Hey guys, I'm looking to buy my first rx7 and I found one that's rust free and runs well. My only issue with it is that it has the stock 4 lug hub and I would like to convert it to 5 lug to give myself more options when it comes to wheels. After doing some research I found that converting the front wheels was as simple as hubs, rotors, calipers, etc. However converting the rears looked to be a complete subframe replacement/conversion. I was wondering if this still applies in 2018 as the forums I got this info from were 10 years old. If so how difficult/expensive would the subframe swap be?

 

You don't need a replacement subframe for this conversion. For the rears, you only need the 5-lug hubs, vented brake rotors and calipers. You will need a hydraulic press to replace the rear wheel bearings and seals as the old bearings will be destroyed in the process. An auto parts store might be able to do this for you. To make the job easier, you might want to search the web for a used set of 5-lug tri-axial floating hubs. Here's a youtube video that might help:

 

All you really need is the solid 5-lug rotors, your old calipers will work fine.
The only difference between the two systems is the slightly wider vented rotor and the matching caliper, also slightly wider.
The rotors are the same diameter and the calipers all take the same pads and rebuild kits- they are functionally identical.

Oddly, the vented rotor seems to be easier to source, which is why I went with the full conversion.