Limitless How to reduce caster to improve steering?

[kaladeth]

Goal is to reduce (front) caster from stock 20 degrees, to 16 degrees, to improve steering on the track.

@Overkill

Some options:

1. Trim the stock arms on the front hinge pin area by about 5 mm, so the arms (and pillow ball) can be moved forward 5 mm.

AR330215 stock

AR330215 trimmed

2. Get a longer suspension mount that moves the rear hinge pin location outwards by about 2 mm on each side. This will swing the pillow ball about 5 mm forward. Does anyone know where to find this part for sale, or if there is an STL file, or if someone sells a 3D printed one?

I will try to modify this one:
https://cults3d.com/en/3d-model/tool/arrma-composite-suspension-mount-front-upper

AR330379 Font-Rear Suspension Hanger is second from the top:

Extended

3. Design and 3D print a custom front suspension arm that has the same hinge pin geometry, but sweeps the pillow ball forward by 5 mm.

One of the guys at the track did this, will check in with him for more info.

Are there any other options out there?

 

[CosmoM3]

You'll have to make your own.

Have you tried messing with the ackerman first?

 

[Garcbomber]

Typhon TLR towers, ackerman, and hinge pin/suspension blocks will provide unlimited adjustments. Just cut the tower down and create the geometry hole for the shock mount.

 

[Dan B.]

I would just file down each upper arm in equal measure at the hinge pin holes. Then you can add the shims on the other side to compensate,

 

[kaladeth]

Trying this out. I went with 8 mm longer.

 

[kaladeth]

I had to dial it down from 8 mm to 4 mm because going too wide interferes with the steering bellcrank. I got around 3-4 degrees less caster (not much). Was able to take the car out for a test run, using the same old tires as before. The steering feels better but hard to see if it has an impact on the track - will have to see on the next practice day.

Link to the STL for those interested:
https://www.thingiverse.com/thing:6532459

@CosmoM3 @Garcbomber - I will certainly read up on it (ackerman). Any quick pointers for me?

 

[CosmoM3]

@CosmoM3 - I will certainly read up on it. Any quick pointers for me?

If you need more steering, you could go down a hole (or two, preference really) on your ackerman bar (the silver bar where your steering tie rods are connect to). That's what they're for: lower holes = the inner wheel of the car will turn more during cornering.

 

[kaladeth]

Got it thank you! I put in a beefier steering rack. Will try the different holes. Right now it is setup connected to the “stock” position which on the below photo will be the lowest of the three.

 

[kaladeth]

Is it possible to increase steering response further by moving the top shock mount to the outer hole to make the shock more upright?

 

[Garcbomber]

Is it possible to increase steering response further by moving the top shock mount to the outer hole to make the shock more upright?

Negative on the shock angle (results in negligible change in spring rate/rebound), but if you replace those brass/bronze bushings with bearings that will most certainly help. IIRC they're 6x10x3mm

 

[Surchaufeur]

i feel like the onroad cars have so much caster for nothing. at full lock you only have the edge of the tire touching the ground. causes premature wear and funky steering like understeer. i printed the part in petg and see how it drives before i change the fluids

 

[kaladeth]

@Surchaufeur - Thanks and good luck! Looking forward to the report.