Don't let the late-model GTO...
Don't let the late-model GTO scare you away. This article applies to all Pontiacs looking for more grip on the street and the track.
As the sun crested the treeline and began to burn off the morning dew at Gainesville Raceway, I lowered the shield on my helmet and strapped in with my G-Lock. I, along with other staff members, was there to test two opposing ideologies regarding tire technology that have been hotly debated in classic and late-model online forums.
One side states that new developments in tread and tire compound technologies have allowed street tires to nearly match race tires in performance, while delivering stellar road manners on a daily driver. The other side concedes that this is true to some extent, but there is a place for a full-on race tire for a street car, and there are many benefits over the street tire. We setout to see what could be proven through real world testing.
One thing we learned through our years of racing was that race tires are soft, expensive, and wear quickly. Using them on the street is hardly a good idea, especially in Florida, a state known for its flash floods and incessant thunderstorms. Therefore, it's common practice for most racers to own two sets of wheels and two sets of tires, one for the street, the other for the track only. So we immediately realized our first mark against the race tires-practicality. Let's hope their performance justifies this sacrifice.
Wheels And Tires
Nitto provided us with its 245/40-18 NT01 and NT05 tires. The NT01 is a pure-bred race tire with a 100 treadwear rating and the ability to be shaved for competitive purposes. The NT05 is an Ultra High-Performance 200 tread wear summer tire Nitto claims out grips its highly successful NT555. It didn't take long for the NT05 to gain a cult following on the internet and out at the track. So let's find out if these street tires are worth all the fuss, and if the race tires can keep their edge.
First, we had to find another set of wheels on which to mount our NT01s. We're pretty happy with the stock 18s, but we couldn't find an affordable set. After doing some research, we contacted WheelMax.com, an online powerhouse that sells well-built affordable wheels in a variety of styles for late-model Pontiacs. We ordered a set of AZA Z-10 wheels measuring 18x8.5 to mount our Nitto NT01 tires on. They were pretty racy looking and allowed us to complete comprehensive testing.
Here is a side-by-side comparison...
Here is a side-by-side comparison of the 245/40ZR18 NT05 (left) and NT01. Note the differences in tread pattern. There's also a difference in the tread compound, which results in a stickier NT01 race tire with a low 100 tread-wear rating, and a less sticky NT05 but more durable street tire with a 200 tread-wear rating.
One of the first things you'll...
One of the first things you'll notice about the NT05 is that it has very large continuous center rib. Nitto claims this allows the tire to have more contact with the road and increases dry traction. The reinforced shoulder blocks help with stability.
The NT01 is a totally different...
The NT01 is a totally different animal. These provide maximum dry traction and aren't recommended for use in rain. They can be shaved to 3/32-inch for ultimate dry traction (ours weren't), and the large shoulder blocks increase traction during braking and cornering.
On The Road Course
One of this author's favorite features of Gainesville Raceway's layout is its road course. Secluded in the back, this drivers testing facility is HPP's testing home, and boy is it fun! The track holds test and tunes for the road course about once a month, and you should try and make it out in your Pontiac or check the schedule for your local track for a similar event. You can learn a lot about control when you take your Poncho around the course and identify the strengths and weaknesses of your car. It's the perfect facility to test our NT05 and NT01 tires back-to-back.
Since the NT05 is a street tire, the set was already mounted on our GTO. There was no fuss of having to jack the car up and swap out wheels. All we had to do was monitor tire pressure. At 35 psi cold all around, we waited to make a lap before we checked the pressure again. The heat allowed it to rise up to around 39-41 psi. We leveled them all at 35psi for consistency. (NOTE: Variable tire pressures can benefit certain tracks and applications, but we kept all four at the same pressure for the sake of our testing.)
After a single lap with the NT05s it was clear that this tire was all business. Turn-in was crisp, as was steering response, and understeer was held off until higher speeds. This told us that there was a noticeable difference between our previous High Performance tire and the latest in Ultra High Performance summer tire technology.