Project EP3 Si, Going 5 Lug with Wheels from Enkei and Nitto NT05 Tires

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The RPF1 in 17×8 is a super respectable 16.2 lbs, not as light as a high quality fully forged wheel but as light as the lightest cast wheels while being much stronger.  Even with its light weight, the RPF1 is very strong and can take the heat of competition as we know of many pro teams using it in a variety of motorsports ranging from Formula Drift to Rallycross.

The NT05 has a carcass designed for ultra high performance.  The tire’s casing is made of two plies of polyester with a  high-end turn-up.  The turn up refers to the turn of the plies as they go around the bead of the tire and back up the sidewall.  High turn up means that the termination of the plies is higher on the sidewall than normal giving the sidewall 3-4 plies of stiffness from the bead to the tread from a  two-ply casing.

This stiffens the sidewall in the bead area, improving handling by quickening response to steering input while still allowing the sidewall to flex a little in the tread area for smoother ride and layout of the tread to the ground plane for better grip by reducing sensitivity to tire shock.

The NT05 has two steel belts that increase puncture resistance and reduce tread squirm, helping keep the tread flat on the ground without lifting under side load when the sidewalls distort.

A spiral wound aramid (aramids are super strong synthetic fibers like kevlar) cap ply prevents tire growth and keeps the tread center from bulging at high speeds, reducing heat build up and improving the tire’s speed rating.  The spiral winding eliminates the need for the typical way of joining the cap ply, a lap seam which is a weak spot under load and an area of differing stiffness that can cause problems at high speeds due to centrifugal force.

The tread compound also works exceptionally well in both wet and dry conditions and is a big step up in grip capability when compared to the long wear biased compounds used in other Nitto tires designed more for long life. The NT05 has two large circumferential grooves to resist hydroplaning while the large tread blocks with narrow grooves on the sides of the tires give good lateral grip.

Isaac used to be a professional fender roller in his previous life and had a thriving business rolling fenders on hundreds of different cars before he became an engineer.  Isaac set off to work getting us more fender clearance.

One thing Isaac stressed is to use the proper tools and techniques. Going at it with a baseball bat or getting too aggressive with a proper fender rolling tool can result in rippled quarter panels, cracked paint and damage to the quarter panel which can lead to premature rusting.