A quiz for people

[RedDevil]

Mind you, their unit definition of human-horse power equates to 300 Watt (instead of 745,7 Watt for equine-horse power).
So the steering committee should be pootling along in a car with only roughly 600 HP or 450 kW.

I don't know what it is in hobby-horse power but it should do. Hippity hop.

[Fat Charlie]

Originally Posted by AeroMcAeroFace

Yes, I do know that that a steering committee doesn't actually deal with car steering but what sort of road car needs 1500 horsepower?

One that weighs too much.

[Snax]

Originally Posted by JulianEdgar

(1) Downforce
(2) Neither lift nor downforce
(3) A small amount of lift
(4) A lot of lift

Just putting down the number that corresponds with your guess would be good.

Before reading further in the thread, guessing #2, and potentially #1.

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Post read: Having no idea that they left the bottom basically flat, makes sense all around to me.

The Cambridge car crashing also makes a lot of sense. A crosswind against that profile at speed clearly lifted the rear while creating significant yaw force.

I think one way to address that issue without actually changing the form of the car would be to have 4-wheel steering, allowing the car to crab down the road dynamically with wind gusts. That would obviously only work to a point and is probably completely impractical in terms of lane keeping though.

[aerohead]

Originally Posted by Snax

Before reading further in the thread, guessing #2, and potentially #1.

----------
Post read: Having no idea that they left the bottom basically flat, makes sense all around to me.

The Cambridge car crashing also makes a lot of sense. A crosswind against that profile at speed clearly lifted the rear while creating significant yaw force.

I think one way to address that issue without actually changing the form of the car would be to have 4-wheel steering, allowing the car to crab down the road dynamically with wind gusts. That would obviously only work to a point and is probably completely impractical in terms of lane keeping though.

As a full-scale vehicle, the additional mass would be beneficial.
Ford's 1985 Probe-V concept of Cd 0.137 incorporated a small dorsal appendage behind the backlight to address center-of-pressure issues, and Ford claimed no problems with directional stability at speed.
NASCAR and Bonneville cars which become airborne typically lose traction and get sideways, becoming a crude airfoil in the process.
1991 Corvettes require 221-mph. Racing Beat's 1992 RX-7 Bonneville needed over 240-mph to get ten-feet into the air. The crash of the HONDATA was sort of the same story.

[freebeard]

Snax — Cars that have four-wheel steering switch from turning to crabbing at about 25 mph. IIRC of course,

[AeroMcAeroFace]

Originally Posted by Snax

I think one way to address that issue without actually changing the form of the car would be to have 4-wheel steering, allowing the car to crab down the road dynamically with wind gusts. That would obviously only work to a point and is probably completely impractical in terms of lane keeping though.

would that be attempting to move the car into the wind and being blown back? or pointing the car into the relative wind to be head on?

[Fat Charlie]

Pointing the car relative to the wind, while the wheels stay relative to the road.

https://www.youtube.com/watch?v=9tyc9Imjaqs

[JulianEdgar]

Originally Posted by Fat Charlie

Pointing the car relative to the wind, while the wheels stay relative to the road.

Yes I, for one, think that this could work with really fast data gathering (relative wind direction is used in yacht racing) and really quick mechanical steering.

[Fat Charlie]

It'll have to wait until everything's autonomous. Texty McSwervalot can't handle driving a car that isn't facing the same way it's going.

[redpoint5]

Originally Posted by Fat Charlie

Pointing the car relative to the wind, while the wheels stay relative to the road.

Do the wheels pivot to face direction of travel? I always thought they just scrubbed upon touchdown.