great knowledge share here

I had a break from the TRF421 and decided to race my TT02 against competition touring cars at the largest UK indoor race track.

I was pleasantly surprised:)

https://www.thercracer.com/2025/02/y...eview.html?m=0

https://cimg6.ibsrv.net/gimg/www.rct...e9d9778e2.jpeg

Great write up!!

What kind of differences in setup would be needed for asphalt?
Also, those springs are xray springs correct? Do you have a part number?

Cool stuff - sorry if I missed it, but what was your final ranking, out of how many drivers? Any lap times / 5mn time to share, and how does it compare to the top dogs? Or were you actually the top dog? ;)

Great Write up, I was in the final with you by the looks of it!

Impressive driving giving the chassis used, very impressive

Good stuff. The TT-02R and other variants are pretty capable once you chase down the gremlins and "un-crap" the setup. I found it pretty accepting of setup changes etc.

SRX TT-02
 

I'm late to the TT-02 game, looking for help on the build. Do I use rubber cement where arms go into chassis? I'm trying to shim some of the slop out of the arms but the drivetrain had a ton of slop around the spur gear, is that normal? It seems I will also be rebuilding the gear diff as well as that isn't very smooth either. Any tips would be great! TIA

No rubber cement!! To get the play out use shim kits.. they come in varying width of 0.1, 0.2, 0.3.

https://www.tqrcracing.com/shop/prod....asp?p_id=1809

https://www.tqrcracing.com/shop/prod...w.asp?p_id=623

https://www.tqrcracing.com/shop/prod...w.asp?p_id=622

Has anyone tried the new (42353) SSBB dampers with the (54947) v2 carbon shock stays (towers)? Is this a direct fit on my SRX? Thanks in advance!

The Tamiya TT-02 S/SR/SRX kits use different Carbon Damper Stay (Shock Towers) as compared to the stock TT-02/R/RR kits (Item 54947). Item 54947 is designed for the plastic upper arms on the basic TT-02 kits. Please refer to this link on Tamiya's website showing how Item 54947 is used...
https://www.tamiyausa.com/shop/optio...amper-stay-ii/

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Below are the carbon fiber parts you need from Tamiya for the TT-02 S/SR/SRX kits.

Tamiya Item# 54632 RC Carbon Damper Stay Front TT02 Type-S
https://www.tamiyausa.com/shop/optio...-stay-front-3/

Tamiya Item# 54633 RC Carbon Damper Stay Rear TT02 Type-S
https://www.tamiyausa.com/shop/optio...per-stay-rear/

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I have not personally used the SSBB shocks on any of my TT-02 S kits, but here is a link the THERCRACER.com website where he has used the Tamiya SSBB shocks on his kit. While their car is not specifically an SRX kit, it is using the same lower suspension arms. Also note that THE RC RACER used (2) front shock towers mounted upside-down to accommodate the shorter length of the shocks. Here is the link...
https://www.thercracer.com/2020/03/u...02-type-s.html

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Note: There are several aftermarket carbon fiber shock towers available that are less expensive than the official Tamiya parts, but I have never used any so cannot vouch for the quality.

SRX kit
 

I’m looking for assistance locating this part, not sure why it’s not easier to locate.

19804940 tamiya
MB11 Ballstud

Thanks,
Chris

Looking through the Tamiya TT-02 SRX manual, the part are asking about (19804940) is a Tamiya short 5mm ball connector nut and appears to be the same as Tamiya item# 42323
https://www.tamiyausa.com/shop/alumt...onnector-nuts/

It looks like that part is out of stock on TamiyaUSA's website. However, I bet you couldn't find part# 19804940 on TamiyaUSA's website. That is because Tamiya part numbers are usually listed as a 5, 7, or 8 digit number. So to find that particular part on their website, drop the 1st digit (1 in this case) and search for 9804940. Here is a link to a reference site confirming this information...
https://www.tamiyabase.com/parts/15086-19804940

It looks like you can buy this part directly on TamiyaUSA's website here...
https://www.tamiyausa.com/shop/7-dig...tor-nut-42301/

I was able to find part# 42323 at TQRACING (directly and thru Amazon 3/6/2025) here are some links...
https://www.tqrcracing.com/shop/prod..._keyword=42323

Which TRF dampers are the current go-to for a standard TT02 (non-s)? It looks like maybe the 42102, is that correct? They’re for an asphalt Porsche cup car, so will be looking for ~5mm ride height and wanting to make sure I get the right length shocks. Thanks!

TT-02
 

What parts are required to run on the rear for the active toe?

Check out this article on TheRcRacer website, which includes photos & parts/#'s used for the mod...

https://www.thercracer.com/2022/07/t...trol-rear.html

They added active rear steer to a stock TT-02, but did admit in their review that any improvements could be simply because the mod had more rear toe than a stock TT-02.

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TheRcRacer also added active rear toe on a TT-02-S kit (but it should work the same on an S/SR/SRX) kit. Here is a link to that article showing pictures and parts used...

https://www.thercracer.com/2020/03/u...02-type-s.html

is it better to use a shorty battery pack to race with ?
do you move it to ward the front or rear. carpet track stock motor?

I suppose it all depends on how you define "better". Using a shorty lipo should reduce the car's overall weight and another advantage is that the space not used by a standard lipo can then be used to place electronics like ESC or receiver to ensure everything is as low as possible in the chassis. The lower the better. You can also move the battery wherever you like, front to back, using spacers that can easily be made from simple Styrofoam blocks (or whatever) of various widths to tune how your car handles.

Yeah Racing sells an aluminum shorty battery pack kit in blue and red that uses a large O-ring to secure the battery that looks nice. I've often found that the aluminum bits are heavier than the stock plastic ones, but in this case you're likely OK. Another option I found was a seller on Etsy who has a 3D printed kit to accommodate a shorty pack. Looks nice and should be light weight too.

Might be worth a try.

I ran mine with a shorty pack in parking lot series and rally class on carpet and it drove well. But, my friend who is a far better driver than me runs a low profile full size pack on carpet.

That is the biggest question. It's all dependent on what you want from your TT02.
Some like the shorty for lighter weight, I personally like the stick pack from Protek 5000mah LiHV for better weight balance.
I tried a shorty, a heavier brick style lipo and my Protek and personally I feel the extra weight balances out the chassis for better left and right. Try each and see what your preference is.

Has to have wires and a plug to be legal everywhere Ive been.

I use the Protek Mudboss stick lipo.

My friend uses low profile Zee batteries.

I went through this with all variations of lighter and heavier shorties and I made different battery bars that would position them at various spots forward or rearward. I did this while trying to balance out the car perfectly on the scales depending on the shorty weight. The car drove well but then the one race I had forgotten to actually hit start to charge my battery so I threw in my full size Protek battery which made the car heavier and unbalanced on the scales but it drove so much better and that final came down to just a nose that night. I've kept racing with the full size pack ever since because it just feels better to drive. So I say if you have different batteries experiment and see how the car feels to you when driving when your tires are in a similar state.

For the TCS race at 180 Raceway I ran the Gens Ace Redline 2.0 6500mah battery and my car was the fastest GT ProSpec there, just not the driver...LOL :lol:. I qualified 3rd and was very close to the front two runners but screwed up in the main and fell back. But if you are running GT ProSpec and following the 1400g minimum weight rule then the way to go is a full size pack that gets the car to the minimum 1400g. The bigger packs have lower IR's and much less voltage drop off.

If you don't have a weight limit rule, then run the shorty pack to the rear. Before the implemented the 1400g minimum weight rule by GT ProSpec was under 1200g with the small shorty pack.

Can you tell me what nuts/bolts you used for the for the pass-through steering mod? Also, assume this just provides more strength than the 54550 TT02 Low friction Step screws?

https://cimg0.ibsrv.net/gimg/www.rct...903495ab63.png

Ah, ok... I see this is how the Type-SRX has it....

https://cimg0.ibsrv.net/gimg/www.rct...1c2787d25e.png

When threading the 3x23mm steering screws from the bottom of the chassis, it DOES help to apply some grease/lube on the screw threads. Pay attention when starting the screw into the hole that it isn't off center/at an angle.

This is a better option than using the screws that screw in from the top. The top down screws don't go all the way thru the chassis and have the potential to break the chassis/hole where the screws go in. This includes the small set screws that are included with Tamiya 54574 or 54752. In fact, I would highly recommend getting a new chassis if you are upgrading from the stock self tapping steering screws when going to 3mm machine thread steering screws.

Here is some part info on TT02 stock steering screws & the low friction option from Tamiya
Stock screw is a 3x18mm step screw - Tamiya 9805573 (https://www.tamiyausa.com/shop/7-dig...p-screw-44028/)
Low friction TT02 upgrade has a hex head - Tamiya 54550 (https://www.tamiyausa.com/shop/optio...ep-screw-2pcs/)

Here is the part number for the flanged tube - Tamiya 9803242 (https://www.tamiyausa.com/shop/7-dig...ed-tube-47439/)
**Note: I would either suggest purchasing one of the Tamiya TT02 Aluminum steering upgrades or aftermarket aluminum steering upgrades which will include the appropriate bushing/tubes as part of that hop-up.

On the diagram above using the 23mm screw it seemed easier doing it the opposite way since the bottom of the chassis has the cutout for the nut. So the screw and washer going from the top down into the nut in the recessed area on the bottom.

While you can use the 23mm screw from the top and the nut at the bottom of the chassis, it will make it more difficult to remove the steering arms. Because the screw is threaded into the plastic, you will have to totally back out the screw if you want to perform any maintenance on the steering arms/components. Having the nut on the top makes performing any maintenance on the steering simple/quick which is important when racing.

can you share item number for 39mm dcj? do you use stock front diff? what diff cup do you use?

have you figured out if Tamiya 42372 RC DOUBLE CARDAN JOINT SHAFTS with 54477 out drive work on stock tt-02 suspension?
shout 22054 37mm shaft be used as the double joint part makes it longer?

Tamiya has them for about 10 bucks

Worked on my new SRX for my local club's TT-02 class.

https://cimg5.ibsrv.net/gimg/www.rct...ade0f6273.jpeg
https://cimg9.ibsrv.net/gimg/www.rct...fa46571e1.jpeg

TT-02 Spins to CCW, pushes CW
 

Hey guys this one has me stumped. This car will spin when pushed hard on left hand turns or with abrupt throttle during a corner, but to the right it will never spin no matter how hard I mash the throttle. On a hard turn in with no throttle it will start to slide turning left, but it will never do it to the right. I've put it on my arrowmax setup station and the numbers are all good. I have the Tamia CVA super mini shocks. The car goes straight under throttle and off throttle. The turning radius is exactly the same, I physically match the diameter of the circles on flat concrete. There's no excessive play. The lateral balance is pretty close, not enough to cause this kind of nonsense. All four hubs are mounted properly, none of them are upside down. I have a spool on the front and very light grease in the rear. Heavy grease in the rear didn't make a difference. I know the wiring is ugly, I just converted it from a shorty with the ESC on the battery side and I'm not going to dial it in until it handles. This is on contact 32s and yokomo 28a's. There is no servo binding at the endpoint, I make sure to back it off to zero buzz before I do the physical circles to even the steering completely. I just printed some -2° knuckles and it did not change the handling. I've used the setup station before and after these knuckles and they are perfect at -1 camber and 2° toe in per side. I was hopeful that a lot of rear toe and would help but no. I'm running a savox 1258 and It centers great . The shocks are all the same length. I have it set up with a reasonable for this chassis ride height and it has about a third of the travel in droop. Basically when I lift the car the springs have just a little free play. This setup works reasonably well on any other touring car I've used for a base setup. Interestingly I have a Euro Truck that does the same, but I purchased it used and the guy who had it was a cheater and it has weights that I took off and the rear chassis has part of it glued together so I can't disassemble it and check it out. On that vehicle I assumed it was just something the guy had done. Now I have the same problem with this car. I've built of cars, I have x-ray t4, TC3, tc4, x-ray F1, cero V2 and sport. I've probably built another 50 cars over the years for off-road. I'm ready to throw this thing at a wall. I even went so far as to add extra preload to only the front right shock and it's still did it. I've swapped the shocks around. Ugggh. I hate this car!!!
https://cimg6.ibsrv.net/gimg/www.rct...1ee0bf3d51.jpg

Front diff should be heavy grease "almost" locked, rear diff nothing at all. Even the lightest grease in the rear makes these cars step out.👍

Also ditch the rear bumper, it's a chunk of unnecessary weight that works on the pendulum, if you want the rear to stick you need front weight not rear weight.

Also look to be missing the screws in the rear arm mount up front.

And the rear too.....

while a fun car to drive its best just to replace the chassis and all the a arms and upper control arms. start fresh. that should resolve all your issues. these cars have a tendency to clap out over time. nit sure what rules u have to follow for racing? however we run spools and tamiya oil diffs

TT-02 Spins to CCW, pushes CW
 

https://cimg6.ibsrv.net/gimg/www.rct...556c991b7e.jpg