by M-P Spierer
The cooling system in the FD RX-7 is widely regarded as its most glaring weakness. Many of the engine's cooling components are constructed out of plastic, the intercooler is wildly undersized, and the orientation of the radiator does not allow for proper airflow to the intercooler. In the next two installments of Project [Rotary] FD RX-7 we tackle these issues by implementing a 100% custom V-mount cooling solution.
Whether it's high RPM, high power density, or for some, high failure rate, the word "high" is regularly used to describe various attributes of the rotary engine. Today we are fighting against the rotary engine's high inclination for dangerous oil temperatures and ignition break-up. This requires significant upgrades to both the oil cooling system and the ignition system...and by upgrades, we of course mean complete redesign.
Designing and installing the turbo setup is one of the most enjoyable aspects of any build. There are many decisions to make when planning out a turbo setup and each decision has significant effects on subsequent decisions. It is a balancing act of desired goals and undeniable trade-offs. Many questions need to be answered like, am I looking to maximize mid-range response or top-end power? And, how much response will I be giving up if I choose one turbine housing A/R over another? These are questions that have different answers for every build. For this RX-7 we are trying to maximize response around a specific power limit without breaking the bank.
Fuel systems upgrades vary drastically and sometimes only a simple pump or injector change will suffice. Other times, like in this project, it seems like every component in the entire system needs to be changed. Recently, in Part 2 of Project RX-7, we covered the engine side of the fuel system, where the injectors, rail, and pressure regulator were upgraded. Now it's time to discuss the remaining fuel system upgrades that we are so eloquently dubbing the "chassis side."
There are three key ingredients for combustion in any gasoline engine: air, fuel, and spark. Parts 2 and 3 of this project will focus on the fuel component of this recipe. Rest assured, this won't be your typical run of the mill RX-7 fuel system.
By M-P Spierer
The 3rd generation Mazda RX-7, often simply referred to as the FD from its chassis code FD3S, is a world renowned platform for both street cars and race cars alike. Combine its weight, suspension geometry, driving position, and power potential and you have a 100% performance oriented machine. While it has become popular over the past decade to ditch the rotary engine and replace it with Chevrolet LS V8 as seen with our very own Project V8 RX-7, this project vows to keep it real with the triangles!.
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