TT-02 Handling Modifications by Rich

Hey everyone - OK so we have arrived at a point with this car where the handling really needs to be addressed.

 

Yes I have had fun building it and speeding it up, but the truth is on 2s it is awesome fun but slightly twitchy (I am used to it now). On 3s however it simply goes sideways - I have had a few large crashes trying to do speed runs for fun. It will not go in a straight line for more than about half a second on full throttle.

 

Here she is with a slightly battered body from all the rolling…

So now to make this thing a stable, 50+mph basher.

 

Besides wanting to keep the car in one piece, I really want to try to make it as fun and user friendly on 3s as it is on 2s. The motor is only getting lukewarm even with the gearing up I have done, and I can always run a motor fan from my receiver if I need it.

 

Then there is the added incentive that if it can crack 50mph from a blip of full throttle then I’m hoping for a bit more speed if I can get the car setup so I can pin the throttle properly.

 

Handling Mod List

 

• First things first. The stock TT-02 tyres are simply not up to the job. They have no foam inserts meaning that they in effect balloon at high RPM and collapse in the middle and as a result you get very little tyre contact on the road. I can physically see the results from 2s bashing where the tires are nearly bald on the inner and outer edges and look brand new still down the middle.

 

I plan to upgrade them to Tamiya semi slicks (part ref: HC-50810) with foam inserts, on TE37 wheels with a nice offset and in bronze (part ref: HPI-3848). This should ensure a nice even contact on the surface with plenty of grip.

In the car pictures you may notice that I currently have foam tyres on there - this is just for fun testing as they are super cheap but will wear out very quickly - they are part ref: SCH-J13273.

 

• Ok so tires sorted, next thing to address is the steering. It is quite a well known thing in Tamiya circles that the TT-02 steering is *choose word carefully*...a bit rubbish. I find that I need to do steering trim adjustments constantly as there is a crazy amount of play in the components.

 

Don’t be too hard on this car though - remember it is built to do 20mph, and not the abuse we are giving it.

 

The parts I need are not cheap. I intend to replace basically the whole steering rack and arms, replacing them with far more accurate turnbuckle items.

This is the full replacement set. It upgrades everything right down to the steering servo arm/saver - part ref: HC-54752. If you do not wish to buy the above kit, you could go for part ref: HC-54965 which is a cheaper kit and will still provide a massive improvement but does not include quite as many parts.

 

• Shock absorption is key to a car's handling, and the stock TT-02 shocks are very cheap and not very cheerful.

They are not at all solidly built and they kind of just clip together. There is no oil in the shock, and the rebound speed is instantaneous meaning the car bounces around all over the place. These need upgrading ASAP.

Thankfully, we have a very nice upgraded replacement provided by Fastrax - part ref: FTTA014B. You will see several other components provided by this brand for the TT-02 and other Tamiya kits. I will be using 30wt shock oil.

 

• My final handling modification for the time being is the differentials. The standard TT-02 diffs are not oil filled and may well be not up to the job of 50mph+. This could be a large contributor to my crashes.

I will be upgrading both differentials to part ref: HC-54875. These should prove up to the job while being longer lasting due to reduced friction and metal spider gears.

Summary

 

I appreciate these mods will add up to a decent amount of money - probably as much or more than the chassis cost in the first place. I intend to do them one at a time rather than all at the same time in order to give as much insight to how much this car can be improved on a budget.

 

The first test will be on improved tyres and no other modifications.

 

I will keep you guys posted on any future speed runs with the mods in place. The main aim is to make the car usable. Also 55mph would be nice.

 

A final mention on the money side of it - lets just take a moment to remember that if we can make the humble TT-02 user friendly at this speed then it is sitting in the same bracket as an Armma Infraction 3s. Yes it is still a delicate Tamiya, but who cares.