Setup Guide

BASELINE SETUP

This is a good all-round baseline for 1/8 GT on rubber tyres at St Anne's Park. It's conservative, forgiving, and a solid starting point. Once you're comfortable, experiment one change at a time — always write down what you changed so you can go back if it gets worse.

Setting	Front	Rear
Camber	-1.5°	-1.5°
Toe	0° to 0.5° out	2° in
Ride Height	6mm	7mm
Droop	8mm	10mm
Caster	10–12°	—
Spring Rate	Medium	Medium-Soft
Shock Oil	400–450cst	350–400cst
Diff (Front)	30,000–50,000wt	—
Diff (Rear)	—	5,000–7,000wt
Diff (Centre)	—	15,000–20,000wt

💡 Rule of Thumb

Always make one change at a time, test for a full run, then decide if it's better or worse before making another change. Changing multiple things at once makes it impossible to know what worked.

SUSPENSION GEOMETRY

Suspension geometry controls how the tyres sit on the track surface and how the car handles through corners. For rubber tyres, settings are less aggressive than foam — you want the tyre to roll cleanly without excessive wear.

CAMBER

The angle of the tyre relative to vertical, viewed from the front. Negative camber leans the top of the tyre in towards the car.

Baseline: -1.5° all round

More negative = more corner grip, more tyre wear. Start at -1.5° and adjust from there.

TOE

The direction the front of the tyre points relative to straight ahead. Toe-in = pointing inward. Toe-out = pointing outward.

Front: 0–0.5° out · Rear: 2° in

Rear toe-in gives stability. Too much front toe-out causes darty steering.

CASTER

The forward lean of the front steering axis. Higher caster gives more straight-line stability and self-centring, but can reduce steering response.

Baseline: 10–12°

Most 1/8 chassis have adjustable caster via suspension inserts.

RIDE HEIGHT

The gap between the chassis and the ground, measured with the car sitting on its tyres under its own weight.

Front: 6mm · Rear: 7mm

Slightly higher at rear helps rear traction. Measure at the same point every time.

What Does Each Setting Do?

Change	Effect on Handling
More negative camber (front)	More mid-corner front grip, but can make the car feel nervous on turn-in. More tyre wear on inner edge.
More front toe-out	More responsive steering, but less stable on straights. Can cause the car to dart around.
More rear toe-in	More rear stability — car tracks straighter. Too much makes it understeer (push wide).
Lower ride height	Lower centre of gravity — less roll, sharper handling. But risks grounding on bumps.
More caster	Better straight-line stability and self-centring, but steering feels heavier.

SHOCKS & SPRINGS

Shock absorbers control how the car moves over bumps and during body roll in corners. Getting shocks right is one of the biggest areas for performance gains — and it's very track-specific.

Shock Oil Weight

Thicker oil (higher number) = stiffer, slower shock response. Thinner oil = softer, faster response. For a smooth track like St Anne's, start with the baseline weights and adjust based on how the car feels.

Too Stiff (oil too thick)

Car feels harsh over bumps
Loses traction on bumpy sections
Can feel like the car is "skipping"
Fix: Drop oil weight by 50cst

Too Soft (oil too thin)

Excessive body roll in corners
Car feels wallowy, unstable
Poor traction under hard acceleration
Fix: Increase oil weight by 50cst

Springs

Spring rate affects how much the car compresses under load. Stiffer springs = less body roll, but less traction over bumps. Softer springs = more traction, but more body roll in corners. For rubber tyres at St Anne's, medium springs all round is a good start. Use slightly softer rears for more rear traction if the car is spinning out.

Droop

Droop is how far the suspension drops when the wheel hangs freely (car on a stand). More droop = more suspension travel available when the wheel drops into a dip. The baseline of 8mm front and 10mm rear suits most conditions at St Anne's.

DIFFERENTIALS

Differentials control how power is split between the wheels on each axle. Heavier diff fluid = locked diff (more stable, less nimble). Lighter fluid = open diff (more nimble, less stable).

Front Diff

A heavy front diff (30,000–50,000wt) makes the front end feel stable and planted on corner entry. A lighter front diff makes the car more agile but can cause understeer on corner exit.

Rear Diff

The rear diff has the most effect on traction and corner exit. Start at 5,000–7,000wt. If the car spins out on corner exit, try heavier oil (up to 10,000wt). If the car understeers, go lighter.

Centre Diff

The centre diff splits power between front and rear axles. Heavier oil transfers more power to the rear (more rear traction, more oversteer). Lighter oil transfers more to the front (more understeer but better high-speed stability). 15,000–20,000wt is a good starting point.

💡 Diff Tip

Diff changes have a big effect. Start with the rear diff if the car is spinning out, and the front diff if the car is pushing wide. Change one diff at a time.

COMMON HANDLING PROBLEMS

Problem	Likely Cause & Fix
Understeer (pushes wide)	Reduce rear toe-in / soften rear springs / add more front camber / lighten centre diff
Oversteer (spins out)	Add rear toe-in / stiffen rear springs / reduce front camber / heavier rear diff
Nervous on straights	Reduce front toe-out / increase caster / heavier front diff
Twitchy on turn-in	Reduce front camber / increase front toe-in slightly / stiffen front shocks
Poor traction on exit	Soften rear springs / reduce rear camber / lighter rear diff
Bouncing over bumps	Reduce shock oil weight / soften springs