4 lug to 5 lug conversion?
 

First off, is it better? My friend said more lugs = more breaking power and overall handling.

Second off, what exactly do I need? Just the rotor disc or does the whole cross arm, cv axle and everything need to be swapped?

Third off, how much is it going to cost, minus labor? and if I can bolt up the transmission to the car, is this a difficult job? If drilling is required, is it port-precision drilling?

To be honest, I'm not even sure you're talking about an FB RX-7. The rear end is a solid axle. No CV's, cross arms and such. Although I feel you may have meant control arms.

But to answer your question, by changing the bolt pattern you can use RX-7 TurboII brakes which are larger and have 4 piston front calipers. A huge step up from the standard single piston brakes and tiny rotors. I love mine. This necessitates the use of larger rims and tires, 15" rims being the smallest you can go. Also opens up the tire choices since there is next to nothing available for a 13 aside from slicks or all season tires. No in between anymore. The flip side of that coin is the one company that did offer a conversion kit has somewhat fallen off the map. However all is not lost. You can swap to GSL-SE brakes which gives you 4x114.3 bolt pattern. Search around, there are tons of threads on that subject. Tons of rim options with that pattern and a set of pads, stainless braided lines and good fluid will go a long way for a street car. The bolt pattern itself has no bearing on performance, it's what it allows you to bolt up to the car that changes the game.

And you don't change the transmission... What car are you talking about?!

I think I got my answer already, thank you very much though!

https://www.rx7club.com/1st-generati...rsion-1058765/