Toying with first build (TT02 SRX)

[Ty89m 3]

Hey all,

I'm an airplane and heli guy who's slowly starting to toy around with the surface side of the hobby, and I'm considering building up a new TT02 SRX chassis to use with a Killerbody Skyline or WRX body. I'm not entirely new to kits as I've built about 10 crawlers and the Tamiya 1/16 scale Tiger I tank, but these road going builds seem to present an insane level of options and variants!

With that out of the way, can anyone recommend the basic "must haves" if I want a run a decent brushless setup (probably a Hobbywing of some form)? Sounds like the Yeah Racing motor mount is a must, but is there any other weak links on the new SRX chassis that I'd need if I'm using a higher power brushless system? Are the stock SRX shocks good to go?

I'm guessing it comes with a spur and pinion in the kit, but if not, is there a good all-around gearing setup I should be shooting for? I have no intention of racing or bashing etc., just want a new kit to build (that isn't a crawler for a change) that is reasonably reliable for taking out to putz around on occasion.

I'll read through some threads, but if anyone has any advice in the meantime it'd be much appreciated!

Edit: I'm happy to spend a bit extra on the TA08 Pro or one of the higher end setups if need be, as long as it works with my intended body (from Killerbody  - "Fits vehicles with a 257mm wheelbase and a 190-200mm").

[Kpowell911 881]

Ive recently done something similar, feel free to have a read. I built in some upgrades. Scroll down to see the SRX Build  

 

https://www.tamiyaclub.com/forum/index.php?/topic/104012-my-tt-02-content-thread/

[Ty89m 3]

7 minutes ago, Kpowell911 said:

Ive recently done something similar, feel free to have a read. I built in some upgrades. Scroll down to see the SRX Build  

 

https://www.tamiyaclub.com/forum/index.php?/topic/104012-my-tt-02-content-thread/

Thanks - reading through that now! All good running the included gearing with the Hobbywing setup? Is the aftermarket motor mount only necessary if you're going with different gearing? Looks great though!

[Kpowell911 881]

I went with the aluminium motor mount because bling. Ideally it should be included IMO. Ive not ran it yet, waiting on a servo

[Pylon80 989]

Welcome to RC cars!

Which hop-ups are needed is always very controversial as everyone have their very own definition of what is "needed"

That said, the SRX's weakness is the same as every TT-02 variant: the steering arms and bridge have a large amount of play which is disappointing. You can get the Tamiya hop-ups which are very expensive and very good or the Yeah Racing one which is considerably cheaper. You can also go half-way by only buying the aluminum arms (54574) but not the bridge (54575). I have done that on one of my TT-02's and it is totally drivable. The full steering upgrade set (54752) is a good value but then on the SRX you already have turnbuckles and a proper servo saver so it might not be as interesting. Finally if you want the absolute best steering set go for the latest one Tamiya made (54965). I have it on one of my TT-02's and it is wonderful. You can also adjust Ackerman which is very interesting to play with. This would be my go-to on an SRX.

The motor mount is not really required. An aluminum one will not help cooling because it is hidden under the spur gear cover and the heat has nowhere to go. The bling factor is also a bit irrelevant because the same gear cover hides the motor mount completely. The Yeah Racing one allows adjusting the gear meshing which is needed when you want to depart from the kit 0.6Mod pinions and spurs to go with 48dp or 64dp pinions and spurs. This gets expensive but it comes in handy when you run out of gearing options. This happens when you want to race in a class mandating, say, 25.5t motors that need very tall gearing. Even with 29/64 you will still be on the short side. On the other end of the spectrum if you want to run a very hot motor such as a low turn brushed motor you will be geared way too tall even at 16/70. In any case, if your choice of motor fits the car gearing range (from 16/70 to 29/64) you will not need the Yeah Racing mount. One word of caution, if you overtighten the motor screws on a stock mount you can break it easily. So be careful and use a drop of Loctite on the screws rather than trying to tighten them too hard.

The shocks in the kit are the CVA's which are generally considered to be good. I have bought 3 sets and all of them had 3 good shocks and 1 bad one. The bad one would pull air bubbles making it impossible to get that fourth shock built properly. Once I figured it out and by using only the good shock bodies from each set I was able to build 2 sets of very good shocks... but then that is a bit unacceptable. I have never heard anyone having that issue here on TC :S so I am either unlucky or very picky, who knows. Also regarding the CVA's, the lack of threaded collars to adjust the ride height forces you to be a bit less accurate on setting up ride height, since the thinnest spacer provided with the CVA's is 1mm thick (about 1.5mm at the wheel). But then some detailed oriented people (ahem) add a thin shim (0.1/0.2/0.3mm) under the spring retainer to fine tune the height. It is just more work.

In terms of motor/ESC choice, it really depends on what your intended use for the car is. If you want to run it indoors on a proper racetrack then you will find that even a basic silver can is plenty fast when the car keeps slamming into the walls  On the other hand if you want to run it on large open parking lot just blasting around, it will soon feel like it isn't fast enough... no matter what amount of power you install in it! So again, the choice is totally dependent on what you intend to do with it.

I too come from Helicopters and Airplanes. You can fly circuits around the runway all day long or fly aerobatics/3D and never get bored. But I found cars a bit boring when running aimlessly on a parking lot. They do get extremely challenging going around any sort of closed track, be it just markers in a parking lot or a proper sanctioned RC track. Again this is very personal.

[Ty89m 3]

27 minutes ago, Pylon80 said:

Welcome to RC cars!

Which hop-ups are needed is always very controversial as everyone have their very own definition of what is "needed"

That said, the SRX's weakness is the same as every TT-02 variant: the steering arms and bridge have a large amount of play which is disappointing. You can get the Tamiya hop-ups which are very expensive and very good or the Yeah Racing one which is considerably cheaper. You can also go half-way by only buying the aluminum arms (54574) but not the bridge (54575). I have done that on one of my TT-02's and it is totally drivable. The full steering upgrade set (54752) is a good value but then on the SRX you already have turnbuckles and a proper servo saver so it might not be as interesting. Finally if you want the absolute best steering set go for the latest one Tamiya made (54965). I have it on one of my TT-02's and it is wonderful. You can also adjust Ackerman which is very interesting to play with. This would be my go-to on an SRX.

The motor mount is not really required. An aluminum one will not help cooling because it is hidden under the spur gear cover and the heat has nowhere to go. The bling factor is also a bit irrelevant because the same gear cover hides the motor mount completely. The Yeah Racing one allows adjusting the gear meshing which is needed when you want to depart from the kit 0.6Mod pinions and spurs to go with 48dp or 64dp pinions and spurs. This gets expensive but it comes in handy when you run out of gearing options. This happens when you want to race in a class mandating, say, 25.5t motors that need very tall gearing. Even with 29/64 you will still be on the short side. On the other end of the spectrum if you want to run a very hot motor such as a low turn brushed motor you will be geared way too tall even at 16/70. In any case, if your choice of motor fits the car gearing range (from 16/70 to 29/64) you will not need the Yeah Racing mount. One word of caution, if you overtighten the motor screws on a stock mount you can break it easily. So be careful and use a drop of Loctite on the screws rather than trying to tighten them too hard.

The shocks in the kit are the CVA's which are generally considered to be good. I have bought 3 sets and all of them had 3 good shocks and 1 bad one. The bad one would pull air bubbles making it impossible to get that fourth shock built properly. Once I figured it out and by using only the good shock bodies from each set I was able to build 2 sets of very good shocks... but then that is a bit unacceptable. I have never heard anyone having that issue here on TC :S so I am either unlucky or very picky, who knows. Also regarding the CVA's, the lack of threaded collars to adjust the ride height forces you to be a bit less accurate on setting up ride height, since the thinnest spacer provided with the CVA's is 1mm thick (about 1.5mm at the wheel). But then some detailed oriented people (ahem) add a thin shim (0.1/0.2/0.3mm) under the spring retainer to fine tune the height. It is just more work.

In terms of motor/ESC choice, it really depends on what your intended use for the car is. If you want to run it indoors on a proper racetrack then you will find that even a basic silver can is plenty fast when the car keeps slamming into the walls  On the other hand if you want to run it on large open parking lot just blasting around, it will soon feel like it isn't fast enough... no matter what amount of power you install in it! So again, the choice is totally dependent on what you intend to do with it.

I too come from Helicopters and Airplanes. You can fly circuits around the runway all day long or fly aerobatics/3D and never get bored. But I found cars a bit boring when running aimlessly on a parking lot. They do get extremely challenging going around any sort of closed track, be it just markers in a parking lot or a proper sanctioned RC track. Again this is very personal.

Great post, and thanks for all the info!

I agree, when it comes to pure excitement, it's a bit tough to beat flying in terms of pure excitement - but I've found building the surface stuff quite relaxing as I don't have to worry about the repercussions if something fails etc, and it's usually considerably less expensive than a 700 size heli With that said, running them on a course would be a lot of fun, and a great challenge. I have a feeling this car will be a shelf-queen first and a parking lot runner second, though I may get a second body or two when I want to run it hard.

Is there a good brushless kv rating I should be shooting for if sticking with the stock gearing? Does brushless require some drivetrain upgrades for reliability?

For my use case, is the TT-02 SRX ideal vs. something like the TA-08 Pro? Sounds like the ground clearance is better on the TT chassis, and as this will be a 4wd WRX, it probably makes sense to go TT.

I'll look into the steering hop-ups as well.

Heck, I may give the recommended Tamiya ESC a try, as it looks as though it'll run both brushed and brushless.

Again, thanks to everyone for the help!

[BuggyDad 2472]

On the steering parts, also shop around. I ended up with the new long arm Tamiya set on mine partly because it turned out that from Plaza Japan it wasn't much more money than adding up all the necessary parts for the lesser set up. Ordering from PJ only makes sense if you're getting a fair bit though - very cheap parts, but c.£20 postage. 

[Pylon80 989]

1 hour ago, Ty89m said:

Great post, and thanks for all the info!

I agree, when it comes to pure excitement, it's a bit tough to beat flying in terms of pure excitement - but I've found building the surface stuff quite relaxing as I don't have to worry about the repercussions if something fails etc, and it's usually considerably less expensive than a 700 size heli With that said, running them on a course would be a lot of fun, and a great challenge. I have a feeling this car will be a shelf-queen first and a parking lot runner second, though I may get a second body or two when I want to run it hard.

Is there a good brushless kv rating I should be shooting for if sticking with the stock gearing? Does brushless require some drivetrain upgrades for reliability?

For my use case, is the TT-02 SRX ideal vs. something like the TA-08 Pro? Sounds like the ground clearance is better on the TT chassis, and as this will be a 4wd WRX, it probably makes sense to go TT.

I'll look into the steering hop-ups as well.

Heck, I may give the recommended Tamiya ESC a try, as it looks as though it'll run both brushed and brushless.

Again, thanks to everyone for the help!

You will want to be around 6mm of ride height for on-road use outdoors, which both the TA-08 and SRX can be set to. Advantages of the SRX over the TA-08 that I can think of would be:

- The lower deck on a TT-02 is extremely cheap and so it will be less annoying when you scratch the underside (which is guarantied to happen if you run in a parking lot)

- The TA chassis have very nice, smooth and quiet belt drive systems but these are not very well protected and pebbles could catch in the belts and destroy the pulleys, so it all depends on how clean your prospective parking lot it going to be.

[Ty89m 3]

4 hours ago, Pylon80 said:

You will want to be around 6mm of ride height for on-road use outdoors, which both the TA-08 and SRX can be set to. Advantages of the SRX over the TA-08 that I can think of would be:

- The lower deck on a TT-02 is extremely cheap and so it will be less annoying when you scratch the underside (which is guarantied to happen if you run in a parking lot)

- The TA chassis have very nice, smooth and quiet belt drive systems but these are not very well protected and pebbles could catch in the belts and destroy the pulleys, so it all depends on how clean your prospective parking lot it going to be.

Ah, good point. I do have a warehouse with smooth concrete, so could do my driving there. Having a read through the manual, it would appear the kits don't come with a pinion, correct? I'll have to figure out which motor I'm going with and source the right one.

Edit: Disregard - pinion is a separate purchase only if you want to use the other spur. I am curious what a typical "general purpose" kv rating is for these.

[Kowalski86 1553]

17 hours ago, Ty89m said:

For my use case, is the TT-02 SRX ideal vs. something like the TA-08 Pro? Sounds like the ground clearance is better on the TT chassis, and as this will be a 4wd WRX, it probably makes sense to go TT.

The TT is more ideal for just bashing about on the street than any race kit, easy to fix, plenty of parts, and less to worry about.

Before looking into the steering hop-ups I'd assemble it as is and use a Kimbrough servo saver, the stock saver is very flimsy. Don't aim for precision with an entry level kit, aim for "good enough".

If you run brushless you don't need the included fiber disc, its worth holding onto it though if you go brushed or want to use it in a different Tamiya.

Definitely go with a Yea Racing mount for the adjustability, and the high speed gear set if the SRX doesn't have that.

Pick up a steel pinion if the SRX doesn't come with one, even on brushed aluminum pinions wear down quick.

Have a tray and clean desk to work on, these "fancy" TT-02s have a handful of spacers and shims to make everything work.

Look into cheap touring car tires for when the kit tires inevitably go bald, it's just the nature of driving on concrete.

Finally, take care with the screws during assembly and maintenance to avoid stripping threads in the chassis.

[Ty89m 3]

5 hours ago, Kowalski86 said:

The TT is more ideal for just bashing about on the street than any race kit, easy to fix, plenty of parts, and less to worry about.

Before looking into the steering hop-ups I'd assemble it as is and use a Kimbrough servo saver, the stock saver is very flimsy. Don't aim for precision with an entry level kit, aim for "good enough".

If you run brushless you don't need the included fiber disc, its worth holding onto it though if you go brushed or want to use it in a different Tamiya.

Definitely go with a Yea Racing mount for the adjustability, and the high speed gear set if the SRX doesn't have that.

Pick up a steel pinion if the SRX doesn't come with one, even on brushed aluminum pinions wear down quick.

Have a tray and clean desk to work on, these "fancy" TT-02s have a handful of spacers and shims to make everything work.

Look into cheap touring car tires for when the kit tires inevitably go bald, it's just the nature of driving on concrete.

Finally, take care with the screws during assembly and maintenance to avoid stripping threads in the chassis.

Yeah - I don't think I'll be doing much bashing, I really just want something different to build for a change. It was either one of the TC setups or a nicer 1/10 buggy. As said above, we have a warehouse that's smooth concrete (probably great for the drift crowd), so no issue with debris etc.

for those running either of these cars, are you typically running 13.5 and 17.5 turn motors? I'll certainly ensure I grab a steel pinion if needed.

[Kowalski86 1553]

10 minutes ago, Ty89m said:

for those running either of these cars, are you typically running 13.5 and 17.5 turn motors? I'll certainly ensure I grab a steel pinion if needed.

I run mine brushed, but 17.5 would probably be ideal since thats not a huge step from stock. I'd start there and bump up the power as you get more used to how your car drives.

I checked the specs, the SRX comes with a hard coated aluminum pinion so I'd stick with that for now. I prefer steel but coated aluminum pinions usually hold up well.

It also comes with the high speed gear set, so that's some extra speed off the bat, and halfway to being open to running whichever spur gears can fit under the cover.

[Pylon80 989]

23 hours ago, Ty89m said:

Yeah - I don't think I'll be doing much bashing, I really just want something different to build for a change. It was either one of the TC setups or a nicer 1/10 buggy. As said above, we have a warehouse that's smooth concrete (probably great for the drift crowd), so no issue with debris etc.

for those running either of these cars, are you typically running 13.5 and 17.5 turn motors? I'll certainly ensure I grab a steel pinion if needed.

The TA-08 seems to me like a much better value than any TT-02. In particular it has the new style upper arms that enable you to dial in camber with an hex wrench similar to a TB Evo 8 (XRay's have had for years now... and even the TRF 420x doesn't have it yet). As we discussed, if you have access to a clean surface that won't harm the belts and pulleys the TA-08 would probably be the nicer car. It is a little bit more $$ than the SRX but the SRX absolutely needs the steering upgrade so its price is misleading. On the other hand the SRX provides the peace of mind of a cheap and sturdy lower deck combined with a well protected drivetrain. You could even rally with it, people have done it with type S type of TT-02's (so Type S/SR/SRX/custom builds using the TB arms). Both great choice, really.

Keep us posted!

[Ty89m 3]

1 hour ago, Pylon80 said:

The TA-08 seems to me like a much better value than any TT-02. In particular it has the new style upper arms that enable you to dial in camber with an hex wrench similar to a TB Evo 8 (XRay's have had for years now... and even the TRF 420x doesn't have it yet). As we discussed, if you have access to a clean surface that won't harm the belts and pulleys the TA-08 would probably be the nicer car. It is a little bit more $$ than the SRX but the SRX absolutely needs the steering upgrade so its price is misleading. On the other hand the SRX provides the peace of mind of a cheap and sturdy lower deck combined with a well protected drivetrain. You could even rally with it, people have done it with type S type of TT-02's (so Type S/SR/SRX/custom builds using the TB arms). Both great choice, really.

Keep us posted!

Indeed I will, and yes, the TA08 is the direction I'm leaning. It's still reasonably inexpensive all things considered.

I've also looked at the highest end setups from Tamiya and Yokomo as well, but I'd almost feel guilty getting a top tier race chassis with no intention to race (nowhere nearby to race anyway). Seems like a overkill, but they certainly look nice!

[Rvl 2 15]

I have 2 SR and the SRX and a tt02 and a tt02b , right at the moment all Trf dampers are sold out , CVA dampers are ok but difficult to accurately adjust ride height. The Ta08 comes with TRF dampers(shocks) , the TA series are about 100gms lighter than the SR , I was looking at a members TA06 yesterday  and I think my next buy will be a TA07 or TA08 (my son has the TA08 , SR and SRX)

 My first suggestion would be to join a track , I do like driving my cars in front of the house. But find it much more enjoyable to build my cars at the track and chat with other members. Also if you do get into racing , then you build each car to class rules. Each class has specified motors , esc , tires , body and weight specifications. 

[one_hit 913]

On 5/18/2023 at 2:45 AM, Ty89m said:

Indeed I will, and yes, the TA08 is the direction I'm leaning. It's still reasonably inexpensive all things considered.

I've also looked at the highest end setups from Tamiya and Yokomo as well, but I'd almost feel guilty getting a top tier race chassis with no intention to race (nowhere nearby to race anyway). Seems like a overkill, but they certainly look nice!

If you decide to get the TA08, keep in mind that spares are difficult to obtain and expensive. A spare TT-02 tub is less than $4 from Plaza Japan. The hophup hard version is less than $5 while a TA08 tub is around $40-50. The tub on the TA08 is its achilles heel, it is known to break at the rear suspension mounts. I’ve been looking for a spare one but no luck. Same with the A parts, can’t find those anywhere. A hard crash will break those upper arm mounts which come on the A parts tree. Most of the TA08 parts trees, as well as the chassis, are 7 digit part numbers which means they are not regular spare parts. 
 

Compare that to TT-02 spares which are cheap and readily available. In fact I’ve recently built a Type S and a regular TT-02 entirely from spare parts. That’s why at the track, I feel a lot more relaxed when driving my Type S because if I crash into the wall, it won’t cost much to repair. When I drive my TA08, I have to always be extra careful because a hard tap at a rear wheel could break the chassis and sideline my TA08 for weeks or months.