The Testarossa received minor updates throughout its relatively long production run, and then a major update for the 1992 model year to turn it into the 512 TR. Virtually every system of the car was substantially re-engineered, largely with the goal of addressing complaints that the original Testarossa had forgone a little too much of the visceral excitement that should define a Ferrari. The engine was changed from Bosch CIS to Motronic, the valves enlarged, and the compression ratio increased. The exhaust system was also redesigned and the resulting engine gained approximately 50hp and a broader power curve while also becoming dramatically more responsive and sounding much better. The engine was also moved forward and down in the car, a significant enough change to improve the weight distribution by one percentage point at each axle. The suspension was also revised, the steering ratio quickened, and lower profile tires fitted to go with new 18 inch wheels, an increase of two inches. The brakes were also enlarged and fitted with cross drilled rotors.