The Ronin Speedworks kit will allow you to safely and securely mount the robust Ford 8.8 (2007-2010 explorer case) into your FD3S Mazda RX7.
The Ford 8.8 is widely used and regarded as a great bang for your buck rear end. It has many many gear options available, which makes it not only very affordable, but also very flexible! For example, you can do a fully built rear with Detroit TrueTrac LSD with gears for only $650 in parts!!
This ford 8.8 kit will only work with a 2007-2010 Ford Explorer 8.8 IRS case. This case is the cheapest and easiest to find! These junkyard rear diffs can be found at your local junkyard for $130-250. Pretty cool, right??!! This kit will allow you to bolt in this strong, affordable rear end kit into your Mazda RX7 FD3S. The kit is 100% bolt in, but does require welding of the front support to your stock subframe. It is best to find a local welding shop to do this, as shipping subframes is cost prohibitive.
There are three options for axles.
The first option is sending me your stock axles outer stubs as cores which will be converted to work with the 8.8. The only part that will remain stock is the outer stub that fits in the wheel hub. The stock FD3S RX7 outers are actually pretty strong. The bar will be upgraded to a level 5 DSS bar and you will get a set of billet stubs for the 8.8 rear. This will save you some money over the pro axles, but is not recommended for the hardcore drag racers.
The third option is the Driveshaft Shop Pro-Level 1400HP axles, which include a heavier bar and also upgraded outer wheel hubs. The hub is a weak link in extreme power cars, so these will be only for the really big power guys.
This FD3S RX7 8.8 Kit Includes:
Axles are a 2-3 week wait time. Aluminum or Carbon Fiber driveshafts can be made for any transmission combination. Just let me know what transmission you are running in the order notes (I may require measurements)!
You can have a local shop mustang/domestic shop build your junkyard 8.8, or you can have me build you one to your specs. In the dropdown options, you can select a GR built rear which includes a Truetrac LSD, and gear ratio of your choice, and all new bearings and seals, it also includes me sourcing the 2007-2010 explorer case. For the T56 Magnum / GR series close ratio transmissions I recommend 4.10 to 4.30 gearing.