really can't see how this could work with the layshaft I was given (perhaps two types of layshafts did exist). Anyway it's a direct fit with a one-way bearing put into the pulley, so that is what I will use. One-way bearing looks identical to the one found in the Top-Force Evo (haven't measured it though).

03_-_pulleys_glued.jpg

Share this post


Link to post
Share on other sites

Starting with the differentials, I've been told the only difference from a regular, rear Dyna Storm differential should be the front pulley and the front outdrives. Let's hope this is the case ;) There's an obvious offset difference between the front and rear outdrives as you can see below - standard is centered and the 411x front differential sits to the side;

04_-_pulleys_w_outdrives_s.jpg

Edit: Yes, front diff itself went together smoothly, however I probably miss a custom machined aluminium bearing spacer, much like the one used on the Kyosho Lazer ZX-R differentials. It's needed on the longer outdrive to stop the ball bearing from sliding inwards.. probably an aluminium or plastic sleeve. Build paused for now, looking for the right part..

Share this post


Link to post
Share on other sites

Sorry for the delay, build has now continued. Will try to add the rest later today :)

Share this post


Link to post
Share on other sites

Would you be able to share how you came across these parts to build the entire TRF411X and also a little history/info on it? Just curious because my knowledge is very limited in regards to off road car and I would be very interested in learning about another Tamiya race prototype. Thank you for sharing what you have :-).

Share this post


Link to post
Share on other sites

Byteme909, on 28 May 2015 - 7:55 PM, said:

Would you be able to share how you came across these parts to build the entire TRF411X and also a little history/info on it? Just curious because my knowledge is very limited in regards to off road car and I would be very interested in learning about another Tamiya race prototype. Thank you for sharing what you have :-).

Sure :)

The parts have some history. They originally belonged to former Tamiya/TRF driver from Spain, Daniel Vega. Extremely successful driver and also a really nice guy, he won numerous national Spanish titles when driving for Tamiya. He continued racing his TRF cars for several years after Tamiya had quit the development of the 211X and 411X completely. It's not that well known but as a nice piece of trivia, he actually won the 4WD B-main at the 1995 Euros driving the 411X. He came within a tenth or so to qualify for the A-main. Quite impressive, especially considering the more modern cars which were around at that time (YZ-10's, Schumacher Cat 2000 EC's, Predators etc). According to Daniel himself, it wasn't really the car that held him back but rather his batteries which were not on the same level as his competitors. In any case, pretty impressive achievement for a one-man team, being totally alone when setting-up the car.

He kept driving for Tamiya up until 1997 when he finally switched to Yokomo / Associated.

Regarding the car itself, there's really no official info available so I can only try to compile what I've heard directly from Daniel and other drivers who had the car. Unlike the 211X, there was never any "manual" or schematic drawings or anything released - just a bunch of parts. Initial development was done during 1992 - this is very obvious when you study the parts for the 211X (prototype which later became the production Dynastorm). The gearbox and rear bulkhead was from the very beginning designed to support a longer layshaft and an "offset" + reversed position to make room for the drive belt and to mount the motor in the middle of the car. On top of this, several parts for the suspension and front damper mount were already existing on the 211X part trees and were actually shipped with all 211X "kits", even if they weren't used for the 211X's at the time. So the 211X and 411X were sort of created in parallell.

Anyway, the teams in UK and Japan started using the 411X in competition early in 1993. Other European drivers received the car during spring 1993 with some exceptions (Finland got one car for the 1994 Euros, big delay for reasons I can't remember). There were several types of chassis plates used, one which resembled a ZX-R Mk1-chassis and one which had cells further forward and seemed to be made for a Top Force under tray. Also different top plates for different flex characteristics.

There were different front suspension configurations used since the arms and stuff were interchangeable with the Top Force / Manta Ray family of cars. Sometimes using Top Force lower arms and the red steering knuckles. However, the "original" configuration was using the blue TA01/02 "wide" suspension kit steering knuckles together with custom machined suspension arms (around 5-something millimetres wider). I guess this was to both improve steering scrub radius and make the front arms almost as long as the rear ones - the Top Force had quite a big difference. There was a also a long-arm front suspension used by some at the Euros in 1993 which had really long custom machined suspension arms, similar in width to the Lazer and Yokomo. However I don't know if these were coming from Tamiya or if they were UK made (I have these too).

The 411X wasn't really that successful during it's one and only "official" season in 1993. The UK team didn't do that well at the worlds in Basildon, but came very close to making the A-main at the Euros. In any case, it was never released as a kit which I think was not necessarily down to the car not performing - my guess more because of Touring cars growing more than anything else. Touring cars was really Tamiya's main focus for the years after this if you look at the cars they released.

I'll probably try to put together all I know about the car and make a web page or something about it later on :)

  • Like 4

Share this post


Link to post
Share on other sites

So, build now continues. It took a while to find something adequate to hold the bearing in place on the longer diff outdrive. I finally found these remains from a parts tree within the parts I got for the 411X. I have no idea if these are correct or not, but they did work perfectly without any slop or binding;

02_-_sleeves.jpg

Which gave me this result;

01_-_diff_w_flange_1.jpg

Share this post


Link to post
Share on other sites

I thought all was good with the differentials at this point. However, later on I realized that the rear differential has to be built with the same, custom outdrives as the front differential, only flipped left / right. The reason for this is that the whole transmission is not mounted in the center of the car, it's offset roughly 10 mm or something! I knew about the offset all along, but hadn't realized this means you can't use standard Dyna Storm outdrives in the back either... ;)

Luckily I did receive several pairs of the custom outdrives, so I re-built the rear diff with these on. You can clearly see the off-set position of the gearbox below, and the need to use different kind of outdrives L/R:

11_-_transmission_offset.jpg

Share this post


Link to post
Share on other sites

Back then to the rear gear-case.

The layshaft used is a bit weird. I thought it was a TR-15T layshaft, which it looks like, but a few of the flanges and measurements were different. Could be because of the one-way bearing and all that stuff, I don't know really. In any case I could not use the TR15T-shaft and had to use the supplied layshaft;

03_-_layshaft.jpg

Inside the gearbox, things are just like the Dyna Storm, except the fact that you flip the ball bearings so that the shaft can be mounted from the other side around;

04_-_transmission_1.jpg

05_-_transmission_2.jpg

Once assembled, the one-way pulley mounts directly to the side. Tolerances are really tight here, but nothing appears to rub. The gear case has a small, round indent, designed specifically for a 411X pulley..

06_-_transmission_3.jpg

Share this post


Link to post
Share on other sites

The hardware then mounts from the side, much like on the Dyna Storm. The aluminium plate is specific for the 411X, in order to clear the right hand side of the suspension arms and mounts. The fiberglass piece is also unique for this car in order to wrap around the motor and bearing holder.

08_-_transmission_plates.jpg

Belt then pulled over the pulley before mounting the plate;

07_-_transmission_side.jpg

Share this post


Link to post
Share on other sites

On the outside of the gearbox plate goes a flanged bearing, much like the setup on the nitro TR-15T. After the flanged bearing, an E-ring secures everything.

09_-_transmission_flanged_bearing.jpg

This pretty much completes all the "special" stuff in the rear gearbox assembly (slipper clutch is identical to the Dyna Storm).

10_-_transmission_complete.jpg

  • Like 2

Share this post


Link to post
Share on other sites

Now the really exotic stuff begins, the front gearbox :) This is very rare, never appeared on any other Tamiya cars. All parts are moulded, nothing machined from what I can see. The assembly consists of a bottom, a top cover with geared racks inside, an internal lower part (with geared racks on top) and two bearing holders in the shape of gears. From the shape and size of it, I'd say it's very much inspired by the older Yokomo front gearboxes on the "Works" 91-92-93-cars.

12_-_front_transmission_parts.jpg

The point with those geared bearing holders is that the lower geared "rack" plate (top left) is not fixed - it "slides" in the bottom of the gear case (although it sits pretty tight). You can then increase the tension of the drive belt by adjusting the screw which makes the plate slide forwards. The whole diff assembly will then adjust itself and roll on the racks inside the gearbox. A bit weird, but it does seem to work. The diff sits very tight so I guess you had the procedure was to undo the screws for the top part somewhat before attempting to adjust the screw..

I might add that I'm not entirely sure that the screw itself is correct. It looks suspiciously much like a Yokomo diff screw, never saw that "bent" style on any Tamiya screw before. It does fit though, and makes the assembly feel robust.

The differential is mounted like this on the bearing holders;

13_-_front_case_and_diff.jpg

And sits like this in the lower gearbox half:

14_-_case_diff_mounted_1.jpg

Mounted on the chassis plate;

15_-_case_on_chassis.jpg

Much like the case on the rear pulley, it's pretty tight. But the diff spins freely.

The adjustment part might appear a little over-engineered, but the overall concept seems very nice. You can see that there are no mounting points for the wishbones directly on the gearbox assembly, which is a really big improvement over the Top Force. The design is very "modular" since the damper mount also mounts on top of this assembly. If something breaks, it's not very likely to be the gearbox itself. At least that's the impression you get :)

  • Like 3

Share this post


Link to post
Share on other sites

To complete the gearboxes and have them mounted on the chassis, the hardware for mounting the front of the gearbox assembly needs to be completed. It consists of small plastic pieces and aluminium tubes of which one is sadly missing, but I'll have one made later on. Up until then, I'm using a Corally 1:12 battery post as a substitute;

16_-_rear_posts_parts.jpg

Mounted on the car, it looks like this:

17_-_rear_gearbox_mounted.jpg

  • Like 1

Share this post


Link to post
Share on other sites

Once the rear gearbox is now mounted, we can finalize the front gearbox by putting on the top part. Things are pretty tight here and I took care not to overdo anything, which is quite easy when you don't know for sure what kind of screws were intended in all places..

18_-_front_gearbox_top.jpg

Pretty bad image for some reason, but I'll make up for it later :)

  • Like 1

Share this post


Link to post
Share on other sites

I won't spend too much time showing all the small parts for the steering assembly since it mostly uses parts already released in other Tamiya cars. It's basically the "Avante Ball Race Steering set" found as a Hop-up option and of course on the Egress which is mounted on Top-Force aluminium posts. A custom carbon plate then connects the left and right side arms.

I did receive several different steering plates. I thought they were for different steering characteristics and some might be, but the one I mounted for this picture can't be used with regular 411X front arms. It's sticking out too much so has to be for suspension arms bent slightly forward to increase the wheelbase.. I ended up using the carbon plate on the top right;

19_-_steering.jpg

All ball connectors used are aluminium items from the Top-Force Evolution.

  • Like 1

Share this post


Link to post
Share on other sites

So, almost done for today. The assembly for the front damper mount looks like this:

20_-_front_damper_mount.jpg

The plastic piece to the right is "L-"shaped and connects to both the damper mount and to the upper gearbox cover. It feels slightly brittle and prone to breaking when looking at the mount part itself , but the full assembly when mounted feels very rigid. The 411X was almost always being run with short front dampers, probably also a bit Yokomo-inspired at the time..

  • Like 1

Share this post


Link to post
Share on other sites

Final part for today are all the unique suspension parts for the 411X.

Both front and rear suspension arms are machined from a dark blue colored nylon. They have a really nice finish, a bit rough but very cool in my opinion :) Pretty lightweight but still fairly rigid. Rear suspension arm mounts are also machined, and are just big, solid blocks of nylon. Quite a departure from the Dyna Storm mounts which did break occasionally. Another difference from the Dyna Storm is also that because of the transmission offset, the rear suspension mount screws are mounted outside of the suspension pin. I did manage to lay them up the other way around on the picture though..

21_-_suspension.jpg

Mounting of the front lower arms seems very much inspired by the Kyosho Lazer and is a big improvement over the Top Force. The suspension mounting blocks are moulded, and are actually quite soft and seem very durable. Pins are also secured with "E"-rings unlike the Lazer, so the pin itself can't pop out of the suspension mounts during a collision.

That's it for today folks. Sorry about the different sized images etc, I'll probably go through them later and sort them out in better resolution and a bit more standardised format. But not enough time at the moment.. ;) Build continues next week!

  • Like 5

Share this post


Link to post
Share on other sites

It's like a piece of history is coming alive right before our eyes.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now