Thunders Racing TA02

[ThunderDragonCy 8970]

Some background: As some of you will know i have got really into racing the Iconic Tamiya class at my local club. I am not interested in the national series, and in the interests of people having fun my club have a relatively relaxed view of what is allowed to race. The adventure started with a TT01E, but as i got better and tried to go quicker i have found it frustrating. I have recently raced both my FF01 and been allowed to race my TB03R, both of which are lovely.

However, being frontie and gear limited the FF01 is already about as quick as i can get it to go around our track. The lads have been very understanding about my very much non-compliant TB03R, but as i am now climbing towards the top three times with this i feel a bit crappy about that. What i was looking for was a compliant, 4wd car which is a cut above the TT01E without getting one of the popular, but very expensive to run, TA04. 

I considered a TA03 with the GT1 rere, but parts are still a little thin on the ground. I also really like the FF01, so i felt the closely related TA02 could be just the job given its regularly rereleased with plenty of spares. Unfortunately this is even more gear limited than the FF01! I asked the guys at the club and those who had raced them said they were nice, but slow. However i think that was more of a national view where tall gearing is everything on bigger tracks. On our track i run around 5.7 FDR, and even my FF01 at 6 is quick and a similarly geared 4wd would be quicker. Then the other week i spotted tucked away on Lord Tony Of Tamiyas 2021 rere post that the TA02 High Speed Gearset is being rere'd. I pre-ordered a set before i had any other plan! Since then Adrian at Racecraft RC has helpfully agreed to split a Calibra DTM kit for me, so a brand new TA02 chassis is on its way. 

According to the gear chart, the 66 spur gives a 6.44 FDR with 25t pinion, but just like the FF01, there is scope on the motor mount to run up to a 28 or possibly a 29 pinion. Whether it will fit in the gearbox is another matter, but i guess some modification might be on the cards. 28 will give me 5.75 FDR which is same as my TT01E and plenty for our track. 

Currently the plan is to fit bearings throughout (natch), keep the rear ball diff, some 2 mill oil in the front fear diff. Tony Tamiya has also been used to supply CC01 universals for the front and an upgrade tamiya prop shaft.

I'll need to take a knife and dremmel to the tub to fit my square lipos (any suggestions most welcome here). 

I don't know much about the suspension setup. I have some lovely 54000 M Chassis dampers on the TT01E, which i will move across. These are wearing the long eyelets from the new TRF V Parts making them 52mm long so hopefully this will work. If not i will sell them and buy some tamiya 55mm dampers. 

The only design thing i have my eye on are 4 deg caster c hubs which i want for my FF01 too. After getting the design wrong with the first lot i have something that should work. I also need to do my own bearing steering. I have tried the 3rd party aluminium kits on a manta ray and they are terrible. I have a set which i have on the FF01, so i will see if there is some like that i can use. 

Other than that, I'll make it up as i go along. And who knows when the gearset will turn up? Might be in time for the indoor season. 

As for a body, i'll use the mondeo for now, but might well do something new for this. 

[djmcnz 755]

My favourite "simple" chassis, keep us posted.

 

[DarkSonic 229]

As for a simple TA02 I would oreintate on the TA02 Racing special chassis kit 58157.

Most of the parts you mentioned are used in this kit. I don't think a FRP Chassis or other fancy parts are really needed in this chassis.

More caster will definitely help. I heard the TG10 parts will fit, but haven't tested it.

Also a very good but rare part will be a stabilizer in the back. 

[nel33 870]

a high speed TA02 gears set, i may or may not need that for the manta. even though the rear gearbox is already built... not sure how it would deal with the 15T motor and 18 pinion but its a hop up parts that be nice to have.

[ThunderDragonCy 8970]

@DarkSonic I will look up the special racing chassis spec. Thanks! Interesting to know the caster is worth a look. I have a 3d printable 4 deg c hub designed already so that is covered. I was wondering about sway bars. I'll look it up. I am sure i could make something myself. 

[djmcnz 755]

I have a NIB Special Racing Chassis - if you need any details just ask. 👍

[ThunderDragonCy 8970]

9 hours ago, djmcnz said:

I have a NIB Special Racing Chassis - if you need any details just ask. 👍

Thanks. I downloaded the manual so i have a pretty good idea. I even have a one way in the spares box i could try in the front. 

[ruebiracer 1325]

Cool project Thunder, regarding your gear options I can tell you, that a 29T pinion is feasable without cutting a hole in the cear case. Did that mod in my 40 years Jägermeister. The trick is, to use the motor itself as a grinding tool with a battery on. So you just take away material, where it is needed and not too much. So it´s still dust tight and bulletproof compared to the method of opening the gear box. I´ll dig out a pic and and will describe how I did it!

[ThunderDragonCy 8970]

@ruebiracer As always, your experience is much appreciated. I actually suspect either 27 or 28 will be the gearing i use. 

[ruebiracer 1325]

I had the same problem and wanted to get a comparable ratio as the TT01 in our class, so came up with the idea, to use the motor pinion itself as a grinding tool.

I set the pinion slightly back compared to the 2 studs of the motor mount, and did it in steps. I think I started with 26t pinion in the holes for mounting an 27t pinion. 

Plug the motor dirctly to a battery and slot it into the gear box. Afterwards removing the small chips. Step by step going bigger with the pinions and changing the mount positions to bigger pinions, too. In the end it looks as in the pic:

[ruebiracer 1325]

I think I´m running 27 currently, too. On a Carson cup machine with a Quicrun 1060. Uses M-chassis dampers and springs for lowering the ground clearance.

Sorry: in the meantime I switched to classic CVA´s and the period correct neon springs in yellow/blue.

If you don´t know my 934, you can check some details here (pic 8 to 13):

https://www.tamiyaclub.com/showroom_model.asp?cid=130054&id=34024

But I´ve also a Kleinkram series 993, which is bone stock and running very nice, Ta02 is still so fascinating simple and good.

[ThunderDragonCy 8970]

@ruebiracer This is excellent! I have a cheap, bad quality 26t i would happily sacrifice to mod the gearbox. At the moment the high speed gearset is not likely to arrive until november, so have some time to sort it out. I might buy a cheap 13t motor to even up the speed with the stock gearing in the meantime. 

[Grastens 2821]

I heard about the re-release of the TA-02 High-Speed Gear Set through this thread. Thanks, @ThunderDragonCy!

In the meantime, I run a 13T motor in my TA-02S. I think I may have damaged it while running a 19T pinion, but it could still go an entire battery pack (3000 mAh for me) without activating the ESC's thermal cutoff.

Even with a heatsink (though not the standard TA-02 hop-up) and a new 17T pinion, the motor still runs hot, while obviously lacking the top end of the 19T gear.

I suppose my only advice then is to be vigilant with a 13T motor, and to go for whatever motor cooling devices can fit. I had to modify a stock Tamiya heatsink to avoid fouling the rear gearbox while also avoiding the open endbell of the motor I was using. Fortunately, the aluminum cuts relatively easily. A narrow heatsink could fit well - unless you are using a cockpit set in there, like me 

With a closed-endbell motor, you may be able to fit a larger heatsink - one with a fan would be even better, as airflow is a bit limited with the motor behind the stock chassis tub. The situation might improve with chassis plates.

I look forward to watching this build progress! I hope to be able to glean some information for my own car 

[ThunderDragonCy 8970]

@Grastens Thanks for the information. I am a bit concerned about motor cooling. What is the tamiya heatsink for this chassis?

I was thinking of this yeah racing fan mount to fit the end of the motor. 

[ThunderDragonCy 8970]

@Grastens Are you running the 13t motor with the high speed gearset? I would be running with the stock 74t spur. 

[Grastens 2821]

22 minutes ago, ThunderDragonCy said:

@Grastens Are you running the 13t motor with the high speed gearset? I would be running with the stock 74t spur. 

I am also using the stock 74T spur. When the high-speed gearsets arrive, I may drop to a 20T or 23T motor.

As for heatsinks: now that I think about it, I am not sure there is a dedicated TA-02 heatsink issued by Tamiya. I must have been referring to the aftermarket units that replace the stock motor mount:

I have one on order, but it has yet to arrive. I intend to install it in my TA-02S, at which point I can comment on its efficiency. It does seem counterintuitive to put one in an enclosed space, though I will give it a try.

With the TA-02's reputation for failing plastic motor mounts, I wonder if it will still improve the chassis, even if its heat-dissipating abilities prove sub-par...

Until I get to test it, I am thinking that a combination of that motor mount heatsink and a standard type that clips onto the motor will ultimately fulfill the intended purpose.

Edit: That YR heatsink looks like it will do nicely!

On a silky note: I could also drop to a lower-powered motor with the high-speed gearset... Or I could leave in the 13T and go gunning for the "World's Fastest Tamiya Lancia 037" record 

[ThunderDragonCy 8970]

@Grastens Interesting. I am getting a metal motor mount straight away, but not with fins. It will still be better than plastic though. Definitely getting a fan. Even when i get the high speed gearset and the 17t iconic motor it will get hot. 

[ruebiracer 1325]

Hi @Grastens and @ThunderDragonCy,

the Jägermeister and Vaillant edition came std. with a metal motormount and the better prop shaft! For additinal cooling, you can also refer to the solutions used in the RC Kleinkram series. RC Kleinkram even makes some nice tuning parts for their series, like a special fan mount and Lipo battery holder. (For stick Lipos used in the bathtub chassis).

They made their website new, so you can checkout here the special parts for TA02 and 03 Porsches:

https://www.rc-kleinkram.de/kategorie/sortiert-nach-rennserien/rck-kleinserie/porsche-cup/

There is a fan mount for the TA02 for 30 and even 40mm fans. Maybe not usable with @Grastens cockpit, but should solve all cooling problems nicely...

Greets,

Matthias

[Grastens 2821]

Thanks for the link, @ruebiracer! To nobody's surprise, competition DOES improve the breed. That chassis cover in particular is of interest to me; it may improve the TA-02's ability to tackle rally racing/dirt driving...

[ThunderDragonCy 8970]

42 minutes ago, Grastens said:

Thanks for the link, @ruebiracer! To nobody's surprise, competition DOES improve the breed. That chassis cover in particular is of interest to me; it may improve the TA-02's ability to tackle rally racing/dirt driving...

If you want better rallying, search Embie Racing. They do an awesome looking rally chassis

[Grastens 2821]

But if I wanted better rallying, then I wouldn't be driving Tamiya's Lancia 037 

That being said, thanks for the link! I see quite a few option parts and support for the RC rally scene, which is great 

[ThunderDragonCy 8970]

The kit arrived so I have started the assembly. Haven't recorded it all because it's going to be a fairly stock build to begin with. Rear end is together with ball diff and bearings.

Thought I would post this though. Front end going together I remembered I have a TA03 one way I tried in my Thunder Dragon. Thought it might be quite fun to give it a go so that has gone in.

If anyone has a spare ta/df gear diff cap (I have a spare case) in the uk I would be keen to have it. Then i can build a second gear difficult conventionally with some thick oil in it and try them both out.

[ThunderDragonCy 8970]

Finished up the build yesterday morning.

The only other mod I did was add bearings to the steering. I tried it out on a used manta Ray I had briefly so I remembered I had the parts. Carefully use a 6mm drill to openout the holes in the steering arms whilst still in the sprue. I drilled into a bit of scrap wood so I had something firm to push on

Then press in a flanged 630 bearing on the top side and then two ordinary 630 bearing from the other. 

When you install, use a Tamina 3mm shim (any from the 0.1/0.2/0.3 pack will do) top and bottom to keep the bearing clear of the static surfaces. Then tap the tub and screw in an m3x16 cap head until it is free to move with no slop.

Finished up the rest of affairs stock build with the low profile servo and 1060 from my TT01E. 

Wasn't sure how suspension would go so I trial fitted the car with some spare 55mm cva shocks. It's like tamiya made the shock towers wrong! Massive rear ride height, sort of about right at the front 

Swiped the 54000 M chassis dampers off my TT01E and got fiddling. In the end to achieve ride heights around 5-7mm with adequate droop I am running stock 50mm length at the rear and the TRF +2mm eyelets at the front wound out a few turns for around 54mm. 

After playing around with the body posts my FF01 Alfa shell didn't fit. Seems odd but the rear posts are either a little rearward with the offset adapter or a little forward with the straight ones. Eventually my 306 Maxi went on because it's got oversized rear post holes because it's been on about 4 different chassis. Does mean I need a new shell for this though....

It was an open practice at the track so I got a chance to run it. I started with quite a soft setup but it was soon snatchy and weird! Just like on my FF01 I had to move the pivot on the servo saver down and dial the dual rate right right down. Ended up around 50% which really helped. I also had the shocks a bit wrong to start with and oy alighted on the lengths mentioned above after a bit of remeasuring and trial and error. Eventually ended up with the hard and medium springs from the Short Spring Set 2 and it was all sorted. It's very slow with this gearing, but I did a bunch of laps and it's handling is quite nice now. I am taking the one way out immediately though! It sort of worked at the moment because it's so slow you hardly ever brake and are almost always on the throttle so the diff is locked, but any time I did brake it would randomly step out. I put the gear diff in last night with some 2 million oil in but it still has a lot of diff action so I will have to fill it some more. It is a big diff! If that doesn't work I will probably clean out the gear diffand swap it to the rear and put the ball siff in the front tightened right up.

It's got potential though. The gearset isn't due until November, so I am a little torn. I would like to run it, but would need to buy a 13t motor to max out the esc, and even then it would be on the slow side. 

The other annoying thing is that even with the ribs cut out the tub won't take any of my square lipos. Didn't really want to go the double deck chassis route, but not sure there's another solution.

[matisse 1723]

The steering mod is genius.

[Grastens 2821]

On 8/4/2021 at 9:56 AM, ThunderDragonCy said:

@Grastens Interesting. I am getting a metal motor mount straight away, but not with fins. It will still be better than plastic though. Definitely getting a fan. Even when i get the high speed gearset and the 17t iconic motor it will get hot. 

Having finally tried the metal heat sink motor mount in conjunction with my modified heat sink, I can tell you it somehow performed WORSE. I had a smoking motor by the end of the test run; will try a 20T motor and a larger pinion to make up some top-end.

It is possible the modified external heat sink I use touched the endbell of the 13T motor, which is also an older unit, but I never had the issue at this severity. The 20T motor may provide better answers.

In conclusion, I think a metal motor mount is still a good idea - just not one that functions as a heat sink. Good to see your car has no such issues! The types with fan mounts definitely look like the way to go.

Excellent work on the steering modification, too!