The road car aero myth

[Petrus]

Much misquoted and misunderstood; aero has heavy influence on the TdF riders even so PÍNG I´d say.

Have a look and listen carefully at this video https://www.youtube.com/watch?v=abheF2qkenE

For those with less tme or attention span, rewatch/relisten from 5:30.

Now, the Mk3 MR2 starts out at about 1000-1100 and I have it down to well under 900. Say 50 kg aero force pushing down gives 5% extra traction at no extra centrifugal force. That can be more speed or more safety margin. By all means choose to ignore that, but unless your name is Jeremy Clarkson don´t repeat the myth.

By all means, it is good fun to have a laugh about me weight OCD; Í do.
Nonetheless it add up to more safety margins at every angle and side. In the perspective of aero too.

Fact: OEM the car has the aero designed for fuel efficiency ONLY.
The FL grew a optional chin lip for noticeable added stability on highways; it reduces lift under the front enough to notice at 90-100 km/h.
Ponder about that; a 3 cm high strip under the central bit of the bumper apron...

Again, do with it whatever you like but don´t deny it:   TdF teams invest in more slippery sócks even, heck the governing body has set up rúles about!  About the aero of cycling sócks ffs. What more proof do you want?!

[Beachbum957]

There are always an aero effect at almost any speed. The only question is how much.  Since aero forces go up by the square of the velocity, the effects at higher speed may be very significant, while the effects at lower speeds may not be very significant.  The problem is both downforce and drag increase by the square of the velocity. So the decision is on how to compromise.

Most street cars focus on reducing drag to improve economy while keeping lift to a minimum.

Not a myth, a decision.

[Dev]

Fact: OEM the car has the aero designed for fuel efficiency ONLY.

This is where your argument falls apart. 
 Sure you can make an argument that at much higher speeds aero is needed on any car but for most cars unless there is a design error most cars should be able to handle most road situations where you are not driving at racetrack speeds that are not safe when sharing the road.
 There is nothing wrong with the design of this car for 99% of road going drivers that want to enjoy a spirited drive. Toyota did an excellent job with making sure the car doesn't lift for its intended purpose which is primarily a street car. If you look a todays super cars they go out of their way with better designs so they don't use ugly appendages and instead work it into the design taking a multitude of factors like fuel efficiency  as one of the many criteria but I would imagine safety would be number one otherwise our car would look like a Prius.
 
There are some cars in the past where they share the same engine with another car but they will place speed limiters in the ECU because the car is aero limited which is for safety. The manufactures work this out and if there is a wide spread problem you hear about it and then it gets rectified.

 If you need a wing on your car to make you feel safe that is fine but for most with a well sorted car they do not and in many ways it can be aesthetically ugly. If this car was aero limited for the speeds I drive and the only way to fix it is with a BFW I would instead sell my car and get something better.

[MRSwede]

Isn't there a easy solution for this !
Add more weight. The car goes slower and it need higher speed before it lifts. Safe 

[Petrus]

Isn't there a easy solution for this !
Add more weight. The car goes slower and it need higher speed before it lifts. Safe 

It will go off the road quicker, have a longer stopping distance and make a bigger bang when that is not short enough...

Aero is one of the few areas where there is something for near nothing on the MR2 because of the OEM focus on slipperyness and real world speed limits; a bit of extra drag is of little consequence but the gains sure are positive.

Went out for lunch with c-company and was agaín impressed about how much difference the little flap behind the seats makes.

[MRSwede]

Well a BFW is not always the key to success

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[Dev]

 Not always.

 

[Petrus]

Well a BFW is not always the key to success

Should have been bigger no?!  ;-)

The TRD Sportivo kit also gave a bit of rake btw.
Mr.T knew very well what the lift reduction vs drag was.
A good example of OEM priorities for the average user and the more dedicated driver.

[Beachbum957]

A BFW hung out over the back changes the center of pressure, and not necessarily in a good way.  But who cares about science and fluid dynamics. It makes the car look like a racer!

[Petrus]

A BFW hung out over the back changes the center of pressure, and not necessarily in a good way.

So have it on the rear axle and balance it with front aero.
Or not, if you like it slippery for the extra mileage and/or extra top speed.
Í don´t mind the mileage; it is better than SUVs anyway. Nor do I drive over 160 all thát much.
I dó like the extra margin of traction through corners.
Take It Or Leave It.

Point is that the myth is that aero does not work on road cars. The grain of truth is that the same aero forces have less effect the heavier the car is. It does wórk though.
The proof is there to see for whom wants to see it:
- For one manufacturers spend fortunes in the windtunnel for slippery cars at average, lów, speeds, proving the point; if it works thát way, it works ány way see.
- Secondly Kyle says it doés work on any vehicle from any speed; just less on lardy ones, obviously. And, surprise; the MR2 Spyder is light. Tatááá.

Oh and as Kyle says, the bigger the aero stuff, the quicker it adds up seriously: Go BIG or go fast and fast gets you tickets/point off your license so, again, tatááá.

[Petrus]

Here a nice FL photo. It shows the rubber lip under the bumper shroud. See what a diminuative thingamy it is?
Toyota did not fit it under the PFL for more slipperyness.
It does reduce lift under the front and improves stability from 80 km/h.



p.s. @Snelbaard  thanks for sharing this photo. It also TOTALLY sells your FMB for the PFL!!