December 21, 2023

Shaine Collins Killin It!

Spec Tires

This is a topic that comes up every so often and without understanding that happens behind the scenes, it can be difficult to see the importance of spec tire choice. It’s not as simple as it may appear.

We hear it all the time, I tuned my chassis for such and such tire, so I want to run them here. Why can’t I? Your spec tire is too slippery and my car is slow here. I can’t even keep up. Hm.

Tire choice for every track is important. One of the most important decisions in my opinion. Ever since we had a track, one of the biggest decisions was which tire will be our spec. This decision will affect the speed range of the cars, and ultimately the flow of the track. In addition, it will affect how everyone ends up tuning at that particular track. If a tire has too much side-bite, people will tune to lessen it. If a tire has very little side-bite, people will tune to increase it. Same goes for forward-bite. Recently it seems the majority will also tune for more speed. Not my favorite thing, but recently that seems to be part of the trend.

So why doesn’t everyone just settle on one specific tire and be done with it?

I, or should I say we (all track owners) wish it were that simple. Unfortunately it’s not even close.

Track Surface Matters

One of the biggest factors in choosing a spec tire is track surface. This has the most influence on which tire should be used. There are as many different surfaces as there are tires out there. Polished concrete, raw concrete, sealed concrete, various epoxies, asphalt, P-Tile (many different brands with different compositions), porcelain tile, linoleum, carpet, the list goes on and on. Each surface has it’s own characteristics and will react differently with different tires being used. Some will be closer to each other than others.

Frustrating Lesson

In the early days, our track was Polished Concrete. There were some mainstream companies with 1 or 2 tire compound offerings and others with a greater range. Back then tire selection was easy. Pick the one closest to the speed you want, and that’s it. There were always huge compromises, but we were at the mercy of the companies making tires. It was all about tuning around those differences.

After a few years, I started talking with Wee from DS Racing and he had a lot of different compounds. I told him what I was looking for and he sent me a batch to try. He knew our surface, and sent me his slowest range of tires, rating them from slowest to fastest. I got to testing.

Confusing Results

I found that although DS Racing had tested and rated their different compounds, my results were not inline with their ratings. DS Racing sent me more tires to test, and again we found out results did not line up. We discovered that although the surfaces tested on appeared to be the same, for whatever reason the results were not the same. Maybe humidity, concrete composition, whatever it was, it was definitely not reacting the same. We discovered no matter how close the surfaces may appear, tires need to be tested to find the desired speed and characteristics. This also goes for the various P-Tiles and other surfaces. There are so many factors that come into play, temperature, humidity, dust and dirt, cleaning solutions used, cleaning frequency, etc. Even the same P-Tile in different locations can feel completely different with the same exact tire.

Tire Testing Isn’t Quick or Easy

Over the years I have tested just about every tire I can get my hands on. I have crates of test tires. I have spent countless hours and laps trying to figure out which tires to choose. So tire choice here is not taken lightly. Contrary to popular belief, the hardest tire is not always the slowest and slickest. Not only that, but there is far more to be considered than just how hard a tire is. For our latest surface, Toli P-Tile (or J-Tile as it’s being called as of recent), I tested over 20 different tires to finally settle on our spec tire. (I’m always testing different tires here) If we had a different brand of tile, there is a very good chance we would be using a different spec, or not. It really just depends.

Long Term Testing Is A Must

After finding tires that I find have the characteristics I am after, I then go into long term testing. That means I will continue to run them until they are worn well. I have found many tires to change considerably as they wear in. Some slow down and some speed up. Some go from being really slick, to super grippy. It just all depends. I have found no rhyme or reason for this. Even the tire manufacturers are not 100% on why.

What do I look for in a spec tire? A multitude of things.

Since we hold competitions here, a deal-breaker for me is if I tire starts out fast (high traction) and slows down as it wears in. This would give the people running new tires an advantage, and punishing those practicing with them. Or it would become a money game where competitors would need to buy more than 1 set to be on a level playing field.

Another deal-breaker is if the tires become too fast once worn in. After a day, you have people just racing around the track. I have found some of the harder compounds exhibit this trait. They feel great and run slow and smooth for the first 2-3 hours, (Sometimes even longer) then all of a sudden they are really fast and grippy. I can’t tell you how many tires we have found this with.

So I’m always searching for a tire with a nice balance of side-bite and forward-bite, that will start out slower than worn in, but will reach an acceptable speed within about 1 hour. (That’s about the limit I set for myself.) Then long-term they cannot become more grippy than what they are at the initial break-in. Finally, the speed needs to be correct for the track. I feel a smaller, tighter track needs a slicker tire than we’ll say a larger track with big, wide open sweepers and generally wider turns. At the end of the day, it’s really what the track owner has envisioned for their track. We are all lucky enough to have tracks opening up recently. So we should be grateful we have more places to enjoy our hobby now. It wasn’t that long ago where we were all setting up in parking lots.

In Conclusion

There is not one perfect tire to rule them all. If everyone is somewhat on the same page as far as what handling characteristics they are after on their particular surface, that is the best anyone can do. Keep in mind, they won’t be exact when compared to other locations. Then again, if it were all the same it wouldn’t be fun. Part of being a good driver / tuner is being able to adapt and tune for any condition. As long as everyone is on the same tire at the same location, it’s all about tuning, driving, and having fun. The main take-away from this, using the same tire on different surfaces does not guarantee the same handling characteristics. In fact, in most instances it will not. If you are trying to match one track to another, you need to find a tire that works with your particular surface to provide the same speed and feel. As always, this is just my opinion. These are my findings and it works for us.