Streets Of Willow Toyo Proxes R888 Tire Test

R888_edited-1Finding a general-purpose DOT track tire that can do it all is a struggle. Inevitably compromises have to be made to accommodate the needs of a vehicle — either wear rates on the morning commute, traction in the dry, or traction in the wet. What if we told you a happy medium does exist and has been thoroughly vetted by pros and Joes alike.

Enter The Toyo Proxes R888

The tire to fit the bill on this occasion is the Toyo R888, a DOT-legal semi slick tire that bridges the chasm between full-race slicks, and wet-weather or traditionally grooved street tires. Originally introduced to improve upon the venerable old RA1, the R888 features design and construction to echo the success of this favored tire, while offering different features.

“We built this next-generation DOT competition tire for drivers who know what it means to really push a car.” according to Toyo’s website. The revolutionary design of the R888 is unlike the previous incarnations of wet and dry weather track tires but features identifiable technology and influences.IMG_2885

According to Drew Dayton of Toyo, “We developed the Proxes R888 100-treadwear DOT competition tire to have an optimized casing and tread design to maximize dry performance without losing wet traction. It has been designed for use in road racing, track-days and high performance driving schools.” The R888 is clearly billed to be a sticky tire with an advertised 100-treadwear rating but retains the safety and security needed to pass stringent DOT regulations.

Construction

2015-09-25_23-18-51The cross-section of a tire is a far more advanced composite of rubbers, belts, cord and other structural members than many people realize. Tires are not simply poured into a mold and ejected. The engineering involved with creating a lasting and successful design delves into materials science — of course, but also fluid dynamics and physics as road surfaces influence the response of the tire, and fluids are evacuated under the contact patch through strategic grooves.

  • Continuing his explanation of the R888, Dayton detailed, “The key features of its design include:”
  • V-shaped tread pattern to shed water and enhance wet traction control
  • A stiffer bead construction and wider tread width, which enables the Proxes R888 to generate more corning force with less heat degredation
  • It has a spiral-wound cap ply in order to maintain uniformity at varying speeds and conditions
  • A semi-slick shoulder area helps improve steering response
  • Steel wire reinforced sidewalls

Comparing To The Past 

IMG_2884The old version of the RA1 was a much loved option for racers, when Toyo opted to reprioritze the design so became the R888. Not without reason — the Proxes R888 features beneficial features to eclipse the feeling of loss many racers experience longing for their old shoes. According to Dayton, “It has a continuous center contact area which increases its braking performance and feel compared to the Proxes RA1.”

By locating the V-shaped tread at staggered intervals and eliminating any tread-lug design there is always a slick strip of rubber making contact down the longitudinal centerline of the tire. This uninterrupted patch lends itself to the aforementioned braking performance. Additionally, racers wishing to control the tread depth and weight of the R888 have the option of shaving the cap to maximize dry-weather performance.

Optimal Conditions

Like any performance tire the Toyo Proxes R888 has a prescribed ideal operating range in terms of temperatures and pressures. Unlike the typical street tire that does not improve in performance has friction-generated heat builds in the tire track tires require a little coaxing to warm up and attain their optimal traction.

IMG_2976The R888 works best in the 160 degree F to 220 degree F temperature range — either side of which it may be a little less tacky, or too gummy. Pressure for the inflation of the R888 is on the high side compared to most track tires. At 32-38 psi warm the R888 will provide the best grip and compliment steering response, and prevent the fuel economy loss generally observed with a lower tire pressure. We started with a cold tire pressure of 25 psi, which when warm netted 32 psi.

Many track-optimized cars build in suspension geometry to perform at demanding levels. One common result of this is the addition of negative camber, this squat aides in high lateral-G maneuvers but can have detrimental effects on tire wear and contact-patch area.

Taking this tendency into consideration for their target market — Toyo has designed the R888 to be best planted in a negative 1-3 degree camber situation, which is more forgiving than the increased demands of the old RA1. This design makes us aware that this tire was specifically made for the track day car or limited race car.

Testing

MG5_6063We elected to run the R888 on a typical mix of track to best see how it behaved. The track in question was one of our favorite benchmarks — Streets of Willow (clockwise). This technical and demanding track helped us put the tire through its paces under a typical track day setting.

For more consistency in our review process we opted to employ our test mule datum — Project M-Track3r. Our Supercharged E46 M3 features 402 horsepower to the rear wheels and 285 lb-ft of torque, plus plenty of aero to help push things into the ground. A good, typical all-arounder — both daily driven and tracked mercilessly.

IMG_2973With our R888s mounted on a set of Forgeline Wheels, we set to controlling pressures. Behind the wheel of the BMW would be hired-gun driver Conrad Grunewald. In order to have some proven driver consistency we put Conrad in the drivers seat and set him out to melt some rubber.

As the last tire of the day for Conrad to test, he had a fresh memory of the previous meats’ driving characteristics when taking to the streets on the R888s. “The last tires I just went out on were the Toyo R888s, it’s a really amazing tire as expected as I’ve been on them before. The one thing I can gripe about is the sidewall of the tire seems very very stiff but it makes an amazing amount of grip.” relayed Grunewald.

A stiff sidewall contributes to increased tire bead roll control, and ultimately favorable handling characteristics however some of the forgiving compliancy under normal driving conditions or rough surfaces may be lost. Given that the R888 is a DOT track tire some concessions will have to be made.

“It’s an easy tire to drive on, very compliant as they get hot they are glued to the road. the balance of the car was probably best on the R888s over any of the other tires that I tested. What I mean by that is the grip front and rear was very equal — providing a very neutral balance. I didn’t have to fight and understeer or oversteer, that was probably the biggest plus for the R888s,” concluded Grunewald.

BMW Toyo R888

Conclusion

After a full day of pounding the pavement with an assortment of tires and vehicles we established that the DOT Toyo track tires merit a favorable mention. Few option exist in the market for tires that offer both the performance and versatility of the R888 so Toyo is really an innovator in filling the crossbred vehicle market. From racers to weekend autocrossers, Toyo has a tire to fit the bill.IMG_2986

Article Sources

About the author

Trevor Anderson

Trevor Anderson comes from an eclectic background of technical and creative disciplines. His first racing love can be found in the deserts of Baja California. In 2012 he won the SCORE Baja 1000 driving solo from Ensenada to La Paz in an aircooled VW. Trevor is engaged with hands-on skill sets such as fabrication and engine building, but also the theoretical discussion of design and technology. Trevor has a private pilot's license and is pursuing an MFA in fine art - specifically researching the aesthetics of machines, high performance materials and their social importance to enthusiast culture.
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