As the latest release from 5Zigen, the cast one-piece ZR+520 is designed for strength and an easy fit. After bending what we thought was a nearly indestructible Enkei, we're big fans of strength. The 18x9.5 wheel, with a plus-30mm offset, fits the Evolution platform perfectly. The front wheels clear the Brembo calipers with ease and the wheel/tire combo can even clear the stock suspension, although rolling of the rear fenders was absolutely necessary. Our late-night, last-minute request was handled by Teddy Hiraoka and the fender roller of Mavrik Motorsports.
The only real downside to the ZR+520 is weight. At 26.5 pounds each, there are many lighter options. With the 265-width R888 mounted, our race tire package weighs 4.5 pounds more per corner than our 245-width street tire package (53.5 pounds versus 49 pounds). But it's a balance, because you'd be hard pressed to find a wheel that can beat the ZR+520's ease of installation, price, size and availability.
With our rolling stock figured out, it was time to tighten up the suspension. The ST and SP classes allow the same important suspension modifications, but we'll always reference the Street Prepared section of the rulebook. According to SP rules, we could use any shock absorber (Section 15.5, C), adjustable spring perches (15.8, A), different bump stops (15.8, B) and adjustable camber plates (15.8, F). A chance encounter with Jon Kaneda of JIC Magic convinced us to try the new JIC FLT-TAR coilover suspension system. But we didn't want the normal off-the-shelf system; no, we wanted the kit that was on the 2007 Super Lap Battle Street Class-winning M1 Evo VIII.
Compared to the 'normal' FLT-TAR coilovers, ours still retain the 15-position adjustable inverted front monotube and monotube rear dampers, independent (from suspension travel) ride height adjustment and upper spherical bearing front camber plates. Where our coilovers differ is the use of spherical bearings instead of rubber in the rear upper mounts and custom spring rates. We opted to go with 10kg/mm springs in the front and a stiffer 12kg/mm rate in the rear to aid with ass-end rotation. A big plus was the loss of seven pounds per front corner with the FLT-TARs (14 pounds versus 21 pounds stock) although the rears gained one pound (12 pounds versus 11 pounds stock).
After installation, we headed to M1 Fabrication & Development for advice on alignment settings. Autocross and road course demands generally require two different alignment setups, but we needed a ballpark to get started. According to the rulebook (15.8, J), we were free to dial in whatever alignment settings we could, using only the parts that we just installed. We aimed for three degrees front camber and two degrees rear camber, with zero inches of toe all around. We hit our camber settings easily (be sure the front stock camber bolt is oriented the right way or you'll sacrifice almost a degree of camber) and ended up with 1/32-inch of total toe out in the rear.
After road testing, we ended up with a street setting of seven clicks from full hard up front and five clicks from full hard in the rear. Make no mistake, this is not the most comfortable suspension in the world. There are harsher cars (the old FD3S RX-7 R1 comes to mind), but Project Evo IX is as stiff as Kaneda warned. This can largely be attributed to the heavy rear spring rates we've chosen, but the Evo needs as much help as it can get to avoid beating up the front tires at speed. If you're concerned about ride comfort, stick with the standard JIC configuration. But if you're looking to go fast, ask for the SCC formula.