build thread Building a TT-02 Audi Quattro A2 for rally

[Rvl 2 14]

1 minute ago, Nesrak said:

Alright I ordered the yeah racing steel TT-02 universals for front and rear. I bought the dust cover and a 66t spur. I got some body post extenders to fix my wrongly cut ones. Finally I also got some heatsinks and the low friction suspension balls for the front suspension just because they were really cheap. I'll start making some videos soon!

I found the YR diff cups a little short and replaced with Tamiya ones , the Tamiya universals are 39mm , YR are 38mm. If you have too much drop in the dampers the diff cups come flying out.

[Nesrak 112]

26 minutes ago, Rvl 2 said:

I found the YR diff cups a little short and replaced with Tamiya ones , the Tamiya universals are 39mm , YR are 38mm. If you have too much drop in the dampers the diff cups come flying out.

What is your ride height? I'm mostly just getting them for less rubbing and improved steering angle.

[Rvl 2 14]

2 hours ago, Nesrak said:

What is your ride height? I'm mostly just getting them for less rubbing and improved steering angle.

I think it was 7-8mm (it was higher but too much body roll in tight corners)but the rally race was cancelled this week(only 2 people)and I switched it over to truck but the body didn’t arrive in time

These help a lot , I have them on my 2 tt02sr but they aren’t allowed in our rally races https://www.thercracer.com/2018/08/tamiya-42319-42320-lightweight-cardan.html but I switched one to the steel center instead of the aluminum 

[Nesrak 112]

9 hours ago, Rvl 2 said:

These help a lot , I have them on my 2 tt02sr but they aren’t allowed in our rally races https://www.thercracer.com/2018/08/tamiya-42319-42320-lightweight-cardan.html but I switched one to the steel center instead of the aluminum 

Thank I'll try those out if the yeah racing ones are no good. They are very expensive though...

[Nesrak 112]

Made a short video of my TT-02. It just goes over the mods and upgrades really quickly and then shows some running footage on gravel. I'll start making a TT-02 series for mods and upgrades later on.

https://youtu.be/h2dwIrFTg6w

[Nesrak 112]

Some of the parts arrived! Put them on but holy I didn't expect much of a difference from the low friction suspension balls but they actually make a difference. I haven't driven with them yet but they feel super smooth.

Also, apparently I had the shock springs on the wrong way with soft in the front and stiff in the back but it's supposed to be the other way around. No wonder it would roll over sometimes 😅

[Nesrak 112]

On 11/4/2022 at 9:50 PM, Oosto said:

Nice work.  I use 55mm 3Racing aluminium shocks on my TT02 rally (with upper mounting holes on suspension arms) and get 20mm ride height which I find is good enough for most of my off road adventures 😊  I suggest getting the Tamiya or Yeah Racing aluminium rear hubs (with 3 degree toe in) and trimming the lower shaft of the front steering hubs (note: there is great video from Mark Bryan RC on YouTube that shows you how to do this) as both of these mods will help you maximise ground clearance without fowling the drive shafts.  I also highly recommend using the Tamiya TT02 dust cover or one from Kamtec (which I use) to protect the electronics and stop gravel from jamming up the steering and centre drive shaft.  Happy rallying!

So I've been looking for the video and I don't know what you meant by "shaft". I know they're are the little flaps and the steering link but I don't know what shaft you mean.

[Oosto 82]

It’s the part of the upright that goes into the ball joint of the lower suspension arm.  Please refer to this video: 

 

[Nesrak 112]

12 hours ago, Oosto said:

It’s the part of the upright that goes into the ball joint of the lower suspension arm.  Please refer to this video: 

 

Ah yeah I followed that video already lol. Great mods for the TT-02 in that video!

[Nesrak 112]

To all who said YR universals worked with the tt-02 without new diff cups, you are wrong. I tried fitting them and not matter what they are just too long and I checked the instructions and it says "steel gear box joint (not included)" on it meaning I do need to get some cups for it to work... 😑

 

 

[Oosto 82]

the part of the upright that goes into the ball joint of the lower suspension arm.  Please refer to this

 

Please note that there are two models - one that is designed to use with the kit standard drive cups; and the one which you just bought which requires smaller cup drives.

[Nesrak 112]

Ok so it's been awhile since I posted because I've been experimenting with stuff...

First thing I did was install the universals and diff cups which got me from 24mm of ride height to 25 but also got me much more steering angle

Then I took the short eyelets off of the shocks and put on the long eyelets taking them from around 60mm to about 67mm long. Then I mounted them in the bottom holes on the lower suspension arms. This gave about 4mm more travel making it smoother. Because there is more travel now I put the hard springs on the front (blue) and the medium springs on the rear (yellow).

 

[Nesrak 112]

Ok so now onto some stuff, I learned that the screws used in the shocks I bought are the same size as the ones used to hold the body posts onto the shocks tower... (Can you see where I'm going with this...?) And I ended figuring out that with the long eyelets on the bottom holes on the lower arms that the shock fits perfectly in the body post hole. I don't know if it's safe to try/use but I just thought I would post about it here. It allows for a more vertical shock position as seen in this photo. (modded on the left regular on the right)

[Nesrak 112]

Ok so some more experimenting and it turns out with the shocks I have it actually limits the the ride height to around ~25mm so you'll need longer shocks to do this. It seems stable though so it could be a good opportunity for a Long Damper spec TT-02. I'll see about testing that out if others don't want to.

[Nesrak 112]

If you did the short eyelets on the top holes on the lower suspension arms then it would probably work though. If I end up getting to around 27mm ride height I'll try it with the long eyelets on the top hole with the body post suspension mod. (Idk if anyone has thought of this mod yet so I will call it the body post suspension mod )

[Nesrak 112]

Maybe I can turn this TT-02 into the:

TT-02 LDRS

TT-02 Long Damper Rally Spec

😁

[Nesrak 112]

Ok so I'm following this TT-02 tuning guide

https://www.thercracer.com/2014/08/tamiya-tt02-guide-mods-tuning-and-tips.html?m=0

And I got some 500k weight diff oil.

First I had to take apart the front bulkhead to get to the diff. Then after that I pulled the diff out and started wiping it down. That didn't really do much so I had to manually scrape off the old grease which took awhile...

[Nesrak 112]

After that I started to add the gears in and then add some grease then add some gears etc. The grease was so thick though so I ended up just filling it with some grease, putting the drive cups in, spinning them, then adding more grease until it was filled.

After I filled it up I cross screwed it together and put the bearing and drive cups in giving us the final product:

After that all that was left to do was stick it back in the car, grease the driveshaft gear, and then reassemble the front bulkhead!

[Nesrak 112]

The guide said that generally you want the front differential to be much stiffer than the rear so all of this was only done to the front diff. The rear is still using the regular Tamiya grease.

Also some rally blocks and the Tamiya steering set has been purchased. The dust cover should arrive this week as well so pretty soon this will be a fully tuned rally car!

[GreatDane 69]

I must say, a great and informativ tread c'',)

[Nesrak 112]

The new rally blocks tires have arrived! I opted for the softer compound because it also came with tire inserts and people said it worked well.

[Nesrak 112]

Out with the old,

[Nesrak 112]

And in with the new!

[Nesrak 112]

Now the car sits at just above an inch or around 25mm ride height under load and 26-27mm without load!

With a few mods and parts this thing should easily get 27mm ride height but I will probably adjust down stops after bringing it back down to 25mm but have better suspension.

[Nesrak 112]

I have a question about suspension, do I want it to be stiffer so ride height is higher? Or do I want it to be softer to have a smoother rebound but with lower ride height?