I had a White '85 TC 5-speed and a Back '86 XR4Ti auto.
I got the TC new (lowered), and it didn't take long to discover it was boost limited in 3rd, 4th & 5th. I called up SVO in Detroit and asked an engineer why...he paused, and then said "
to keep owners from raising hell on the streets...". I asked how much boost I could get away with and he seemed to feel that at least 18 lbs. would be fine.
I temporarily mod'ed to hit +25 and went for a ride....the front end lifted and it was hard to keep it pointed in a straight line...as well, the brakes were not up to the job and heat soaked quickly.
Took me a while to find out that the boost cut trigger was due to Ford using a make/break ground. Set it up for 15lbs in all 5 gears, added meth injection and the rest is history. So many tickets...the pilot for the CHP's sniper plane wasn't happy I outran him...didn't even know he was up there. Went thru 3 exhaust manifolds from excess heat...very pretty when they glow in the dark, actually. Chewed up local V8 Mustangs at will. Hated the brakes and solid rear axle.
Ended up with the XR years later...put a TC intercooler in it, but it was an auto, and like the TC, basically a 4,000 Pinto until the boost came up - brakes were never that impressive either, but I still liked that car, even if the top end was only 130. I always wanted the XR's IRS (any iRS) in a 'Bird, so the SC is the best of all worlds for me now. And with the supercharger, I don't have to wait for boost to build