The History of the Z from 240Z to 370Z

With the immense popularity of the first generation Z, few changes were made to the model until 1974 where the 2.4 liter engine was increased to a 2.6 liter, dubbed the L26. We would have expected that a motor with higher displacement would have created more output, but thanks to US emissions that lowered the compression ratio and retarded the ignition timing, the 260Z lost 11 horses.  Compliance with more stringent US market safety requirements resulted in a performance sapping weight gain of about 250 pounds. This disappointment only lasted for one year, and in 1975, the 280Z was introduced.

The 280Z received an upgrade to the Z line, replacing the SU carburetors with the Bosch L-Jetronic fuel injection system and a displacement increase to 2.8 liters which contributed to the horsepower increase of 149.  The larger engine was designated as the L28. This model was never sold in Japan, although it was a huge success in the states. Like is predecessor, this model was left nearly untouched for the next two years until 1977, where the 5 speed manual transmission was added as an option to the product line.