Project Budget 400WHP S197 Mustang Track Car: Part 9 – Apex Wheels and Nitto Tires

Apex conducts extensive Finite Element Analysis (FEA) to reinforce high stress areas and remove material (and weight) where additional strength was not need.  This helps them achieve an ideal balance of strength, stiffness, and weight. The end result was our 18×11 Apex EC-7 weighing in at 22.5lbs each.

While it’s easy to compare weights, that’s only one dimension of a wheel, and often not the most important, especially for people who road-race.  If you read my article on Does Wheel Stiffness Affect Performance, you know that stiffness is extremely difficult to quantify but an extremely important aspect of a wheel.  If a design is solid (like the EC-7 using one of the best fundamental geometries of an aluminum wheel) the only way to add further stiffness is to add mass; and thus, increase weight.  If you see a super lightweight wheel with a ‘fancy’ intricate spoke design, it’s likely a flimsy ‘noodle’ that flexes and loses dynamic camber in corners – hurting performance and requiring you to run more static camber.

The EC-7 has a solid design and does not throw any red flags in terms of being ‘too light’ or the lightest in class.  These are likely two fundamentally important characteristics that have given the EC-7 a proven track record of being durable and successful on track.  This combined with Apex’s impressive warranty makes the EC-7 a great choice whether you race, track your car, or looking for better wheels than stock.

The Nitto NT01 has been around a while and while it’s not the fastest tire on the market, its true strength still shines today as one of the most confidence-inspiring, durable, consistent, longest-lasting track day tires.  The NT01 maintains its performance in cold and hot weather, on heavy and light cars, from new to old, and after multiple heat cycles.  Its high modulus rayon carcass and body-ply construction and compounding make it very easy to drive and forgiving, while delivering great communication, stability, and driving characteristics on all different types of cars.

With full tread, the NT01 works well in the rain, and when the horizontal tread features wear down, the tire becomes essentially a slick with only two circumferential grooves.  When it’s worn down like a slick, steering response improves, tread squirm is reduced, and it really starts to perform like an easy to drive slick.  For most drivers, having a consistent tire is extremely important to be able to gauge the improvements in their driving, as well as to be able to tell what the car needs from a setup standpoint.

These characteristics makes the NT01 one of the best tires for the track day enthusiast where throwing new tires on each weekend does not fit in the budget.

HISTORY LESSON AND EDUCATION

Times were simpler back when the NT01 was introduced in the mid-2000’s.  There were street tires, “R-Compound” tires, and racing slicks.  Today, UTQG treadwear ratings are now an obsolete and outright pointless metric due to tire manufacturers fighting for the desirable ~200 treadwear market by creating ‘street-tires’ with sticky and aggressive racing compounds that greatly improve lap times and performance in order to generate sales and market dominance. Even though some car groups, clubs, sanctioning bodies, and race series still recognize UTQG ratings for some classes, they are no longer a reliable metric and really should not be used to determine the ‘stickyness’ or performance of a tire.

Because of this, there are many “street” rated tires that are stickier and faster than the NT01.  If you compete in these classes then you are forced to choose the best tire available at the arbitrary UTQG rating the event organizer chooses: 180, 200, 220 UTQG etc….  However, many of these ‘cheater’ street tires are so soft that they are only fast for a few laps before overheating, or don’t even work on a heavy car on a hot day before getting greasy.  For most track enthusiasts, having a consistent, long-lasting high-performing tire is more important than a slightly quicker tire that wears out quicker.

The NT01 has wear indicators around the entire tire with two different hole sizes.  The larger, outer hole signifies the tread depth of the top-half of the tire that has the horizontal features.  The tire is molded at 6.3/32nds of an inch in thickness.  Once these features wear away, the smaller inner hole indicate how much tread is left in the bottom-half of the tire before getting to the cords, which is 3/32nds of an inch.  The NT01 delivers consistent grip all the way down to the cords.

Quick Reference:

Page 1 – Intro & Palm Beach Motorsports
Page 2 – Apex EC-7 Tech
Page 3 – EC-7 Weight & Nitto NT01 Tech
Page 4 – NT01 Weight & Mounting
Page 5 – Mounted NT01 and EC-7 Weight and Comparison
Page 6 – Wheel Weight Comparison and Install
Page 7 – Wheel Spacer Tech and Clearances
Page 8 – Rear Wheel Clearance
Page 9 – Installed Pics