why cant we have f1 downforce on road cars

[Just_a_fan]

Excessively high downforce levels on road cars makes as much sense as road tyres on a Formula 1 car...

[mertol]

High downforce would require a stiff suspension to support it which would make it uncomfortable.
High downforce would make it harder to balance the car at high speeds as small differences in ride height, rake and tire pressures would make a big(er) difference. It would require engineers to maintain it.

[J.A.W.]

Road surface & ramp angle clearance practibility may be legally sanctioned via a set minimum road/underbody clearance.
Race machines can run much lower to utilise certain ground-effect advantages.. perhaps forbidden to road legal cars?

The issue of pedestrian crash safety regulations for road machines may limit the size,shape & placement of aero-devices too.

[riff_raff]

Where would you find public roads smooth enough to operate a car with very limited ground clearance and that is very sensitive to changes in ride height/pitch/roll?

Many high performance cars actually have active devices (rear spoilers) that maintain a stable aero condition at higher speeds. Just enough downforce to keep the car traveling in a straight line.

[Erunanethiel]

Needing a stiffer suspension is irrelevant since like the ln system in p1, you can stiffin it up for track use. Also ride height required for street doesnt matter because it can be adjusted at the push of a button. P1 is not even road legal due to headlamp heights in the lowest setting. And drag still is no problem with the help of drs.


I still cant see why not more

[Just_a_fan]

OK, let's ask the question in another way: why do road cars need massive downforce?

[bhall II]

Everyone knows this: the bigger the downforce, the bigger the schwanz.

[J.A.W.]

Everyone knows this: the bigger the downforce, the bigger the schwanz.

Schwanz?
Did you mean Schwantz, the notable Suzuki GP 500 champion?
& that road cars really need D-F to attempt to compete with bikes?

Or did you intend a 'Spaceballs' reference.. as in Dark Helmet's classic remark.. "my schwartz.. is as big as yours!" L.O.L...

[J.A.W.]

Where would you find public roads smooth enough to operate a car with very limited ground clearance and that is very sensitive to changes in ride height/pitch/roll?

There are some.. such as the Mt Panorama circuit at Bathurst,
..which is a (2-way!) - public 'scenic' road.. for most of the year, when not being used as a race track..

[dodds_turbo]

OK, let's ask the question in another way: why do road cars need massive downforce?

Good question. The answer is simple: THEY DON'T. =D>

[Tim.Wright]

Downforce will make the cars more stable and therefore safer in typical highway driving conditions, but at the expense of practically everything else. Fuel economy, acceleration performance, ride comfort, packaging space, interior room, luggage space, cooling requirements, pedestrian safety. Every system would need to be compromised from a layout/packing point of view to hit your aero targets and for luxury cars these compromises aren't acceptable.

Additionally, to get F1 performance from the downforce its not the raw Cz you need but its more important to have a high downforce:weightforce ratio. For F1 this is in the range of 1-2 which is why they can corner at 3+G with tyres that have a coefficient of friction of around 1.6.

To get the same performance from your McLaren P1 you need 1.5 - 2.0 TONS of downforce at cornering speeds.

[turbof1]

Like Tim said, you'd need to compromise everything for the downforce and saving weight. We'd basically be driving around with le mans cars.

It would multiply car cost 100x to 1000x the price of your normal city car. Maintenance on your car would be every 1000km, if not less.

Your engine would need to put out enough horsepower to get up to speeds quick enough to make the downforce relevant. Those speeds require special brakes that require extensive knowledge and experience to operate.

You also would have to remove max speeds everywhere to make any relevant use of the downforce. Next to the truly devastating traffic hazards this poses, the road asphalt is not up to this. Governments will need to replace the tarmac everywhere with one up to the job, and will have to frequently patch up everywhere. It would pose too a 100x multiplier on road costs.

Finally, your average joe is not a racer. He will not be able to cope with the G-forces. F1 drivers might come out of F1 cars without a sweat, let's not make any mistake that they spend hours every day in the gym to have a body able to cope with the forces.

Rather when looking at cars like laferrari and the 918, you want to look at mechanical grip then aerodynamical grip. High grip tyres combined with a very good weight distribution and a low centre of gravity will apply always no matter the speed. We are looking at cars also who have more then enough downforce at higher speeds to keep the car stable at turning high speed corners.

[rjsa]

Why is this still going on?

What happened to this forum? Is this really worth more than off topic chat, at best?

Are these all a bunch of 12 YOs aiming for short sleeved shirts and pocket protectors?

[bhall II]

Schwanz?

Schwanz.

Are these all a bunch of 12 YOs aiming for short sleeved shirts and pocket protectors?

In some sense, it's a little interesting, if only for the absurdity of the the relevant thought experiments.

For example, based on (very) rough calculations born from Kansas tedium, a 1,500kg car with enough downforce to genuinely match F1-level performance would encounter so much drag that it would need about 680bhp to equal the ET of a BMW F80 M3 (425bhp, 1.595kg) over a 1,000m run. For the last 600m or so, the BMW would be faster.

To reach the BMW's reported top speed (174mph), the mythical road beast would need somewhere in the region of 1,532bhp, but the M3 would still get there quicker (~3s).

[Erunanethiel]

I think the main reason for that little downforce is because you cant get a big splitter up front in the car due to safety reasons.
And without downforce on the front, you can not have much downforce at the rear without unsettling the cars balance.

About there not being any roads where you can exploid the limits with downforce, p1 is allready too much for road, but thats not the point of a hypercar. Plus you can allways have a trackday with it.

For those who says downforce increasing drag, it is irrelevant for cars like p1 since you dont have to have the spoiler etc up all the time, a push of a button solves that problem. The same goes for the need of hardening the suspension, because they are adjustable on the push of a button, you harden when you are going to drive it fast or take it to the track.