I realize that there will likely be little interest in this setup, but here goes...
I bought a new set of rains for the track car. Toyo RA1 255/40/17 on Apex ARC-8 17x9.5 et 35. Square setup. Decided to use the street car to scrub them in. Mounted without a spacer in the front and using a 15mm spacer in the rear (so effective et is 20). Being a shorter tire than the stock staggered 225/45/18 and 255/40/18 rub was no issue.
What I didn't expect was how much better the car drives. Immediately noticed how much more nimble the car felt. The reduction in weight, inertia, and circumference made a huge difference. Rear gearing is effectively 3.77 from 3.64 (according the DiffsOnline gearing calculator), so big improvement in acceleration. Being square, and with 100 wear rated rubber, the front turn in is also markedly better.
As for appearance, well that is of course subjective. Front looks better with the meatier tires. Rears don't quite fill out the wheel well. I may just keep these on for a while, the car drives that much better...
