What is the difference in a S4 and S5? and how can you tell by just looking at them? I know the Series 5 is better I've read a little on them but can an Series 4 be equivalent with minor modifications?

 

 

You ******* fail again. Did you not read the other ******* post you made about the same question? It answered your question on how to tell them apart visually. Not to mention the FAQ answers every single possible question about the difference.

Here, I'll even give you the link to the FAQ. I suggest you READ IT.

https://www.rx7club.com/forum/showthread.php?t=494667

and

https://www.rx7club.com/forum/showthread.php?t=642372