Race Car Steering

[Peter Jones]

The fewer turns the heavier the steering will be.

With only one turn lock to lock you'd need to be Superman to park it.

Obviously the intent is to get the car to react quicker but there's a lot of trade offs.

Remember that the steering wheel works in both directions. Every bump, pothole, gutter, pensioner etc that you hit is transmitted back through the wheel. On a stock rack the sensation is geared down quite a lot so it's not too bad at the wheel.

With a quick rack you're not only reducing the movement required to turn the wheel you're also increasing the effect at the wheel of the road bumps.

So if you halve the number of turns lock to lock you DOUBLE the "road feel" back through the wheel. On a long drive the wheel will beat your arms to jelly.(Especially on a lowered car with stiff suspension)

Going from stock to 1 turn the ratio is probably something like 3.5 times.

The effect this has on the driver is very tiring , you'll be fighting the thing constantly. There will be no more steering with one hand while you're changing radio stations. One inch on the steering wheel now means you're under the front of the oncoming Kenworth.

For racing the goal is to not have to take your hands off the wheel for any corner of the track so some reduction form stock is required. If you reduce it too far though you loose the very fine control and are at risk of overdriving the car. There's a limit to how fast the car can accept input. On a stock car it's set up with a fair safety margin so that rapid input changes are not possible and the driver is not fatigued by road noise transmitted back up the column.

Motorkhanas are a special case, you do want to go very fast from lock to lock but they're usually held on loose surfaces. You're also only out the in the dust for 30 seconds at a time.

The sprint car example I mentioned earlier is also a special case, those guys are insane and there's no logic that can be applied to what they do.

To get down to one turn lock to lock you'd probably need to go to fully hydraulic steering which isn't practical for soooo many reasons but if you've got a bucket of money and you're considering a career as a sprint car driver I can give you a few tips on how to set it up.

Pete

[Spyda]

Driving a go-cart for more then 30min isnt easy. Your forarm is left a bit bigger and numb after it and hands red from griping the wheel.
Would be similar, true?

[Peter Jones]

Driving a go-cart for more then 30min isnt easy. Your forarm is left a bit bigger and numb after it and hands red from griping the wheel.
Would be similar, true?

Probably worse because you're going faster in a heavier car.

Pete

[Jarred]

pete you're a funny man.

go play playstation witha steering wheel and set up the wheel to have really small dead zones, this makes it quick to respond. and trust me, VERY difficult to drive!

I can see where you're going. maybe look for a "racing" (I use this term loosley) spec rack. I expect this would be V.expensive, and hard to find in OZ

[Preen59]

Probably worse because you're going faster in a heavier car.

Pete

The faster you go the lighter the steering becomes because the friction against the road begins to assist you as you turn instead of work against you.

The main reason karts have heavy steering is because they have 14deg (average, i have seen some with 1 caster angle, which is far greater than a road car.

But yes, because the car is substantially heavier, it would be worse. And the car with a closer to 1:1 steering ratio would be ridiculously nervous on the road. You'd be weaving your way up the street just trying to keep it straight!

[Water Boy]

Quick rack is crazy and guys at the Ring were saying take it off its ****... Great on a rally car though

[Manaz]

You'd be weaving your way up the street just trying to keep it straight!

I suspect a variable ratio rack would come in handy here (slower at dead centre, speeding up in ratio as you turn it towards full lock). Of course the drawback to this is that you end up losing feel at dead ahead.