ANOTHER TT02 speed run build…

[Skimax 30]

Hey everyone, I am new here but have been involved with touring cars for a few years now and have always wanted to pick up one of the cheap Tamiya kits… I finally did so and have decided to make this into a speed run project!

I picked up one of the CLK AMG kits and got to work, including several hop ups that I have come to understand are almost essential in adding to the cars ability to steer better and maintain more longevity when a lot of power is added to the chassis. A list of the initial upgrades are as follows:

Full bearing set

Aluminum drive shaft

Aluminum propeller joints

Aluminum steering rack 

High speed gear set

Aluminum wheel hexes

Yeah racing motor mount

Front turnbuckle set

servo horn and turnbuckle

An old fan I had laying around

SkyRC GPS

 

With all of that I got to work completing the kit and for now I am using the stock ESC (hobbywing 1060) and stock motor (Tamiya torque tuned). I wanted to methodically go through different options in my speed journey because A. I’m a nerd and like to compare the data and B. I want to work my way up in speed and ability to control a car moving so fast and tweak the drivability as I go. So I got to work on the “baseline” scenario which included all of the above modifications and uses the stock pinion and spur. The results are as follows:

2S topped out at 20mph

3S topped out at 30mph

 

so I could already tell that 3S would make a huge difference in the abilities with this car and I will definitely need to use that for any serious speed run attempts… from there I wanted to do an incremental upgrade with the gearing and that entailed replacing the stock spur (70t) with the 68t that came with the high speed gear set. I knew this would be incremental but was interested in how much a change like that would impact things. This brought the FDR from 8.27 to 8.04.

2S topped out at 22mph

3S topped out at 32mph

 

Now the increase was small but it was a step in the right direction and I k ew gearing was going to be key in extracting all I could out of this stock motor… I already own several other pinions from other cars and they are all 64P so I chose to use that as a point of departure in the gearing changes and bought an 80t spur to use with my existing pinions. With the pinions that I already had I knew that I could get anywhere in the range of a 7.43 FDR all the way down to a 4.00. I popped the new spur in and of course some of the smaller pinions were not even close enough to make contact with the spur and was forced to just go for gold and put the 52t pinion in lol.  Because why not?! I left off the gear housing because it wouldn’t go back on due to the large pinion and this also omitted my fan which probably didn’t help tbh. The car already felt faster just raving it at my desk and now I have come to find that the stock tires are ballooning so much that I swapped in some belted USGT tires from my xray to handle the increase in power. I’m sure I will be going down the tire rabbit hole before I know it… anyways I went out to run this setup and came back with a pretty decent result IMO:

2S topped out at 35mph

3s topped out at 45mph

 

This maintained the 10mph speed difference between the batteries that I have observed in the previous tests and honestly I was super happy to be at 45mph on the stock brushed setup. The motor however was extremely hot and that may have been due to not having the fan on but I’m sure that the 4.0 FDR is absolutely stressing the badword out of that motor and I honestly don’t think that I can get much more out of the motor. So with this I trimmed the stock gear cover to work with the big pinion and have the fan back on there for any future runs.

 

i guess a question would be what can I do to suck anything more out of this motor? Is it even worth it?? I know I will need to go brushless to really get the speeds I am looking for but wondering if there is anything I’m missing with this setup right now…

I will use this thread to provide any future updates on the build and looking forward to continuing on down this path. I also need to find another place to run as 45mph was pretty much maxing my usual spot!!

[Scottrc 232]

Great write up. 45mph! That’s an amazing speed for a brushed motor! Didn’t think a brushed motor could get anywhere close to that. I’m building a TT02 speed run car too but going the brushless route using parts I pretty much have laying around. Hoping to get it together for a run next weekend. 

[alvinlwh 6849]

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[Skimax 30]

3 hours ago, Scottrc said:

Great write up. 45mph! That’s an amazing speed for a brushed motor! Didn’t think a brushed motor could get anywhere close to that. I’m building a TT02 speed run car too but going the brushless route using parts I pretty much have laying around. Hoping to get it together for a run next weekend. 

Thanks! Yeah I was pretty surprised with 45… good luck on your build!

[Skimax 30]

17 minutes ago, alvinlwh said:

I don't think you can get anymore out of the silver can. I got 30mph in a M chassis sized thing and that is about the max it can reasonably turn. Yours TC sized wheels are bigger so your top speed will be higher than mine?

In theory, I can get 38mph out of mine with a FDR of 2.4 in that chassis, but when I geared it that far, it actually ran slower and burnt the motor out. I find that FDR of around 3 is the max the silver can can do, and not for long.

(My numbers are based on MTC wheels, your TC wheels will be different)

Isn’t the M chassis 1/10 scale as well? I would think the wheel sizes would be pretty similar, I’m not sure though.

also, are you using the basic silver can? I have the torque tuned in the car and I believe it’s a small step up in speed over the base can and the sport tuned is an even further increase. What was the gearing that you were using? How about batteries, are you using a 2S or 3S?

[alvinlwh 6849]

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[Skimax 30]

15 minutes ago, alvinlwh said:

MTC wheels are 55 or 60 diameter, so a bit smaller than TC sized wheels of your TT.

Yes, I was using the silver can, got a bunch left over to experiment with (and burn them out). They are cheap or free which is great when I was messing around and learning about gear ratios. I was (this was a year ago) using 2S, only dipped into 3S recently.

Ahh yeah, I guess all of these would probably account for the 5mph difference we were getting.

[Skimax 30]

So I’m thinking about picking up a mamba monster 2 and a 2500kv motor that I found for sale… should net me a nice bump in speed over the brushed torque tuned!

[GrandOlDaz 24]

I have yet to build my tt02...waiting on a steel spur (64) and pinion set (couple diff ones in the set)

 

Will eventually go brushless, but I think it is pretty cool seeing how far you can this chassis with brushless

[Skimax 30]

Welp I geared it to 3.7 FDR and was doing passes on 3S…

the session came to a close when the car stopped moving and the motor started smoking lol. Guess I need to hurry up my brushless conversion! Currently have a live on a mamba x.

[Skimax 30]

Took the motor out of the car tonight and there was a piece of magnet? Embedded in the bottom of the chassis 

 

[alvinlwh 6849]

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[Skimax 30]

9 hours ago, alvinlwh said:

That on your picture is not a magnet, your motor had thrown a brush. I had that happening quite a few times when I tried out silly gearing.

Ah nice! Thanks for clarifying.

seems like an excuse to go brushless!

[Skimax 30]

So I have a mamba X and a 3800kv motor coming tomorrow. On 3S I think that should probably get me close to the 100mph goal.

i also got the Tamiya chassis cover and I’m planning on just running that as the body. Seems to seal out a lot of the air coming into the body and gets rid of one of the big holes which is the wheel wells. The shell also fits tightly against the tub with Velcro so it’s very streamlined!

 

[alvinlwh 6849]

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[Skimax 30]

22 minutes ago, alvinlwh said:

Unfortunately I doubt it. According to my calculations, that will get you 50+mph, maybe 60mph. However do keep us updated on what you achieve. Good luck!

Im getting about 85mph with the gearing that I have on the car right now. If I add another 10 teeth to the pinion it says I should be at 101.

We'll see!

[alvinlwh 6849]

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[Skimax 30]

Finally got to run the castle system. Went to the spot that I was running the brushed system and there was no way to get a top speed there. Could only max out at 49 before slamming on the brakes so I didn’t run off the road.

Found a frontage road that had minimal traffic and sent it. Ended up with 76mph on the first pass and actually spun the wheels when I went what so I know this thing has a lot more in it. Was much easier to control than I was imagining so that’s cool. Then I went home and looked at the data in Castle Link. Cool as **** tbh. Excited for what’s to come.

 

[Skimax 30]

Here’s the setup…

 

[Skimax 30]

Made a few modifications to the steering and added foams to the car and went out for a couple of runs today… disappointingly slower than before by about 4mph. I think I’m going to need to go to the gearing next to get me where I need to be.

Also had a little bit of damage that cut the session short. Luckily I just ordered spares of that parts tree lol. Or maybe I just go for the aluminum hubs from here.