Have you ever wondered what’s going to happen to motorsports when the engines being produced by the world’s carmakers are all choked to death by emissions regulations and fuel-economy requirements? Take the new Honda Accord V-6, for example, which now has the catalytic converters integrated into the cylinder heads. Not exactly a prime candidate to install in a Formula or Touring race car!
Point being, as the global marketplace and environmental concerns continue to shift the focus of OEM engine design from horsepower to hydrocarbons and mpg, there are going to be fewer and fewer engines available for racing series like Formula3 in Japan, which has traditionally used engines provided by Toyota, Honda and Nissan (though now only Toyota makes engines for this series). TODA Racing has recognized this fast-emerging reality and has responded by designing an all-new, high-output, 2-liter, 4-cylinder engine that’s designed to be used in a wide variety of applications, but is especially relevant for F3 and other similar Formula car series where there’s a real risk of the OEM engine supply drying up completely.
As you’d imagine, taking on a project of this scale isn’t something too many non-OEMs have attempted, so to call TODA Racing’s plan ambitious would be a bit of an understatement. But that’s not to say that TODA lacks the engineering savvy or experience to achieve its goal this relatively small Japanese motorsports company (40 employees) has been taking 4-cylinder engines from companies like Honda and Toyota and converting them into high-output race motors for almost 40 years. It’s no wonder then that TODA produces some of the most effective and reliable race-oriented engine internals on the market today, not to mention its other tuning products like coilover kits, headers and ITBs.
Starting with a blank sheet of paper, TODA’s engineers began the design process for their first prototype engine, named the TR-FX01, with the following considerations in mind: light and compact, twin-cam 16-valve cylinder head, stress-mount construction, accessory parts (like the alternator and water pump) at the front bottom of the engine block, and built to a price that suits series like F3 (no price has been set, but something around $30,000 would be typical for a professional-level motorsports engine like this). Other technical considerations included the need for a thermo-fluid analysis of water jackets within the block and head, efficient design and manufacturing using CAD/CAM, verification that all processes from planning, design, manufacturing, assembly and dyno- and drive-testing can be completed in-house, and the design and manufacture of the engine wiring harness could be completed in-house.
Starting with the engine block, TODA’s engineers realized that although a cast engine block is best for high-volume production, since the TR-FX01 would be a prototype, the block was machined from 2017 aluminum using a 5-axis-machining center. The water jackets were designed using thermo-fluid analysis to verify cooling equalization throughout the entire block, and the block’s thickness and rib layout were selected to ensure a high level of rigidity, which is particularly important since the engine is used as a stress member when mounted in a Formula race car.
The TR-FX01’s bore and stroke are both 86mm, creating a square ratio that’s well suited to continuous high-rpm running in a race car. There are provisions on both sides of the block so that it can be installed in a road car, too say in a historic GT or Touring car or even a street car if you’re crazy (and rich) enough, the cast iron cylinders ensuring a wide range of potential applications. Perhaps the most unique feature of the TR-FX01 engine is that its chain-driven accessories (including the oil pump, water pump and alternator) are built into the block and completely enclosed beneath the front cover. There is also a dry sump oiling system in place, using a sand cast pan that has been stress analyzed since it, too, is part of the mounting system when installed in a Formula car.
The cylinders are stuffed with A4032 forged aluminum pistons, the dome design having been derived from TODA’s extensive experience in this area. Focusing on durability as well as weight, the piston tops look more like a turbo design, with a low dome, but thanks to the compact combustion chamber the compression ratio is 12.5:1. Piston weight is 250g and the wrist pins are 20mm in diameter. The connecting rods are also forged, using an I-beam design made from chromoly steel, TODA’s preferred material choice for all its racing engines because of the material’s high tensile strength and light weight. Con rod length is 142mm, and they weigh in at 500g each. TODA opted to use an existing production crankshaft for the prototype engine, but in the future other crankshaft options will be available, depending on the purpose and application of the engine.
The cylinder head, sand-cast via rapid prototyping, uses four valves per cylinder, with 35mm valves on the intake side and 30mm valves on the exhaust side. Valve angle is set at 29 degrees in total (14 degrees on the intake side and 15 degrees on the exhaust side), as determined by TODA’s computer simulations. The head uses fixed valve timing (no VVT) and is designed to have excellent throttle response from high-airflow velocity (further enhanced by the carefully tuned 50mm individual throttle bodies). To allow the engine to have a higher knock limit, TODA used its bronze valve guides and beryllium copper alloy valve seats for improved durability and heat conductivity. The valve springs are made from a super-high-strength material with progressive pitch, while the camshafts chosen are 285/12mm on the intake side and 280/12mm on the exhaust side. The cams were selected to achieve the target power output, and they are hollow for reduced weight, just like TODA’s well-known VTEC Killer camshafts.
Having started the manufacturing process for the prototype engine in January of 2008, the TR-FX01 was completed in April of 2009. After an engine-firing ceremony, dyno testing began and then the engine was installed in a F3 chassis for track testing at the Okayama International Circuit in August of 2009. Early testing led to adjustments to valve timing, intake trumpet length, and exhaust valve specs, with final ECU tuning resulting in a rev limit of 9000 rpm and peak power production of over 270 hp and 177 ft-lbs of torque.
With a total engine weight of just 95 kg (not including the clutch), TODA Racing has certainly succeeding in meeting its goal of a lightweight engine. With initial power production of over 270 hp without any start-up or reliability issues to date, it would certainly appear that the engineers at TODA have also succeeded admirably in the performance department. In fact, a full teardown inspection revealed no abnormal wear on the pistons or cylinder walls. Given just how promising the power and reliability appear to be, we certainly hope that TODA puts the TR-FX01 into production soon, ensuring the future of important racing series like Formula 3, a well-established training ground for future stars of F1 and Super GT. In fact, with a destroking to 1.6 liters, the TR-FX engine could even be configured to meet the ’13 Formula 1 regulations.
The TR-FX01’s bore and stroke are both 86mm, creating a square ratio that’s well suited to racing or street use.
Final ECU tuning resulted in a rev limit of 9000 rpm and peak power production of over 270 hp and 177 ft-lbs of torque.