The Mazda rx-7 and now rx-8 are well known as very capable sports cars. The rx-3 led way to what became the rx-7 powered by a 12b rotary engine. The 12b stands for 1.2 liters of displacement as the 13b stands for 1.3 liters. All rx-7’s came with a rotary engine and were 2 seater cars. The rotary engine works completely different than a conventional piston otto cycle engine.
The two stroke exhaust pipe is a very important tuning tool of a two stroke engine. A stock two cycle engine is usually tuned to make reasonable power across the power band. Aftermarket pipes are called expansion chambers because of the way the pipe expands in the center. A 2 stroke engine has a very strong exhaust pulse that occurs as the piston passes the flat top of the exhaust port. The quick pressure pulse moves quickly down the pipe and creates a shock wave as it exits the end of the pipe. Part of this strong pulse wave travels back up the pipe and if timed correctly bounces off the piston as it travels downward.
The fiero is a popular car to modify. Many owners and kit car enthusiasts alike would like to have a little more power out of these vehicles. There are fiero performance upgrades out there but when people are not aware of them or want a lot of power they install larger engines. The fiero came with two engines, the 2.5 liter “iron duke” or “tech four” four cylinder engine was the base engine. The performance engine was the 2.8 liter v-6 engine found in the gt cars. The 2.5 liter engine made 105 horsepower and 135 ft/lbs of torque stock. The 2.5 l engine has been used in the nascar touring car series and was known as the “super duty” engine. The 2.5 liter has access to special high port aluminum heads which also needs a special intake manifold and the use of a carburetor instead of the stock throttle body fuel injection. There is also a cosworth produced 16 valve head which could produce a great deal of power. Both of these are costly alternatives and may cause problems if you live in an area where emissions tests need to be taken.
