Racing Car Technology Racing, Road Performance, Classic and Sports Cars |
ABN Number 42 911 718 836
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Subscribers, please click
on the "Technical Pages" link to Log In. Thereafter you can move
around the site without interruption. This site is written by Dale Thompson B Sc(Eng) MSAE-A, Racing Car Technology, Batemans Bay NSW Australia. Dale Thompson and Neville Smith also operate a road car suspension workshop, Pedders Suspension, Batemans Bay.
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"Cornering speed is the key to
everything. If you corner that much faster, you
carry that speed all around the race track." Jim Hall, Chaparral
Cars. |
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What is the Key to Understanding Suspension Set Up? We use our Weight Transfer Worksheet to determine a balanced set up, and then find a direction for set up changes to try in testing. It is a very much a practical exercise - do the baseline set up in the workshop, then test. We get good results with this process. But there were gaps in our knowledge. We needed principles explaining how car handling works, that will help us understand more about what we are doing, leading to better ideas on how to change the set up (see Claude Rouelle quote above). In most text books on handling , there are few basic principles offered. The authors don't have adequate explanations. However, in undergraduate vehicle dynamics courses around the world, engineers are taught how the car works, by analyzing a model known as the "bicycle" or "single track" model. Motor manufacturers have taken this on board, leading to more complex software applications that engineers use, such as the MCAdams model. The bible of race car handling, Racing Car Vehicle Dynamics, by Bill Milliken fully explains the bicycle model. In fact, he instigated the development of the model in the 1950's. But it seems that readers pass over the mathematical concepts, seeking to get into the "how to" sections of the book. So it is that the bicycle model is not recognized as useful by the racing and performance aftermarket. Explaining Handling and How the Tyres Work We have developed explanations, based on the bicycle model, that are useful to a broad spectrum of people in racing and the automotive aftermarket - race drivers, race engineers and technicians, performance driving schools, automotive product development and marketing, and training for technicians in the performance aftermarket. "How Does the Driver Control the Car?" This important new presentation in the Technical Pages explains what is happening at the tyres, how the car corners and how the driver gets feedback from the car. Following that is another article with more specifics on tyres, the most important component of the race car. A new perspective on car handling. The core idea is a new graphical representation of oversteer and understeer, that you can see in the intro below. It could change the way you think about car handling. It is a practical model anyone can use - whether your interest is in race driving, or, the engineering side of suspension set up. You might appreciate from the videos and the intro below, that you will not see material like this anywhere else. Intro to "How Does the Driver Control the Car?" (The link will open in Microsoft Power Point.) Check out what's ahead in the Technical Pages here.
Racing By Numbers....... What's Your Category? Circuit Racing/Tarmac Rally/Hill Climb/Historic/Drift/Club Car- Supersprint, Regularity, Track Day etc Are You Building a Special, Show Car or High Performance Road Car?
Whatever you race,
whatever performance car you build.... Every racing car has a magic number. In fact, everything on four wheels has a magic number. The magic number represents the set up where the car is balanced mid corner - where the driver reports the handling is to his liking - no excess of oversteer or understeer.
The WTW represents the simple roll stiffness model of weight transfer, as explained in our presentation "How Does the Driver Control the Car?" It recognizes the major tuning adjustments we use in suspension set up, eg roll centre height, spring stiffness and anti-roll bar stiffness. We have concentrated on ease of use and practicality. Anybody can use it. Racing and road performance car workshops, or owner/driver preparing your own car, all will find it useful. As an example of the way the magic number works, say you have a rear wheel drive sedan with 55% static front weight, such as our Holden Monaro example. This might infer a magic number of 60. So we adjust the various inputs in the WTW to reflect this magic number, and change the set up on the car accordingly. This is your baseline set up. If it's a road car, you'll find it handles nicely on the road. For race cars, each time you go racing or testing, when you make changes to the set up, you re-calculate the magic number. It gives you a direction with your set ups - a higher number is more understeer than the baseline set up, a lower number is less understeer. You can spec the set up of your car by subscribing to the Technical Pages on this web site. Decide never again to fit unknown spring stiffness, anti-roll bar or shock stiffness to your car. You can be in control. We provide email support for subscribers. Cost $99-00. Subscribe now. We offer set up assistance via email with our "Weight Transfer Worksheet" (WTW), now validated for all types of racing cars - sports racing and open wheeler cars and particularly production based cars. To tune the suspension set up on your car, the weight transfer calculations are an essential first step....more Let us do the suspension set up on your car at our Batemans Bay workshop. This program is the key to developing your race car, special, project, or show car. We'll do a workshop set up, and then track test with you. With our procedures, all customers have improved better than 1/2 second to in excess of 2 seconds per laps. Some have won races for the first time.
Origins of the
Weight Transfer Worksheet. Why would you want to do any
calculations? Why aren't these calculations in more common usage? What You Will Know (about the car) if You Do a Weight Transfer Worksheet. Ten Biggest Set Up Mistakes Thought starters about set up issues.
Racing Developments in Suspension Set Up .....lead directly to new suspension set ups for sporting and performance road cars To do a set up for a racing car, we analyze how we see the car working, design and make/buy componentry, do the workshop set up, and then go testing. Similar for tarmac rally. What we bring to the table is experience over a range of cars and classes of racing, in-house shock absorber development, and some ideas and procedures born of necessity - must be low cost, no big team budget in amateur racing..... more Working with production sports and classic cars, we concluded the weight transfer theory we use for racing, can apply equally to road cars. We could work out the "magic" number" (a term coined by Claude Rouelle) for road car versions and design balanced suspension set ups. We could do this for any car. eg classic production sports cars such as MGB, MG Midget, Sprite, A-Healey, Jensen, Triumph TR2 to TR6, TR7, Sunbeam Alpine, Morgan Plus4 and Plus8, Alfa Romeo 105 series, Alfa Romeo GTV, the American and Australian muscle cars such as Holden Monaro and Torana, and Ford Esort. Cortina, Mustang, Falcon XW-XY GT, XB,XC etc , and now the modern performance classics from Holden, Ford, Nissan and Toyota.
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What's New? |
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We now offer our set up service on the
internet. The Technical Pages of this web site take you step by
step through the process of completing a Weight Transfer Worksheet - and
calculating your "Magic Number".
Subscribe
Now . Ackerman? Or Anti-Ackerman?
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Track Test With Us |
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testing of racing cars has been the key to our R&D success.
To find out about a racing car test day, click here
Now, with "Speed off the Streets" days at Wakefield Park race circuit, we can test with you driving your road car. We use a data logger (the DL1 from Race Technology, UK) to record a very accurate speed trace and track map. We get detailed analysis of car and driver performance from split times generated, and by overlaying the speed traces. You get the logger files so you can do some analysis yourself....mor |
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Road Car Performance |
When we do a performance road car set up, we try to take the driving experience to a new level. For instance, the popular classic sports and performance cars are still around because people enjoy driving them. We want to make it a sensational drive. Dan Knott, Director of SRT, the
Chrysler Corp. Performance Group put it well. "(total
integration of performance dynamics) is much more than 0-60mph times.
Synthesizing components and systems whose overall performance is greater
than the sum of it's parts - the last 2% - is truly an art. The
brakes, steering, suspension, ride, handling, sounds, touches etc., all
feel just right. This is automotive engineering and total vehicle
performance at the highest level of excellence. |