Tires are a very personal preference-driven component. Everybody has a brand or model that works best for them, and they stick with it until they are knocked off the podium. For the weekend track driver, NASA, or SCCA competitor tires are a budgetary place holder. You can always plan on going through them at a regular rate. Of course, the temptation of tire selection is a double-edged sword. Do you go with a hard compound that lasts, but one that lowers your cornering speed? Or do you throw your wallet to the wind for the uncompromising grip (and accelerated wear) of sticky rubber?
Enter The Toyo RR
Toyo produces three track-dedicated DOT tires for applications ranging from all-out dry (RR), intermediate (R888), and wet weather (RA1). On a sunny, Southern California day, we decided to put the semi-slick RR to the test. The Toyo RR features a symmetrical two-groove design for longitudinal stability. Purely a dry weather tire, the RR has sighting holes for tread depth spaced such that inspection can be done at any clocking. The 4/32-inch tread depth boasts favorable wear characteristics, while retaining a rubber compound that sticks to the asphalt.
According to Drew Dayton of Toyo, “The RR features a reinforced sidewall and high-modulus bead filler to provide excellent steering response and feedback.” He continued to describe the construction of RR as containing,” an advanced, race-proven, rayon carcass offering improved handling with increased consistency and durability. Two wide steel belts and a spiral wound nylon cap ply provide consistent lap times throughout the lifetime of the tire.”
The RR performs best when up to temperature, like all track tires. With an operating temperature range of 160 degrees F to 220 degrees F, drivers are expected to put these tires to the corners with some enthusiasm. Building heat, and maintaining it is important to the traction offered by a compound like the RR.
The Test Site
We are always keeping and eye on the trends in track tires and decided a thorough test of one of the biggest names in performance DOT tires, Toyo, was in order. How should we do this, drive the back roads? Set up cones in a parking lot? Nope, we weren’t messing around, so we reserved The Streets at Willow Springs for a complete day of track testing.
While we all like to think of ourselves as Formula 1 robot-precise drivers, our fragile journalist egos are only half diluted. For an independent and consistent benchmark we employed a professional track driver, Conrad Grunewald. Grunewald is extensively qualified with a background in Formula Drift, SCCA, and international racing for Ferrari. While we would collect “butt-dyno” impressions of the tires, we left the real evaluation to the guest of honor.
Test Vehicle: Project M-TRACK3R
To test the Toyo RR we decided to utilize our most track-dedicated mule Project M-Track3R. Our BMW M3 features extensive aero, suspension, and engine work putting around 400 horsepower to the ground. A typical track day car, relatable to many enthusiasts who might opt for sticky tires over a harder compound.
Our M3 is suspended by Bilstein Clubsport coilovers, and is stopped by Brembo GT 380 mm, four-piston front calipers and slotted rear rotors. Whiteline control arms, and bushings firm up the rear end for a more race-bred suspension feel.
Holding onto the test rubber are Forgeline GA3R wheels. These forged and milled 6061-T6 aluminum race wheels are three-piece design, and feature titanium fasteners, I-beam spokes, heat-treated components, and a 2,100 pound rating.
Out on the track the car was visibly more planted from an external point of view. Grunewald was able to maintain more speed at turn-in, and hold the road at higher lateral G-loads. From a spectators perspective, the tires appeared to offer improved stability through, and beyond the apex of the corners, inspiring confidence in trackside photographers, and driver alike.
We sat down with Conrad after had run the M3 through the corners at Willow Springs; here’s what he had to say about the Toyo RR.
Grunewald: Regarding the Toyo RR, one thing that stood out isn’t necessarily that it corners that much better, or that it brakes that much better. It’s when you try to do two things with the tires that it stood out. When you’re trying to brake and turn, or accelerate and turn, that’s where the Toyos really stood out as having a lot more grip. It’s a proper slick tire. Compared to a street tire, the Toyo RRs really do a good job of combining forces on the car. Straight-line braking performance — yes is great but, it’s not amazing compared to a street tire. When you try to brake and turn it’s pretty amazing how much grip the tire actually gives you.
Turnology: Tires are not just about traction, driver feedback is an important part of knowing the limits of a car. How the tires respond to pressure, and driver inputs are just as important as their ultimate performance.
Grunewald: On the Toyo RR, the sidewall-to-tread grip felt pretty compliant. I really like the feel of it. I think we had too little tire pressure in it to begin with, we bumped it up a couple pounds and it made a huge difference. The car went about 2-tenths of a second faster when we went up on tire pressure just a couple pounds. It still had that really nice feel of sidewall movement to tread sliding. I think it’s important for the tire to communicate well with the driver, and that’s something it did really well.
The Toyo RR, while retaining a DOT approval rating, is a real race slick. These tires are uncompromising in their design and performance. When paired with a vehicle equipped to compliment their characteristics they show what a difference the right rubber can make in terms of lap times and corner speeds. Even as a spectator the perceived increase in traction is impressive. If you have a track car in need or tires or have questions about applications for the RR, contact Toyo tires.