RX-8 Daily Driver: Tune-Up!


The idiosyncrasies of the rotary powered Mazda RX-8 causes rotary owners to have curious and obsessive compulsive behaviours about their cars. But they love it! For instance, I never touch the gas pedal while starting my RX-8 and, when shutting it down, I always rev the engine to 4 or 5 grand and shut the engine off in the midst of that. Never start the car and immediately turn it off again. You know, like you would if you were moving a normal car around to a spot you can wash it. Instead, drive it around the block. And the now ancient catch phrase often attached to rotaries – drive it like you stole it! Meaning that the car has a 9000 RPM redline and you need to ensure your car sees it. Regularly. Right now I am sure that there is someone out there laughing and saying I could avoid this if I had all of the ECU updates – believe me, they have been done.


Another issue I have with this awesome looking plastic floor – I cannot use a jack or jack stands without first having a wood base down. The plastic would not hold up to the weight and would break. Please note, anytime you're jacking your car up make use of jack stands. Putting your body parts under a car without using jack stands simply isn't smart. (The rubber ball is hanging from the ceiling on a rope. It is for the family Altima – when the windshield and the ball touch, the car is in far enough to close the door while still giving maximum walk about space.)

The fault for flooding lies with the driver. You see, the first time it flooded was when my daughter just moved if to get another car. On and then off. But this was compounded by the fact that for a few weeks she had been trying to turn my RX-8 into a fuel efficient machine by shifting at 3 grand all of the time. Combination – a perfect mixture for a flooded engine. And this second time, my laziness in not doing a tune-up when I should have done so. My faithful readers will know that I have been so busy that I have not finished the tune on my NX GTi-R. I submit this as proof that life has been hectic! The NX GTi-R now has a built engine with CP Pistons, Eagle Rods, JWT cams, Ishihara-Johnson crank scraper, and an awesome Precision Turbocharger.  The final steps of the build will be taking place this winter.


The right tools make any job easier. The extension with the wobbler end allows a bit of an angle. The universal joint ratchet adaptor obviously allows even more. They're helpful when removing the rear spark plugs.

The RX-8’s Renesis engine is a two rotor rotary with four spark plugs – a leading (often referred to as the lower) plug and a trailing (often referred to as the top) plug. The leading and trailing plugs are different thus important to ensure that they are properly located. Fortunately, the L and T are clearly labeled. The ignition wires obviously must be attached in the proper order or you will not have, and I am guessing here, a running engine. The final part of the Mazda RX-8 tune-up are the four ignition coils. These are tucked under the intake but can be removed without too much fuss or need for a contortionist.


You can see the raised 'T' just to the right of the spark plug. This is the trailing plug which, helpfully, is also the top plug. Just below the trailing plug is the Leading plug, which can also be referred to as the lower plug. The trailing and leading plugs are different – it's important to install them properly.

I have purchased my ignition kits from MazMart – they provide a great service and ship throughout the USA and to Canada. With the spark plugs I chose to put a light layer of anti-seize on prior to installation. This part is very straight forward. Installation of the coils is also very easy. Remove a 10 mm nut per coil, disconnect the power source, and the coils are out and the new ones in. There is no set order for the coil replacement, unlike the spark plugs.  The first tune-up I did with the car I got upgraded NGK wires from MazMart. This time around, as I had forgotten what I bought years ago, I got OEM replacements. I like the NGK ones better – it seems to me that they are longer. Not only do I record which ignition wire goes where, I usually have a diagram. I simply do not work on this rotary engine enough to think I know it all. There is an aftermarket ignition coil option from Black Halo Racing. It offers a longer lifespan and improved drivability. It may be an option to consider in the future for my virtually stock RX-8.


I don't know what this plastic thing-a-ma-jig* is, nor did I take the time to look it up. Just hidden by the strut bar is a hose clamp. Remove that and then carefully remove this (if you're not careful, you'll potentially snap those little 90° connectors I spoke about earlier). This allows access to the coils. While it's tight to work on, it is much easier than removing the intake components to get unfettered access.
Right in the centre of the photo you can see coil #1 with the spark plug wire removed; beside it coil #2. Access is a bit tight but easier to access like this and leave the intake components in place.

Before installing the plugs, I took my air compressor nozzle and, one at a time, blew out the combustion cavity. To my thinking, if there is fuel there clogging up the plugs then as much as I can remove then the more likely I will be successful at starting up. I should also mention that throughout this time I had my battery charger feeding the battery. I wanted it to be up to full life when I attempted to start it up. Another option is to use a second vehicle and boost it while attempting to start. That works quite well, however, in my current location charging it was the best option.

*Thanks again to Charles Hill at Black Halo Racing for identifying the thing-a-ma-jig. This is a resonance box which eliminates certain harmonics which arise at specific RPMs. Most a

ftermarket intake kits remove the factory box and accordion hose, which leads to a “howling” sound in the intake system.  It should be noted that the factory airbox flows more than enough air for any rotary engine and the SpeedSource car which was powered by a 20B still used the factory RX-8 intake.

1 comment

  1. I adores the rotary engines, I love the high revs and the chassis designed by mazda.
    the rx8 has always been a great sports car. Balanced and not over powered, and it has real usable back seats.

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