The heart of this kit is the Mazda RX8 A/C compressor which weighs in at 8.57lbs compared to the stock FD’s A/C compressor which weighs 13.0lbs. This is a reasonable 4.43lb weight reduction from the front of the car.
The RX8 A/C compressor is a much simpler and more compact “Scroll” design than the FD RX-7’s older and less efficient “Poppet Valve & Swash Plate” compressor that generate more heat in the way it functions.
The RX8 compressor has a single 2-wire connector (identical to the OEM igniter connector) while the FD RX-7 compressor has an integrated 2-wire connector that goes to a single-pin white connector (hidden in the photo). The JP3 kit comes with an adapter cable that makes this compressor a truly plug-and-play install.
The RX8 compressor also has a 4-rib pulley vs the 6-rib RX-7 compressor. The FD RX-7’s Power Steering & A/C pulley belt is 6PK-1045, while JP3 Motorsports offers a 4PK1015 for OEM pulleys, or a shorter 4PK1005 for underdriven main crank pulleys (Banzai). JP3 has hundreds of these kits out there and the narrower 4-rib pulley has been proven to be reliable for the street and the track.
The RX8’s 90mm compressor pulley is significantly smaller than the 126mm stock FD compressor pulley. This means that the stock FD compressor rotates at 89% of the speed of the crankshaft, while the RX8 compressor spins at 122% the speed of the crankshaft. This is a significant difference, but keep in mind that the RX8 has a 9,000rpm factory redline and this compressor was designed to handle it (on top of being a more efficient design); while the factory redline for the FD RX-7 is 8,000rpm.
We first removed the factory compressor from our 13B REW block.
