NEW speed run project 100MPH // Tamiya FF03 // advice and tips are welcome

[Fabia130vRS 2098]

Hi,

some may remember my account. I haven't been active lately, life obligations got onto me, good ones tho.

A friend (John, later in text) and I are back on the speed run thread. After a pause in this hobby, John decided to make his comeback with a Xray T2 007 and a brand-new factory built 3Racing Sakura Advance S, as I understand it is a decent entry level race car. Nothing too fancy, I don't know his final setup yet, but I want to give this challenge a try with my old FF03 that in the last speed run challenge hit 103km/h.

I think it was 2020 when we had the last challenge... John drove a AE TC6.1 with a 3s setup and managed to achieve a speed of 113km/h, while my FF03 achieved 103km/h.

I don't remeber the rations now, but my setup was a 3s Tamiya TBLE01 / TBLM01 8T sensorless brushless combo. This time it is similar (I unfortunately sold the tble01 combo) with a Carson Dragster 10T motor, it is actually a rebranded TBLM01 10T. I can guarantee this, as the ESC Dragster Carson is identical to a TBLM01.

I can not use the TBLE01 esc, it burnt out and haven't found somebody experienced enough to reroute the connection and restore the board. (picture below)

https://imgur.com/Xxq94ZH

Anyways, the setup

China ESC 120A 2-4S (4s will be eventually used, chaos mode )

Carson Dragster 10T 4300kv 2-3S (4s will probably work also but once  )

Savox 1252MG (low profile servo, mounted with @wtcc5's technique)

GEAR RATION: Spur 64P 72T  //// Pinion 64P 60T /// FDR 1.20

                    diff Spur 52T /// Pinion 20T /// FDR 2.60

FDR: 3.80

(this should on 3s run 103MPH /// 172km/h)

There is a Yeah Racing diff set with a 50T diff spur, that would bring the FDR down to 3.70. I already have the tamiya 54471 steel gear diff.

 

My question where I need advice is, what kind of gear diff putty should I use or only oil? if oil? what kind of oil? I obviously will not be racing through corners, I need something that will hold stable under load in straight runs.

 

and please share thoughts and ideas about this setup.

72T 64P vs 35T 48P (for reference)

The Chassis

Since this will be a 100MPH run, I have put a bit of thermal paste on the heat sink for MAX efficiency

The motor

The ESC (  ) funny how it can be the same price for 45A 60A 80A and 120A, this is a hit-and-miss

Other parts on order

This is what racing on a budget looks like  if this thing hits anything near 100kmh I will be more than happy.

Taking suggestions for body choice!!

Tire recommendations are also welcome!

[MadInventor 3884]

My 2 cents on the diff (I had an entry in the speed run with a DF-02 that did 80Km/h + would be to forget the putty and just lock the diff. I ran my DF-02 with locked front and rear diffs. You're mostly going to be going in straight lines anyway and not going to be worrying about cornering ability. 

Good luck.

[Fabia130vRS 2098]

Correct, thank you.

As I understood, this diff putty is less viscous as oil. Would close the diff more than just oil, which annoyingly leaks in micro amounts.

I did run already speed runs on the stock built diff. I guess it was pretty open with stock oil which came with it. 

 

eventually, using putty will eliminate the process of purchasing new oil seals for the diff housing.  

[Fabia130vRS 2098]

I was thinking this   could do it? Not to expensive to crash at 25€

 

 

 

[MadInventor 3884]

Looks nice, although You might want to think about changing / losing the rear spoiler. The car is front wheel drive, so the spoiler being quite savage looking will provide a lot of downforce / drag abouve 50mph, and all the downforce will be behind the rear axle, giving a tendency to try and lever the front wheels off the ground.

 

[Fabia130vRS 2098]

Thank you for pointing that out. It did happen to us already, 2–3 times the car caught air time and landed on its roof. Definitly it would be good to cut down on rear downforce. It did never happen to the FF03 it's quite nose heavy but still it could act as an aerodynamic break.

This is the old body I used to drive on speed runs. And a picture of the previous chassis setup.

I believe the 8T is rated around, 5700kv, but I used at this time a 35T 48P pinion with 68T 48P spur. 103kmh on 3 s. Now I will be running a 10T with 4300kv, that should improve torque ability but is it enough for 60T 64P and 72T 64P ?? That's 1.20 FDR in total 3.80 Final.

 

I also ordered these parts together with the TRF418 carbon reinforced uprights off RCMART. To improve steering abilities and cooling.

[Nicadraus 6197]

If using stock diff, the plastic cups will eventually get broken easily at that speed. I would upgrade the diff cups to aluminum. 

Yeah Racing: FF03-069BU

Tamiya: 54233

The YR is better in build and design. Also comes with tension screw and sealed bearings.

The aluminum steering set you posted is a big plus as well. Lastly, replacing the stock bumper mount to aluminum helps dissipate heat quicker as it becomes a heatsink extension to the motor mount and more rigid as well.

[Fabia130vRS 2098]

tamiya 54471 steel gear diff with steel cups is installed. Not sure what putty to use, do you have a link?or do you use oil only? Can you recommend thicker oil?

[Wooders28 4722]

On 1/2/2023 at 6:26 PM, Fabia130vRS said:

I haven't been active lately, life obligations got onto me, good ones tho.

Good to have you back bud!!👊

Don't think I've done any runs since either tbh.....😳

 

On 1/2/2023 at 6:26 PM, Fabia130vRS said:

My question where I need advice is, what kind of gear diff putty should I use or only oil?

Not sure on the price of your diffs, but on the DT03 speed runs, I just filled the thing with superglue.

[Fabia130vRS 2098]

Thank you.

 

You can glue the stock plastick ball diff, I done it. Glue + a small screw throught the whole thing.

 

But in the gear diff no chance. Its a nice mechanical piece. I think I will just go with  for example Tamiya 42212 or similar

https://www.tamiya.com/english/products/42212/index.htm

[Nicadraus 6197]

18 hours ago, Fabia130vRS said:

tamiya 54471 steel gear diff with steel cups is installed. Not sure what putty to use, do you have a link?or do you use oil only? Can you recommend thicker oil?

250k oil will be stiff enough and should do it. 

https://xtr-rc.com/en/xtr-racing/1384-friendly-url-autogeneration-failed.html

[Fabia130vRS 2098]

I stil would prefer putty as ži have read only pro's for it rather the con's. I have to buy it anyway, so it does not matter. But oil does leak tiny bits, this is mostly why.

 

Are there any comments on the 72T / 60T spur pinion ratio? At this moment, I am not even sure if it will fit. It does look like there is enough place, but tbh I don't know the 60T 64P pinon width. I just hope it will not need a kick-start to start driving. 3,80 FDR is not that low, or is it? I know in racing the FDR is limited to somewhat around 4 FDR

 

When we used to do speed run in the beggining, We used F104 and F103's with ratios around 2 and lower in FDR.

I still have on my F103 35 / 90 T 64P. having no gearbox thats 2,57 FDR, slower in lower and mid speeds, but on high speed top speed burst immidately. a 13,5 T sensored trackstar 80A esc combo limited to 2S.

Due to the nature of the chassis, It's hard with a F103 (F104 conversion 170mm width) to keep stable on high speeds, top speed with crash on the F103 is 86kmh. 82kmh without crash. On 2S with gyro.

 

 

I like how the FF03 is FWD and still such an amazing chassis, the gearbox is great in my opinion, such layout of gears has also been seen buggy, isn't it?

[Nicadraus 6197]

1 minute ago, Fabia130vRS said:

I stil would prefer putty as ži have read only pro's for it rather the con's. I have to buy it anyway, so it does not matter. But oil does leak tiny bits, this is mostly why.

My set up in my Pro-R and XV-01 diffs are same using steel gears with aluminum gear covers. Never had leaking problems at all. In fact both cars have not had any diff overhaul since mid 2021 with quite number of runs on the track already.

But if putty works for you, then do it. Another alternative is blue tack or Tack-it. I've done this in my LRP S10 kit. Locked the front diff with blue tack.

[Fabia130vRS 2098]

Thank you, I may investigate the tack-it option. I can expect to have greater tire wear on the front tires, but this should be better.

[Fabia130vRS 2098]

These are the calculations on 60T 64P Pinion and 72T 64P Spur. I have two tire options.

3s speed calculation with 58mm Foam Tires /// 63mm Rubber Threaded TIres

58mm3s >> 155.9 KM/H /// 96.9 MPH

 

63mm3s 169.4 KM/H /// 105.3 MPH

 

2s calculations 58 mm /// 63 mm

58 mm 104 KM/H /// 64.6 MPH

63 mm 112.9 KM/H /// 70.2 MPH

[Fabia130vRS 2098]

sorry double post, bug in api.

 

[Fabia130vRS 2098]

I guess the top speed in this video was 70-80kmh on 2s. this was still the tble01 and tblm 8T 5700kv motor.

 

[Fabia130vRS 2098]

Some carbon ordered also.

[Fabia130vRS 2098]

Call me crazy guys, but I tried to talk OPEN AI's - ChatGPT about RC cars and my gearing.

I tried to find out the impact of 64P gearing. (the open ai system is now on overload and can't log in atm to find out)

As I understand, for example this calculation...

Internal gears are mostly 48P or so ? cant be 64P right?

SO how is this accurate regarding 64P gearing... maybe I have understood it wrong, but in diameter a 50T 48P spur is wider in than a 50T 64P spur?

Should affect top speed ?

[Fabia130vRS 2098]

Some upgrades were installed today.

Aluminum steering 54235 + 54261 and motor mount 54223.

I think this steering upgrade is crucial. 

 

While taking apart the gearbox to clean, check and lube. I notice the last crash I had while making speed runs was more hefty than I thought.

The plastic chassis did bend quite good, I used a torch lighter to heat and bend it back a bit, also the lowest screw that connects the motor plate and gearbox housing, is really bend also.

 

The steering upgrade comes with ball bearings, also the carbon link comes with micro flange ball bearings, nice machinery. I sealed the carbon with cement.

Tamiya TRF418 Carbon reinforced uprights were also installed for a more rigid feeling.

 

Used will be a 72T 64P spur and a 60T 64P Pinion. Fits in mm's, the motor screws would be better flatter for 1-1,5mm.

 

Waiting for more Tamiya hop-ups like motor mount carbon plate, carbon front bumper plate, rear damper stay carbon, carbon chassis stiffeners and spur mount.

Also, I ordered a Carson Dragster XXS ESC for the speed run. Will keep the china esc as reserve.

The carson has a 3S 12T motor limit at, 3800kv. Close enough to what I need, 4300kv 10T on 3S. 

 

 

 

 

 

[Simon998 36]

Nice build, good luck witht eh speed run! Are you doing the runs on rubber tyres? Most I see are done using foams

[Fabia130vRS 2098]

23 hours ago, Simon998 said:

Nice build, good luck witht eh speed run! Are you doing the runs on rubber tyres? Most I see are done using foams

The rubber tires I have now on the pictures, they were used at 103kmh. These tires are really hard and do not baloon much

I have foam tires but would like to try with new ones. 

 

More upgrades today.

Carbon Motor mount plate 54259 and carbon rear damper stay 54258.

Completed with a sticker

 

I noticed today, the steering with carbon reinforced uprights is satisfyingly stiff. 

 

The body also arrived, I like how it replicates the Honda Civic, as this FF03 was a Honda Civic Jaz kit.

 

[Fabia130vRS 2098]

Also... I bought a new motor for the speed run, which I have intentions putting into my Yokomo BD7 sooner or later.

 

A Muchmore Fleta ZX 13,5T zero timing, it is used and a bargain. 15€ for a 80€ motor. Who would not?

This motor has 13,5T and remarkably 4300kv, with the hop up titanium rotor, which is a few grams lighter, it may produce up to 4900kV.

Amazing.

edit: just did more research, this is the V1 version of the Fleta. Stock only 3120kV, makes a total top speed of 122kmh, but still I am confident about it.

I have also a trackstar 13,5T V2 thats only rated at 2543kV

[Fabia130vRS 2098]

These tires will be used. Rain / Asphalt tires

 

[Fabia130vRS 2098]

Waiting just for the motor.

Connected the electronics to test the steering. WOW. The upgrades like steering arms, carbon steering link with ballbearings and trf418 carbon reinforced uprights really do make a difference.

Added a capacitor to eliminate servo glitch.

https://imgur.com/SijqfM2