These are the Unorthodox Racing lightened/underdrive pullies. The larger one in the upper-left is for the crank, the bottom for the water pump and the top-right for the alternator. There is no replacement for the air conditioner compressor or the idler. The reason to replace these is to reduce rotational intertia, which helps the engine to spin up faster. These pullies slightly underdrive the water pump and alternator as well, so losses in power to the accessories are slightly reduced too. However, the interia reductions are the big savings. Weight of the parts:
| Part |
Stock/Mazda
|
Unorthodox Racing
|
| Crank Pulley |
27.8 oz
|
11.5 oz
|
| Water Pump Pulley |
10.8 oz
|
5.9 oz
|
| Alternator Pulley |
5.7 oz
|
2.1 oz
|
To install the pullies, you need to take the airbox out of the car to get access to the water pump and crank. The engine in the RX-8 sits so low you won't be able to reach them otherwise. The parts went in fairly easily. The crank pulley was the most difficult as the fit is very tight and any rust on the crank mating surface or nose will cause interference. Getting the old crank pulley off was a pain -- I ended up using a pair of Vice-Grips and a hammer. Make sure to slather everything in anti-seize to prevent dissimilar-metal corrosion between the aluminum pullies and steel engine. Unorthodox supplies part numbers for new belts, which are not included in the kit. They are Gates K040292 and Gates K050316, which you can get at amazon.com for about $11 each.
This is a top view of the REVi after installation. There are a lot of parts to assemble for it! My only problems with it are that some of the bolts that were supplied were too long and needed to be cut, and that mass airflow tube (blue, about middle of the picture) was poorly anodized (lots of oxidation coming through). Directions supplied were very thorough and were easy to follow.
Slightly different view of the REVi with the cold air intake scoop sticking out below the bumper bar.
Better front view of the REVi cold air scoop under the bumper bar.
The blue item in the middle of this picture is the oil temperature/pressure adapter for the gauge set. It is installed under the oil filter. I had two problems here. First I smashed the o-ring supplied with the adapter, so it wouldn't seal and I ended up with a pretty good leak the first time I turned the engine on. If you need to replace the o-ring, you can get it from McMaster-Carr supply (AS568A Dash Number "035", made of BunaN or Viton). I probably could have had Racing Beat send me a new o-ring, but I was on a tight schedule so ordered them with quick delivery. Second, I dropped the compression sleeve for the oil pressure line on the floor and lost it. I ended up finding a new one at a local auto parts store (it's a 1/8" sleeve, if you are interested).
Water temperature adapter in blue in the middle of the picture. This is installed on the passenger side of the car up against the firewall. One unclear item here is that the temperature sensor will fit into the blue adapter and screw down tight without the supplied NPT-to-Compression adapter. This is bad for 2 reasons: first, tightening the sensor down will smash the sensor into the back of the blue adapter, possibly damaging the sensor. Second, with the sensor smashed into the back of the adapter, the outlet is cut off and will prevent coolant flow, which is bad for the engine.