Spec Miata Tire Testing

Sometimes you get lucky – and this was one of those days.  I was given the opportunity to participate in a tire test.  I’ve driven tire tests before, but this was different.

This time I drove a car that was all wired up - infrared sensors (3 per tire) that recorded the temperature 10 times per second.  What would you want to know if given the opportunity?  I am still overwhelmed by the possibilities.

The only important goal for the day was to determine that the stuff worked.  Friend and teammate, Chuck Hall, had started this project with the help of Roger Caddell of Victory Lane Data (an AIM dealer and trainer).  Chuck fabricated devices that we hoped would make it possible to drive the car on a race track at race speeds and know things about Spec Miata tires that nobody would tell us.  Hopefully nobody would get hurt.

I arrived at the top secret test site (shortly after having driven through a snow storm) to find that a skid pad had been laid out and test runs in both directions already been done – the sensors all seemed to work.  I was told to get in the car and give it a whirl.  Whirl it was - ten times around the course and I was dizzy.  I tried driving 10 laps the other way to unwind – that doesn’t work.   

So, we had a problem - we didn’t have room enough for the size skid pad we wanted.  After some adjustments to the AIM data logger’s settings and correcting some crossed cables, we had confidence that everything was in order.  Team manager, Peter Lovejoy and I laid out a mini-course that would more accurately represent race conditions and keep anybody from hurling.  We sent Chuck and our friend, Hollywood Stunt Man and the guy you call if you want your very own “General Lee”, Jamie Smith out to hold the timing beacon (see photo) so we could have a familiar looking test in a format that we could more easily analyze later.

SUCCESS – this thing works!!!  We ran tests in both directions and we didn’t knock anything off of the car.  It had been decided to use different camber and tire pressure settings on either side of the car so we could gather two sets of data without having to do set-up changes in the field, in a snow storm.

As I was completing my runs, teammate Jonny Davies arrived.  Jonny has a great feel for these cars and lots of test experience.  We did a series of tire pressure adjustments and have another nice chunk of useful data from which to help design the next test. Now the real work begins.  Who’s going to figure out what all of this means?

My first instinct, which occurred early in the test, was to remove the tire pyrometer from my tool box – that space is now better used for storing condiments.  Actually, I had that instinct before, now I have some data to back it up.  The next test will include determining the relationship between pyrometer data and what is really happening to the tire.

Brian Towey