S5 Turbo unit
 

I have a S4 13BT and want to upgrade the Turbo to a S5 unit.
What other parts will I need to make the S5 unit go on my engine i.e S5 exhaust manifold, S5 oil lines, S5 front cover ???

Cheers

Don't need the front cover. Just swap the oil lines from the s4 to the s5 and it'll work just fine. You need the exhaust manifold for the s5

What are the differences between the S5 turbo and the S4 turbo?

s5 turbos are slightly better at controlling boost. You can do a bit more for modding without having the turbo creep to 15 psi.

Thats it really. You will still benefit greatly by porting an s5 turbo so I suggest you do so with your mods.

If its power you are looking for then its power you will lose by having less boost with an s5 turbo.

hmmm...i'm in the middle of the swap right now. i have the S4 turbo/mani out but have yet to put in the S5. the oil lines are different? i never noticed.

Well, my S4 turbo is ported and it holds boost steady at .5bar with my current mods. I need boost control!

thats strange, becuase in 4th gear i'd hit 1bar with my mods on a stock s5 turbo

Well, your wastegate isn't ported, is it? Mine is, so that's why my boost is so low. Before I ported my wastegate, I'd hit 1bar too. :p:

Same here i have an s5 ported and i get max 10psi and thats if i really try. If i start from a stop and just floor it at redline i only get 6psi, so so far its better compared to my old setup in which i was hitting 15psi ( which is very bad!! )
You say this like its bad, keep in mind these turbos are not ment for 15psi worth of boost or anywhere near it. In my opniion its good for the turbo to boost low that way you have more control and less likely hood of detonation. Its just a whole lot safer. You want more boost upgrade the turbo completly IMO.