Here's How Ground Effect Aero Devices Transformed The Way Race Cars Could Corner

Clive Chapman of Classic Team Lotus explains how the art of ground effect worked in Formula 1, and how it made cars corner so quickly it was deemed far too dangerous to allow

Cameron Tait

Updated: 31 Mar 2016

We don’t really hear much about ground effect any more, but jump back to the 1970s and it dominated motorsport.

So what exactly is it? Basically, air travelling over the top of the car is of a higher pressure than air travelling underneath it. Mimicking the principles of Bernoulli’s principle (which states that water travels faster in a constricted environment), teams would seal the exposed sides of the car with skirts, channelling the low pressure air beneath the car, which speeds up the underside airflow. This greatly increases downforce and decreases aerodynamic drag.

Ground effect was originally used by Chaparral in 1970 with the 2J. Looking more like a washing machine than a car, the 2J had its corners covered by small side skirts to seal the low-pressure air underneath the car.

The back of the car had two huge fans, taken from a military tank, that would pull air from underneath and throw it out the back, creating a low pressure area beneath the car that would suck it into the tarmac. It wasn’t entirely successful and was banned at the end of the season.

In Formula 1, Colin Chapman (father of Clive in the video above, and founder of Lotus Engineering LTD), introduced ground effect to the sport with the Lotus 78 in 1977. This was later improved the next year with the 79, and 1978 also saw the return of fan cars with Brabham’s BT46B.

Brabham’s fan car only competed in the 1978 Swedish Grand Prix, which it dominated. The cars were so quick they were ordered to run on full fuel tanks to not raise the suspicion of other teams. While it won the race, the fan was banned for the next round, which was followed by mandatory flat floors in 1983 due to the dangerous cornering speeds that ground effect cars could achieve.

Comments

Would this fit on my Honda?

Close enough

What happens if you do this to an R35?

You go unconscious at any 3rd+ gear bend

Regarding Chaparral : It wasn’t entirely successful and was banned at the end of the season. : Objection! It was ahead of its time’s competition, because of its technology (improved aerodynamics as you said). In fact, it made the other “big” competitors (like McLaren) so mad and bitter that their lobbying pressures banned the car, their main argument being “fans at the rear project objects like rocks to cars behind”, which was total BS. There was a very intersesting article online on the subject, but I can’t find it

The Chaparral 2J really wasn’t successful, but that was more due to it lacking reliability than it not having outright pace, which it had plenty of.

I do have a rather extensive post on the 2J in my archive.
Not sure if I can link it here though.

Aaaaaand this is what F1 should be doing for next year. Ground effect produce much less turbulence than the wings on current F1 cars so if they reduce the reliance on them, and put ground effect the cars can race each other closely which they haven’t done for years. Ground effect is one of the best innovations in F1 in my opinion.

They do use ground effect today. They just are allowed to only use flat underbody with a diffuser. This video was quite bad, because it didn’t even state that the thing which made the late 70s cars awesome was wing shaped sidepods. It also didn’t explain the benefit of those and why were they better.

The issue is the danger once any air gets under the car. Say youre mid corner and hit the curbing, suddenly youve lost all your down force and the car is sent flying into the closest wall. Also If say you were to go over a small bump at high speed and slightly nose up, youll suddenly get a larger amount of air going under the car, throwing it into the air like that one famous gif of the CLK GTR flipping into the air.

Don’t you mean Bernoulli’s Principle, not “principal?”

… how to rewrite history…

Do not forget the CD Panhard LM 64 :)

First car to use a “diffuser thing” and thus air lowering pressure effect underneath the car
A car able to reach more than 140mph with ….70bhp and 2 supercharged cylinder
Still LeMans efficientcy index holder !!

Okay this didn’t really explain why was it beneficial to shape the as much of the underbody as possible like a wing, which was the thing Chapman actually came up with. If it was only about Bernoullis principle, then a wing shaped sidepods shouldn’t be any more efficient than flat underbody. But it is, so there’s something missing in this explanation.

This video has inspired me to find out what exactly makes those sidepods great.
Starting with the Lotus 78 and working my way up might be a neat idea.

This part is very unclear:
“Mimicking the principles of Bernoulli’s principle (which states that water travels faster in a constricted environment)”
Let me reword it for you… “Using Bernoulli’s principle (which states that an increase in fluid speed is accompanied by a decrease in pressure)”