Turbochargers function by utilising the otherwise wasted exhaust gases to produce a compressed air “boost” back into the combustion chamber via the intake. A rotary engine has an extremely hot exhaust flow which contains a large amount of thermal and kinetic energy – perfect for driving the turbine within a turbocharger.

Mazda did a very good job specifying the turbocharger systems on their OEM RX-7 models, however there is always room for improvement as mechanical and technological advances improve the parts and sub-systems to enable better efficiency, reduce turbo ‘lag’ and increased horsepower.

At RotaryMotion we have extensive experience in modifying and increasing the performance and reliability of turbocharged and supercharged rotary engines. We also supply and fit turbocharged or supercharged conversion kits for the RX-8 and normally aspirated rotary models.


1986-1992 Second Generation

RX-7 (FC3S) Upgrades

Both S4 and S5 versions can be modified for increased performance including high-flow exhaust systems, wastegate porting, boost increase, upgraded intercooler systems and more modern replacements for the OEM Hitachi turbocharger.

1993+ Third Generation

RX-7 (FD3S) Upgrades

In 1990, Mazda launched the 13B-REW engine in the Eunos Cosmo before launching 3 years in the final generation RX-7. Exhaust upgrades, Intake & ECU modifications, Turbo and Intercooler upgrades, and auxiliary enhancements such as aftermarket knock sensors, fuel system, and electronic boost controllers.

Normally Aspirated Engines

RX-7 & RX-8 Normally Aspirated

At RotaryMotion we can help you source or provide all the turbocharging components, modify the engine internals to handle the increased stresses of boost, and install all the necessary wiring, intercooler systems, and engine management upgrades required to run efficiently and effectively.

Forced Induction


A supercharger is a belt or chain-driven compressor that creates a flow of pressurised air, fed directly into the intake. This "boosted" air fills the compression chamber with more air molecules that a normally aspirated engine whilst the combustion process remains identical to a normally aspirated engine.

Modern superchargers are generally simple devices and are capable of generating high numbers of engine horsepower. Their torque output is immense and essentially there is no throttle 'lag' or delay. Boost production is immediate and very linear from idle up to the redline. However they are generally not very efficient and require a relatively large amount of eccentric horsepower, between 15% and 50% to drive the blower sufficiently enough to create an adequate cubic feet per minute (CFM) increase. Because of this, supercharged rotary engines rarely exceed 300whp without really pushing the levels of boost

Cooling the pressurised air can also be a challenge with some systems (such as Pettit) using a liquid-to-air heat exchanger to combat this. Belt-drive superchargers can also stress and distort the front shaft extension of the eccentric shaft, more commonly on older rotary engines where their thrust bearings are smaller and cannot resist the increased loads.

Superchargers can be excellent performers but come at the cost of efficiency. Whilst If you want the most efficient form of forced induction, you should consider a turbocharger.

Find out more
Mazda RX-8 Widebody in Orange
Mazda RX-7 FD in Pearlescent Flip paint with Vented Bonnet & Splitter

Forced Induction


With a normally aspirated and even supercharged engine, a significant quantity of combustion energy is wasted through the exhaust at the end of every combustion cycle. A turbocharger works by harnessing this 'waste' energy and redirecting it through a turbine to power a compressor. All the benefits of a supercharger, but without the huge eccentric shaft power drain.

Once generated, the pressurised air is then typically passed through an intercooler to reduce its temperature before being directed to the intake manifold. A wastegate is used to control the amount of boost pressure created to help prevent engine detonation.

Larger turbochargers suffer from a delay in the build up of pressurised air otherwise known as 'lag'. This delay in the spooling of boost pressure caused by wheel inertia is a common drawback of turbocharged forced induction.

Whilst simple by concept, a properly designed turbocharged engine can be very complex. Care must be taken in not only selecting the right components but also ensuring the rest of the engine is evenly matched to the turbo. By under or over specifying any of these components the result can actually be poor engine efficiency, weak power production or even detonation.

Find out more

No Hidden Extra Guarantee

Our NO HIDDEN EXTRA GUARANTEE ensures you only pay for your chosen package. If, once your engine is stripped we find you need internal parts including Rotors, Rotor Housings, Engine Plates or the e-Shaft, we will replace these at no extra cost!

**FREE Recovery

At RotaryMotion, we offer a FREE vehicle collection/recovery service within a 100 mile radius when booking your vehicle in for an engine rebuild.

Please note: We cannot be held liable or responsible for your vehicle prior to collection. This includes vehicle taxation, parking charges and/or subsequent fines.


About us

Customer Reviews

So glad I decided to bring my RX7 fd3s to Rotary Motion!! Quick rebuild turn around with constant updates on progress, professional job done and a really nice genuine bunch of guys. Would recommend them to anyone and couldn’t have asked for a better service. Thanks again for all the hard work the guys put in and looking forward to coming down again for more work!

Tom B.

Having chose RotaryMotion for the development of my RX8 NA race engines I’ve been astounded by the support, technical knowledge and abilities of the team. Having used lots of engine ‘builders’ in the past I wouldn’t trust my rotary with anyone else!

Antony W.

Very nice people to deal with, quick turn around, expert advice, excellent prices, my RX8 is running 100% better than before! I had the silver package engine rebuild with a new clutch. I’m really pleased with the work from Rotary Motion and will deffo use again and recommend to anybody who owns an RX! Thanks for everything!

Jack M.

Since getting into Rotary Chris has always been my go to guy. When I had the RX8 he was who made sure I knew how to look after the car, now on my second rotary an FC convertible. Correctly diagnosed a fault with the car that another garage had missed. Chris is a amazingly knowledgeable guy who works magic at what he does.

Aaron J

Google 5-Star Reviews