Ask Ross

Q&A with Ross Bentley


Q: How do I find the ideal pressures for my tires for driving on track?

Q: “I’m looking for the formula to adjust my cold tire pressure based on the ambient air temp. I had heard someone at the track mentioning this but missed getting the formula. I have used the pyrometer to ensure I have a tire pressure that gives a very even temp across the tire, let the tire cool overnight and took the tire pressure as my future starting cold tire pressure. At the same time, I recorded the ambient air temp to have record of both. My question is, if on the next time to that track, the ambient air temp is higher or lower than the day I recorded my previous tire pressure, how much do I adjust my cold starting pressure? Of course, I have done all of the above for each tire, arriving at four different starting cold pressures. Is there a formula that will give me the adjustment?”

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Q: How can I adapt to driving different tracks, and having different instructors?

Q: “I’m new to HPDE and have done 2 events so far. I live in Colorado and my first HPDE event was at Pueblo Motorsports Park. I drive a modified Miata and my instructor at the time thought I did amazing and that I took all the right lines and everything on the track. I was “in the groove” so to speak. My instructor thought I was good enough to advance to HPDE 2 and I told him I wanted to stay at 1 to be safe because this is only my first track. I then went to my second event at High Plains Raceway and had a completely different instructor. At that track I could not “get into the groove” and went completely off track at turn 10 twice. I kept pushing myself even after because I knew I could do better, but I felt I was not getting any better. What I’m saying is I was extremely comfortable racing at Pueblo and thrown off by High Plains, due to either the elevation changes on the corners or the track having, in my opinion, odd lines. My instructor had taken me in his car around High Plains to show me the lines I should ideally be taking, and I noticed he wasn’t using the entire track width. But the next time I went out I mimicked the exact lines he was using and he said I wasn’t using the proper lines, and it dropped my motivation a little bit. What I would like to ask is how I can adapt myself to become comfortable to different instructors and different tracks?”

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Q: Does turning the steering wheel more in the middle of a corner make me faster?

Q: “I notice that many of the top drivers turn the steering wheel more right in the middle of the corner, just about the apex. But I never see anyone teach it. Example: Lewis Hamilton’s record lap at COTA on YouTube. I have found myself doing this on the sim and some in my car in real life. In the slow speed turns on entry, they add X amount of steering input, then as they approach the apex and are scrubbing speed, they add more input. This makes sense because as you slow, the tires will take more input. Comments? Good? Bad? Too complicated for amateurs? It seems pretty natural to me on the sim? I presume if it is used during a record lap, it must be faster?”

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Q: What is “fishtailing” & how do I control it?

Q: “What causes the phenomenon known as “Fishtailing” and how do you stop it? I was at a HPDE event at Road America many years ago and the instructor said a quick stab of the brakes would stop it. I’ve have only gotten to use it when towing an unstable race car trailer, and it did work on that. Should that work in a race car or on the highway?”

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Q: Any comments on the similarities between skiing and driving?

Q: “I’ve been an avid reader of your content since about 2002, and I find that you always have some new angle of providing new knowledge to us drivers. I have a question that’s a bit borderline off-topic. I don’t remember whether you’ve mentioned alpine skiing anywhere, but even as an inexperienced skier I find there are some similarities which could actually help my driving. For example, the use of vision, the importance and use of balance, and of course, the way of finding “the line.” I know that you often look into other sports to find ideas for use in car racing, and therefore I want to ask you if you know of any good alpine skiing “speed secrets” books to explore?”

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Q: Do I need to learn how to double clutch downshift?

Q: “I’m currently reading Skip Barber racing school’s book “Going Faster” and came to the chapter about shifting. The author wrote that race cars usually don’t have synchros, and thus require double-clutch for downshifting. Since the book was written in the ‘90s, I’m wondering if it’s still true for race cars nowadays? Is it a required technique if I plan to develop my racing career in the future?”

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