7 Little-Known Hacks to Race Car Handling Mastery [EBook]
Every racer knows suspension set-up is a key ingredient in making your race car faster and improving your driving performance.
But how can you learn about this stuff?
Magazine articles, "cheat sheets", and generalized advice you get on set-up from internet web sites, are particularly unhelpful. The performance aftermarket suppliers and preparation workshops are not properly equipped to give you the advice you need. (They'll give you advice from their experience, often without any real understanding of the processes.)
No wonder the general impression most racers get is:
- A true understanding of handing is too complicated for most racers. Even those that should know, the performance suspension parts suppliers, are not sufficiently interested to research suspension set-up for themselves, let alone advise their customers properly.
- You can pretty much take the piecemeal advice you get with a grain of salt.
It’s about this point that most racers give up on a serious look at set-up. You tell yourself, “I have to be satisfied with what I’ve got. I’ll just make what improvements I can as I go”. You’re chasing one “shiny object” or idea after another – whatever is the flavor of the month.
This new e-book from Racing Car Technology, “7 Little-Known Hacks to Suspension Set-Up Mastery” is different. We show you a complete overview of handling and set-up that every racer can understand.
It's also intensely hands on. We've been doing race car set-ups for nearly twenty years. We'll show you the steps to specifying a "baseline set-up" for yourself.
The "7 hacks...." are 7 little-known insights into race car handling.
Taken together, they give you a unique overview of handling that could transform your understanding of what’s required to do your own suspension set-up. (If others do the work, you can tell them what you want done.)
At the risk of sounding a bit hypey, the blueprint we show you in this ebook could be your light bulb moment in making your way forward with your racing. At least, I hope it’ll start you thinking.
Fortunately, the core theory of vehicle dynamics is not complex. We can move from the complexity of what’s happening at the tyres to staggeringly simple explanations of how driver control and response of the race car works.
Driver control and race car handling is about optimizing the behavior of the vehicle in response to the driver inputs. If we’re going to understand the physics involved, we need to consider the race car and the driver together.
So, we’re going to talk driver control and vehicle response in Hacks #1-3 before we get into set-up procedures in Hacks #5-7.
Here's the 7 Hacks in outline. Get all the details and a deeper understanding in the ebook.
Hack #1 The Racing Driver's Feel for the Car Explained
The driver's primary feel for the car is a rotation motion in the ground plane. At slow speeds on the road, there is no appreciable rotation for the driver to feel. However at racing speeds, the race car builds up a side slip attitude to the direction of travel, a rotation motion. The car adopts a nose-in attitude, as shown in the middle diagram.
This rotation motion can be discernible to the driver, as the "body slip angle", β, builds up in corner entry. If the body slip angle is building too fast, then this is instant advance warning to the driver, that the car will go into a spin unless the driver counter steers, or takes other corrective action.
The race car always rotates around the the centre of gravity, whether it is the initial sensation of the race car gripping up in the corner (the middle diagram), or whether the car goes on into a spin, as per the top diagram.
Hack #2 Driver Inputs and the Race Car Response
"Steady State" Cornering
The car in cornering is only rotating around its own axis while the driver is applying control inputs to the car in cornering – braking, turning the steering wheel, accelerating. When the car has taken a set in the corner, it is no longer rotating. The body slip angle is now a fixed angle. We say the car is in steady state cornering.
Hack #3 The "Neutral Steer Point" and the "Static Margin"
The static margin is an alternative way of looking at understeer /oversteer. The term has it's roots in aircraft engineering. The neutral steer point behind the CofG, as shown in the diagram is positive stability.
Understeer is positive static margin, positive stability. Oversteer is negative static margin, negative stability.
If the car is being driven on the limit of grip:
+ve stability (NSP behind the CofG): Apply steering input, and the car is stable - you can feel the rotation slowing down as the car takes a set.
= 0 (NSP and CofG same location): With steering input, the rotation feels like it wants to keep going. There is no appreciable damping of the rotation.
- ve stability (NSP forward of the CofG): The car is unstable. Any input causes rotation that has to be corrected.
The "Balance Trade-Off" *Key Concept*
V8 Supercars Champion, Scott McLaughlin, said after his first test in the new Mustang: “You have to have a bit more give and take; so I go ‘give me bit more turn’ but then I get loose in the rear. So, then I go ‘I’ll give you some of that turn back and you give me some of that rear back.’ So,
it’s a bit of a trade - off.” Auto Action Issue #1755
It’s clear the driver’s task in optimizing the speed and path of the vehicle comes down to this balance thing. Yes, it’s up to the driver to find the best way through the corner. But ultimately, it’s all about this finely nuanced seat of the pants feeling of the rotation that’s an integral part of the driver knowing where the limit of grip is.
Hack #4: Classical Vehicle Dynamics Was Developed by Flight Dynamics Engineers in the 1950's
A little history to put some context around the ideas of race car stability and control.
The theories of classical vehicle dynamics were first proposed by Bill Milliken and his flight research organisation, CAL in the 1950s. In 1995, he co-authored the race engineers/designers bible. "Race Car Vehicle Dynamics".
Hack #5 Roll Stiffness Distribution - the Suspension Tuner's Primary Tool for Set-Up
Roll stiffness distribution, front roll stiffness vs rear roll stiffness, determines the weight transfer distribution front vs rear, and therefore the balance of the car for understeer/oversteer.
Many racers do not fully understand this, and how crucial it is. If you want to adjust your race car for best mechanical balance, you need to know this. Period.
Hack #6 Get a Baseline Set-Up with the Racing Car Technology Weight Transfer Worksheet™
In this Hack we show you what's needed for your "baseline set-up" - the set-up you can do in the workshop, then go to the track knowing you have the car in the set-up window.
If you have a late model factory built race car, the factory will give you the spring and anti-roll bar adjustment options and the suspension geometry required for a balanced race car.
However, for one-off/low volume race cars, historic race cars and all types of production based race cars, even current race winning cars, you will find most times that the set-up can be improved by implementing a good baseline set-up. For some of our clients, we've achieved seconds improvement in lap time straight off the trailer.
Hack #7 Test at the Track to Optimize Performance
We need to test to see if the car is in the set up window, as indicated by our set-up in the Weight Transfer Worksheet™. And if not, why not.
If everything works out to plan, then the car can be final adjusted for best balance on the anti-roll bars.
Most racers don't test because they're unsure what to do. Get your head around the first 6 Hacks, and your test day will be a breeze. You can look forward to ever improving as you develop your race car.
I’m hoping to spark your curiosity. To examine and ponder further how race car response vs stability methodology could help with your driving performance and guide you with improving your race car set-up - ie look at all the possibilities that can be unlocked.
I'd love to hear what you think of the book. If you'd like to get in touch, email me, Dale Thompson on [email protected].