"Find some tires that are reliable and affordable, figure out the right inflation pressures and have fun flogging your toy. And don’t let the tires freeze in winter storage!"
The Racing and High Performance Tire
by Ziva Allen
We first heard about tire guru Paul Haney when Ross Bentley introduced him to us via his Speeds Secrets Weekly. Bentley went on to conduct a four part webinar with Haney entitled Get Smart About Tires & Drive Faster. The webinar covered rubber friction, weight transfer and everything in between. If you want to learn how to go faster, you must get smart about tires first. But if you missed the webinar, check out Haney’s book, THE RACING & HIGH-PERFORMANCE TIRE: Using the Tires to Tune for Grip and Balance, which is a must read. Here is what Haney has to say about the book:
This is a 288-page, hard-bound, book that will explain the complexities of rubber and tires as well as basic vehicle dynamics. Do you know how an anti-roll bar works and why? Do you know what wedge is and does? Do you understand roll centers and how they affect weight transfer? This book will explain those important racing concepts and many others. In an interview Mario Andretti tells how he drove the development of racing slicks and stagger for Big Cars. I explain the real reason why his discovery was an accident.
We asked Haney to talk to us about his field of interest and what we can expect to learn about tires from his webinars, seminars and book.
Q: Paul, how did you first become interested in tires and their effect on car handling?
A: My first book, Inside Racing Technology, had 32 pages on shocks and shock dynos. People said I should write a shock book. Five years later I finished the tire section of the shock book and published it as The Racing & High-Performance Tire. During that time I learned that nothing happens with a car that doesn’t involve the tires. A four-wheel vehicle with tires, shocks and a human driver is an extremely complex system.
Q: In what ways have you educated yourself about tires and car handling?
A: My interest in cars started when I was about 12 years old. An article in Hot Rod magazine explained that brakes slow a car by using friction to turn the kinetic energy of the car into heat. That stimulated my curiosity. I wanted to know more about how things work so I went on to earn a BS in Mechanical Engineering. Then I worked for five years in jet engine development at an aerospace company. Then ten years at a materials company in manufacturing and product development. All that time I kept up with cars and racing. In the 1980s I wrote race reports and articles for The Wheel, the monthly San Francisco Region SCCA newspaper. I started a monthly newsletter and then wrote three books on technical motorsports topics. I spent a lot of time at race tracks talking to engineers and working on my own cars.
Q: Do you race cars or participate in high performance driving events?
A: Not any more. I drove several different cars when I worked for a racecar prep business at Sears Point and I drove my Lotus Elan in Solo 1 at Sears Point and Laguna Seca. I really enjoyed driving fast on a track but I never revealed any significant talent for driving. It didn’t help that those tracks don’t have much in the way of runoff areas and I was driving my own car on a tight budget.
Q: We understand you offer seminars to discuss the importance of tires. In a nutshell, could you tell us why you believe having an understanding of tires and their impact on car handling is so important and beneficial?
A: Attendees learn the basics of how tires work on a car including rubber friction, design variables, tire behavior, weight transfer plus real-world examples and the care and feeding of tires. In an online format attendees can ask questions at any time and, after a formal presentation we take questions for an additional 30 minutes.
Q: What general advice would you give to an HPDE participant about choosing and managing his/her dedicated track tires?
A: Find some tires that are reliable and affordable, figure out the right inflation pressures and have fun flogging your toy. And don’t let the tires freeze in winter storage!
Q: A friend of ours ordered a Porsche GT3 with spec tires for a European racing series. He underestimated their grip level and totaled the car during his first run group at Sebring in Bishop Bend. He was the chief instructor for a major club racing and HPDE organization. He retired from HPDE following this incident. Albeit with this limited information, can you explain what happened and how it could have been avoided?
A: Humans are capable of really dumb and extremely brilliant acts. A car like that demands the utmost in respect. Maybe something strange happened but, in the end, the driver is responsible for what the car does.
Q: How can an HPDE driver determine correct tire pressures?
A: That gets complicated because of the interaction between pressure and temperature. We spend some time in the webinar explaining that from several different angles. The short answer is to start with cold/hot pressures recommended by the manufacturer/track support. Diligently record pressures and ambient conditions for every track session. Take tire temperatures if you can.
Q: Can an HPDE driver benefit from taking tire temperatures? Please describe the process, assuming the individual lacks a race team.
A: Taken properly and consistently, tire temperatures can tell any driver a lot, especially when making suspension modifications and/or adjustments. But tire pressures and ambient conditions are also important. There are a lot of trade-offs and interactions. I cover this topic in my book.
Q: When I first started participating in track days and achieved solo and later instructor status, I drove on Hoosier slicks. A compound change led my track support provider to switch his customers to Michelin Pilot Sport Cups. Now we use track tires that can be driven to and from the event and we like the convenience of not having to change tires or worry about getting the track tires to the event. What is your opinion of the host of new tires that can be driven on the track and the street - the Kumho Ecsta XS or the BF Goodrich G Force Rival, for example?
A: This is an example of the performance, reliability and pace of development of the pneumatic tire. Even 20 years ago street tires would not have held up to an average track day.
Q: What tires do you currently have on your racing/track car and why?
A: I don’t have a track-day car right now. If I did, say a 10-year-old Miata or Corvette or Boxster, I’d put inexpensive radial tires on stock-width rims. I’d find a comfortable inflation pressure taking tire temps and then I wouldn’t spend a lot of time worrying about the tires, giving me more time to enjoy flogging my toy. A simple data system would show me where I could improve as could some driver coaching but I’d try to avoid competitive urges.
Q: Tell us what we can learn from reading your book.
A: People learn how tires work on a car, tire performance characteristics and some care and feeding tips. I debunk some myths and discuss some WHYs of tire performance. I explain rubber friction, car balance, the importance of inflation pressure, what the shocks are doing, anti-roll bar trade-offs and weight transfer timing.
My book, The Racing & High-Performance Tire, is the only source of this information. The book is available on my website, insideracingtechnology.com, sae.org, and amazon.com.