RX8 Tuning Tips

"Renesis Renaissance"

Mazda had great success with the RX7 and proved that a rotary engined car can be fun to drive. The successor came in the form the lovely RX8. It was leaps and bounds better than the RX7 in many respects.

The angular lines, edgy design and interior trim all won the hearts of RX8 around the world. Mazda updated the 13b Wankel engine creating the innovative Renesis rotary engine.

The benefits of a rotary engine include the ability to provide high rpm tolerances and a silky smooth power delivery. Problems though include a lack of low down torque at low RPM but when driven correctly these cars have a lot to give. Standard power figures of around 200bhp from a 1300cc engine really pushes the envelope of what is possible.

Your RX8 tuning should start off with some improvements to the handling and brakes. A big brake conversion kit will really pay dividends and give a progressive brake feel. The car can be lowered around 35 mm. We would recommend adjustable suspension so you can set the damping and spring rates to suit your driver preference.

The engines need to be properly looked after and serviced regularly. Do not let the unusual rotary engine put you off. These are much better than early rotary engines and are every bit as flexible and reliable as a reciprocating piston setup.

The RX8 is just crying out for a turbo conversion and this is probably one of the few "bolt on" options although it can prove expensive. A turbo will raise the standard power to around 400bhp! Sadly in the real world there is a lot more to it than just bolting on a turbo. A whole host of other components will need uprating and strengthening and the mapping will need to be spot on.

The 4 port engines are more suited to turbo charging than the 6 port ones but both conversions require a lot of work and planning and we would not recommend undertaking this unless you have obtained a full kit and have facilities to run a custom map. Obvious power mods for  a turbo RX8 would include a larger front mounted intercooler. The intercooler can suffer from heat soak on long runs so channelling lots of fresh air through this will pay dividends. Power can also be increased with the addition of a larger turbo or a turbo with higher performing internals (a hybrid).

Engine heat build up is a massive problem when adding forced induction and a larger oil pan and even an oil cooler will help address this issue. It would also pay to get the exhaust down pipes coated or wrapped to contain the heat.

Further engine cooling mods will include an uprated water pump and thermostat, and use of a synthetic water cooler additive with some high performance silicone hoses to avoid leaks from higher pressures.

When pushing larger power gains you will also need to uprate the fuel delivery system to prevent the engine from running lean.

We have looked remaps for the RX8 and sport chips without much success. Hopefully RX8 remaps will become available. 

The best option we could find is fitting a full aftermarket engine management system. This allows you to fine tune the timing and fuel delivery for the maximum power gain and this will also allow you to factor in any other mods you have done. On a standard car with an aftermarket engine management system you can see power gains of around 2-5%.

Porting the Renesis engines, if done properly, can have a big impact on the power delivery and torque curve. This is not a simple job though and is only really worth doing if you are already stripping down and rebuilding the engine. Lapping the flat housings and adding high quality ceramic seals are considered important mods here, and dynamic engine balancing will also help you reach higher power gains retaining reliability.

A sports exhaust and induction kit can help provide power gains a little, but in the opinion of TorqueCars members, the standard setup is pretty good and gains are only noticeable high up in the RPM rev range. There are not many 200bhp NASP 1.3 engines out there so you have something special in the RX8 and the nature of the way the engine works means it is ideally suited to hydrogen as fuel! (Perhaps this dream may become a reality one day but for now I guess we have to stick with petrol!) 

Adding a sports cat will also free up a bit more power, on the Renesis these little gains all add up quite effectively.

Reducing the weight of the flywheel to around 9 lb's seems to be a popular choice and does change the nature of the engine quite a bit, but we should add not always to the taste of drivers, try one fitted to an RX8 first before you commit yourself here.

Why not join our friendly forum and swap tuning ideas and share pics of your RX8 with our other members.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Mazda. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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