• Tech
    • Tech Category
      • Engine
      • Bottom End
      • Rods and Pistons
      • Head and Headwork
      • Cams and Valvetrain
      • Cooling and Heat Management
      • Intake
      • Headers and Exhaust
      • Rotary
      • Engine Management and Tuning
      • Drivetrain
      • Transmission
      • Clutch and Flywheel
      • Differential and Final Drive
      • Driveshaft and Axle
      • Axles
    • Tech Category
      • Suspension
      • Shocks and Coilovers
      • Springs
      • Swaybars
      • Arms and Links
      • Bushings
      • Steering
      • Geometry Correction
      • Suspension Setup and Tuning
      • Brakes
      • Wheels and Tires
      • Fueling
      • Forced Induction and NOS
      • Aerodynamics
    • Tech Cat
      • Electrical
      • Battery and Power Distribution
      • Electronics
      • Wiring
      • Electrical System Education and Troubleshooting
      • Lubrication
      • Interior and Controls
      • Exterior
      • Paint and Bodywork
      • Wraps and Film Protection
      • Exterior Care and Maintenance
      • Data Acquisition and Tuning
      • Fabrication and Safety
      • Tips and How-To
  • Projects
    • Make A-D
      • Acura
      • Integra (DC2)
      • NSX
      • CSF RSX (DC5)
      • BMW
      • E30 (SR20 Powered)
      • E36 323is
      • E36 M3 (Black)
      • E36 M3 (Silver)
      • E39 M5
      • E46 M3
      • E90 M3
      • E46 Racecar
      • Yost Auto E92 M3
      • Yost Auto F82 M4
      • Chevrolet
      • Camaro Gen5
      • Corvette Stingray (C7 Z51)
      • Corvette Stingray (C8 Z51)
      • GMC Canyon
      • Dodge
      • Viper GTS
    • Make E-I
      • Ford
      • E350 Tow Rig
      • F150 EcoBoost
      • Fiesta ST
      • Focus ST
      • Mustang 5.0 (Grey)
      • Mustang 5.0 (White)
      • Mustang S197 (Budget Track Car)
      • Mustang S550 GT
      • Honda
      • Civic EF Racecar
      • Civic Si (Coupe)
      • Civic Si (EP3)
      • Civic Si (Saloon)
      • EJ Civic
      • Polystrand CRX
      • S2000 (AP1)
      • S2000 (AP2)
      • Infiniti
      • G20 Racecar
      • G20 (P10 AWD Turbo)
      • G35
      • G37S
    • Make J-M
      • Isuzu
      • Vehicross
      • Lexus
      • ISF
      • SC300
      • Mazda
      • V8 RX7 (3rd Gen)
      • RX-7 (3rd Gen)
      • RX-7 Restomod (3rd Gen)
      • Skyactiv 3
      • Frankenmiata
      • Miatabusa
      • My Girlfriend’s Miata
      • Mitsubishi
      • EVO VIII
      • EVO IX
      • EVO X
      • CSF EVO X Racecar
      • Professional Awesome EVO VIII
    • Make N-P
      • Nissan
      • 200SX
      • 200SX SE-R
      • 240SX Land Speed Racer
      • 300ZXTT
      • 350Z
      • 350Z Drift Car
      • 370Z
      • GT-R (R33)
      • GT-R (R35)
      • GT-R (Team America BNR32)
      • LS S13
      • NX GTi-R
      • Pathfinder
      • S13 Drift/Grip Do-it-All Mega 240
      • Sentra SE-R
      • Sentra Spec V
      • Silvia
      • STurdteen Drift Car
      • Porsche
      • 991 GT3RS
      • Cayman (987)
      • Cayman T
      • Cayman GTS 4.0
    • Make S-Z
      • Scion
      • FR-S
      • Scion Tuner Challenge FR-S
      • TC
      • Subaru
      • Autocross BRZ
      • Legacy GT
      • STI (gen 2)
      • STI (gen 3)
      • WRX (GD)
      • WRX (VA)
      • Toyota
      • 4Runner
      • AE86 Corolla
      • GR Corolla
      • Starletabusa
      • Supra Mark IV
      • Tacoma
      • Tundra
      • Volkswagen
      • MKIV Jetta TDI
      • MKVI Golf TDI
      • MKVII Golf R
      • Sipster (Rabbit)
    • Other Projects
      • Powersports
      • Aprilia RS50
      • Aprilia SR50
      • Doodlebug
      • Ducati 998
      • Ducati Hypermotard
      • Honda Ruckus
      • Husqvarna TE610
      • Go Karts
      • Other
      • Sim Racer
      • Aurora Cobra
      • Garage
      • NP01 Prototype
  • Features
    • Features
      • Feature Cars
      • Drag Race Cars
      • Drift Cars
      • Land Speed Cars
      • Open-Wheel Cars
      • Rally Cars
      • Road Race Cars
      • Street Cars
      • Time Attack Cars
      • Drag Racing
    • Features
      • Events
      • Drifting
      • Land Speed Racing
      • Open-Wheel Racing
      • Time Attack Racing
      • Rally Racing
      • Road Racing
      • Car Shows
      • Columns
      • SlipAngle Podcast
  • Video
  • Shop *NEW*
  • MotoIQ Garage Services
  • About
  • Shop *NEW*
  • MotoIQ Garage Services
  • About
MotoIQ
MotoIQ
  • Tech
    • Tech Category
      • Engine
      • Bottom End
      • Rods and Pistons
      • Head and Headwork
      • Cams and Valvetrain
      • Cooling and Heat Management
      • Intake
      • Headers and Exhaust
      • Rotary
      • Engine Management and Tuning
      • Drivetrain
      • Transmission
      • Clutch and Flywheel
      • Differential and Final Drive
      • Driveshaft and Axle
      • Axles
    • Tech Category
      • Suspension
      • Shocks and Coilovers
      • Springs
      • Swaybars
      • Arms and Links
      • Bushings
      • Steering
      • Geometry Correction
      • Suspension Setup and Tuning
      • Brakes
      • Wheels and Tires
      • Fueling
      • Forced Induction and NOS
      • Aerodynamics
    • Tech Cat
      • Electrical
      • Battery and Power Distribution
      • Electronics
      • Wiring
      • Electrical System Education and Troubleshooting
      • Lubrication
      • Interior and Controls
      • Exterior
      • Paint and Bodywork
      • Wraps and Film Protection
      • Exterior Care and Maintenance
      • Data Acquisition and Tuning
      • Fabrication and Safety
      • Tips and How-To
  • Projects
    • Make A-D
      • Acura
      • Integra (DC2)
      • NSX
      • CSF RSX (DC5)
      • BMW
      • E30 (SR20 Powered)
      • E36 323is
      • E36 M3 (Black)
      • E36 M3 (Silver)
      • E39 M5
      • E46 M3
      • E90 M3
      • E46 Racecar
      • Yost Auto E92 M3
      • Yost Auto F82 M4
      • Chevrolet
      • Camaro Gen5
      • Corvette Stingray (C7 Z51)
      • Corvette Stingray (C8 Z51)
      • GMC Canyon
      • Dodge
      • Viper GTS
    • Make E-I
      • Ford
      • E350 Tow Rig
      • F150 EcoBoost
      • Fiesta ST
      • Focus ST
      • Mustang 5.0 (Grey)
      • Mustang 5.0 (White)
      • Mustang S197 (Budget Track Car)
      • Mustang S550 GT
      • Honda
      • Civic EF Racecar
      • Civic Si (Coupe)
      • Civic Si (EP3)
      • Civic Si (Saloon)
      • EJ Civic
      • Polystrand CRX
      • S2000 (AP1)
      • S2000 (AP2)
      • Infiniti
      • G20 Racecar
      • G20 (P10 AWD Turbo)
      • G35
      • G37S
    • Make J-M
      • Isuzu
      • Vehicross
      • Lexus
      • ISF
      • SC300
      • Mazda
      • V8 RX7 (3rd Gen)
      • RX-7 (3rd Gen)
      • RX-7 Restomod (3rd Gen)
      • Skyactiv 3
      • Frankenmiata
      • Miatabusa
      • My Girlfriend’s Miata
      • Mitsubishi
      • EVO VIII
      • EVO IX
      • EVO X
      • CSF EVO X Racecar
      • Professional Awesome EVO VIII
    • Make N-P
      • Nissan
      • 200SX
      • 200SX SE-R
      • 240SX Land Speed Racer
      • 300ZXTT
      • 350Z
      • 350Z Drift Car
      • 370Z
      • GT-R (R33)
      • GT-R (R35)
      • GT-R (Team America BNR32)
      • LS S13
      • NX GTi-R
      • Pathfinder
      • S13 Drift/Grip Do-it-All Mega 240
      • Sentra SE-R
      • Sentra Spec V
      • Silvia
      • STurdteen Drift Car
      • Porsche
      • 991 GT3RS
      • Cayman (987)
      • Cayman T
      • Cayman GTS 4.0
    • Make S-Z
      • Scion
      • FR-S
      • Scion Tuner Challenge FR-S
      • TC
      • Subaru
      • Autocross BRZ
      • Legacy GT
      • STI (gen 2)
      • STI (gen 3)
      • WRX (GD)
      • WRX (VA)
      • Toyota
      • 4Runner
      • AE86 Corolla
      • GR Corolla
      • Starletabusa
      • Supra Mark IV
      • Tacoma
      • Tundra
      • Volkswagen
      • MKIV Jetta TDI
      • MKVI Golf TDI
      • MKVII Golf R
      • Sipster (Rabbit)
    • Other Projects
      • Powersports
      • Aprilia RS50
      • Aprilia SR50
      • Doodlebug
      • Ducati 998
      • Ducati Hypermotard
      • Honda Ruckus
      • Husqvarna TE610
      • Go Karts
      • Other
      • Sim Racer
      • Aurora Cobra
      • Garage
      • NP01 Prototype
  • Features
    • Features
      • Feature Cars
      • Drag Race Cars
      • Drift Cars
      • Land Speed Cars
      • Open-Wheel Cars
      • Rally Cars
      • Road Race Cars
      • Street Cars
      • Time Attack Cars
      • Drag Racing
    • Features
      • Events
      • Drifting
      • Land Speed Racing
      • Open-Wheel Racing
      • Time Attack Racing
      • Rally Racing
      • Road Racing
      • Car Shows
      • Columns
      • SlipAngle Podcast
  • Video
  • Tech

Mystery or Magic? The Science Behind Porpoising In F1 Today

  • Andrew Brilliant

In recent weeks much attention has been given to the phenomenon causing F1 cars to bounce down the straights, known colloquially as ‘porpoising’. Behind the scenes, teams of experienced aerodynamicists are working quickly to find solutions.  Many have asked: how did they miss this one?

With the growing accessibility of basic CFD testing, more people are trying their hand at vehicle aerodynamic development;  accordingly, this is an opportunity to discuss some of the critical points in aerodynamic design.  The concepts involved are important both in and outside of Formula One. I hope this article will be of interest to those of you who are enjoying aero as a hobby and serve as an interesting read for those who follow it as a curiosity.

To introduce myself, I’m the director of AMB Aero , an aerodynamics consulting firm based in Sapporo, Japan.  We utilize both in-house 40 DP-TFLOP super-compute CFD and physical wind tunnel test facilities.  My mentor and partner Yoshi Suzuka was a major contributor to the modern understanding of underbody tunnels.  His work shaped them from the early F1 style ‘underbody wings’ to what would later become known as the modern ‘venturi’ style during the development of Nissan GTP cars.  At AMB Aero, we have been fortunate enough to develop all sorts of cars – especially many race cars – all over the world.  Thanks to classes like IndyCar, LMP, or even Hill Climb and Time Attack that never fell victim to the ‘flat floor dark ages’.  We have completed more than ten thousand CFD and wind tunnel tests for tunnel cars alone.  By way of relevant contrast, we also have completed work more recently in modern F1, which gives an interesting perspective from which to observe current F1 performance trends.  This said I would encourage anyone to view our perspective objectively, and sincerely welcome and enjoy hearing comments, questions, or even enlightening fresh ideas in the comments below from anyone (whether inside or outside F1).

‘Ground effect’ was discovered by accident.

In the late 1970s Lotus first discovered this phenomenon when their wind tunnel model was not sufficiently rigid resulting in the side pods sagging closer to the ground.  As they did, downforce increased sharply. Lotus engineers then sought to understand this phenomenon and in doing so determined to close the sides of the floor, leading to the now-famous ‘sliding skirts’ (that were subsequently banned).

So powerful was this ride height effect that after banning skirts, a car was run with completely solid suspension.  In this infamous test, the driver commented that the car was quicker set low and solid, but he struggled with vision and vibration.  The driver asked for a padded seat and was jokingly suggested to sit on his wallet.  Fast forward many years later and even without tunnels, Formula One and many other disciplines have far exceeded the total downforce of F1 in those days.  The concept of designing-in ride height sensitivity became deeply rooted in modern racecar aerodynamics.  Cars are generally run close to the ground to maximize underbody downforce (among other reasons), and accordingly – much as Lotus found in the 70’s – it is incumbent on designers to manage this phenomenon towards a net performance advantage.

Lotus’s early “ground effect tunnels” a simple side pod wing shape.   ref: Giorgia Piola via motorsport.com

The oldest known (to me) concept of an under-wing, dated 1928!

“Ground effect” is a dated term.

In the early days, it was believed that the effect acted similarly to the known behavior of airplane wings wherein lift increases with proximity to the ground.  You may have even felt this during a landing as if the plane is somewhat ‘cushioned’ in late descent with the pilot adjusting controls until touchdown. It was thought that we were experiencing the same phenomenon with downforce-generating (inverse) wings with downforce increasing with ground proximity.   [https://en.wikipedia.org/wiki/Ground_effect_(aerodynamics)]

Many years later we would come to understand some differences with ground vehicles and that the proximity of underbody wing forms is not the major cause of extreme sensitivity to ride height. At AMB Aero we call them underbody tunnels.  In our experience, this sensitivity is primarily due to changing flow field resulting from the relative position between the tire and the sprung body of the car.  In the case of Formula cars, this can be conceptualized as the position above vs below the floor.   Or for a closed wheel car, a tire is more or less shrouded inside of a wheelhouse.

The difference in tire exposure to underbody between high and low rear ride height.  A diffuser era car compresses with speed, effectively pivoting around the forward edge of the plank ref: f1technical.net

Related

1 2 3 4 5Next page
Related Topics
  • Aerodynamics
  • Formula One
  • Formula 1
  • AMB Aero
  • F1
  • porpoising
  • porpoising F1
Previous Article
  • Industry News
  • Features

Holley Officially Releases the SkyRam Intake for LS Motors!

  • Mike Kojima
View Post
Next Article
  • FR-S
  • Scion
  • Subaru
  • Toyota

Reducing FA20 engine Vibrations and Boosting Power!

  • Mike Kojima
View Post
13 comments
  1. Hybridesque says:
    April 4, 2022 at 1:45 am

    Brilliant article and interesting insight. Thank you for writing this!

    Reply
    1. Avatar photo Mike Kojima says:
      April 4, 2022 at 12:01 pm

      His name isn’t Brilliant for nothing!

      Reply
      1. Hybridesque says:
        April 5, 2022 at 12:54 am

        Name is one thing, his deeds and expertise are quite another 🙂

        Reply
  2. Chris says:
    April 4, 2022 at 10:06 am

    The other key issue was from a regulation standpoint. This case is not something that could be tested in the wind tunnel due to a regulatory speed limit for wind tunnel measurements.
    Quote from Mattia Binotto: “Honestly, such behavior is normal with this type of car. And it cannot be simulated in the wind tunnel because it occurs at 250-270kph and the regulations limit the wind tunnel speed to 180kph.”
    This therefore leaves only the CFD simulation and physical track testing paths for determining whether this issue exists, and gathering the data necessary to understand it.

    Reply
    1. Andrew Brilliant says:
      April 4, 2022 at 8:05 pm

      The article touched on the regulation of wind tunnel speed and scale though maybe did not explain what was to do with the regulations.

      Reply
  3. KE says:
    April 4, 2022 at 10:46 am

    Great article. Thank you for taking the time to write it for us.

    Reply
  4. Joe says:
    April 11, 2022 at 9:35 am

    Pretty certain that the current problems with porpoising has more to do with the ban on inerters for 2022. That coupled with the switch to 18” wheels (stiffer sidewalls increasing suspension frequency) probably has had an extra hand in exacerbating the issue.

    “Unofficial proposals were flying around the paddock at Barcelona testing about introducing active suspension and the return of hydraulicly managed suspension and inerters, which dampen out certain frequency moments in suspension to fix porpoising. Formula 1 banned hydraulicly managed suspension and inerters in favour of traditional springs and dampers for 2022. These were highlighted as easy fixes to solve the porpoising issues if the FIA would allow this technology to return to the cars.”

    https://www.racecar-engineering.com/articles/formula-1s-porpoising-problem/

    Reply
    1. Avatar photo Mike Kojima says:
      April 12, 2022 at 1:55 pm

      That’s more like a cure for the problem, the cause of the problem is covered by Andrew here.

      Reply
      1. Joe says:
        April 16, 2022 at 9:47 pm

        I guess that you didn’t read the linked article. I don’t believe that Andrew actually understands why this issue suddenly became a problem across all cars in 2022. Therefore, Andrew is talking about an aero solution to a mechanical problem, which *might* be possible, but is not a good method of problem solving.

        “Porpoising is an issue on most 2022 #F1 cars.
        Red Bull have found their solution in a very clever & legal suspension innovation. So they can now run super close to the track. With gas springs and inerters banned, they’ve exploited a non-newtonian fluid filled damper.”

        https://mobile.twitter.com/ScarbsTech/status/1509809156521443341

        Reply
        1. Avatar photo Mike Kojima says:
          April 17, 2022 at 9:54 pm

          He is talking about an aero problem and to me it’s pretty obvious that it is. I sort of think that careful tuning of the damper’s high-speed circuits would probably work better than non-Newtonian fluid which would work only in a narrow range.

          Reply
        2. Chris says:
          May 10, 2022 at 12:21 pm

          Joe, you should note that at the end of Scarbs’ Twitter thread, he used #April1, and also he’s quoted the suspension engineer as calling the technology something that would shorten to an acronym of PIE, while making repeated references to custard.

          I think you’ve missed the joke there…

          Reply
          1. Avatar photo Mike Kojima says:
            May 10, 2022 at 4:40 pm

            Hahaha, the joke is way at the bottom of the thread!

  5. John M Jones says:
    May 3, 2022 at 5:24 am

    Ground effect wasn’t discovered by accident, Peter Wright had been working on airfoil shaped side pods since the late 1960’s and designed a car for March with wing shaped side fuel tanks a few years later before joining Lotus.

    Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Input your search keywords and press Enter.