The original 175/70SR-14 Michelin MXLs definitely limited the '84 2.3s maximum grip. At about 10-15K miles or so (mid-'85) I replaced them with a set of 195/60HR-14 Phoenix Stahlflex 3011s, which were probably the best street tire you could buy back then. They were commonly used in showroom stock racing and autocross, and I also ran them in size 205/60H(and V)R-13 on my Cosworth Vega. I had one set that was worn that I used for track events and another set mounted on another set of OE wheels for street driving. Once I worn out the track set I'd use the "broken in" set for track events and buy a new set for the street.

The Phoenix dramatically improved the 2.3's maximum grip. Its limits were about the same as the CV, but without the bone jarring ride. The Phoenix were just about worn out when I sold the car at about 50K miles in 1988, so I installed a new set of 195/65HR-14 Continential CH51s just before I sold it. The 195/60s were a little short and increased speedo error, but the 195/65 size had about the same revs per mile spec as the 175/70s.

I still have a set of Phoenix for the CV that never saw the track, but usually just keep the Toyo Proxes RA-1 DOT legal racing tires installed that I finally switched to in the mid-nineties when my supply of Phoenix dried up, and at that point the DOT legal racing tires had pushed grip well beyond what the Phoenix could supply, but their steel reinforced sidewalls make the CV ride like it has wooden wheels on anything less than fairly smooth pavement. That's the price you pay to have roller skate handling on a car with much less torsional stiffness and a much less sophisticated suspension.

Duke