Series 4 vs Series 5 differences

I have S4 TII and i might get cheap S5 TII with blown motor but very nice paint.

Question :

If i will take my S4 TII motor+clutch+flywheel and S4 TII ECU and harness, could i use it without any problems in S5 body?
Transmissions are same, there should be no problem, engine harness and ECU is what i am using still same, its just question if S5 in car harness plugs into S4 ECU

ECU does have 3 plugs, 2 are engine harness which i am using still same, question is about last one - in car...
And other few plugs in passengers foot area which plugs together.
Or should i use manifolds/injectors and harness from S5 and just swap block itself? Turbo on blown S5 car should be fine.

 

Or if i will use complete S5 manifolds, S5 ECU, S5 harness, S5 turbo, could i just leave electronic OMP unhooked and run premix ?

 

i have S4 TII and i am getting S5 TII with blown motor

I will swap all things which are better from my S4 to this new S5.

Anyone could list parts which are better on S4 TII than on S5 TII ?

Differential?

 

You can swap the diffs, but I prefer the S5, since its lockup charactaristics are more predictable, IMO.

You can use the S5 manifolds, but they won't work well without some serious port-matching.

The AFM will wire up, but for minimal (if any) gain.

The S5 turbo is preferable. The S5 intercooler has a slightly bigger inlet, too. Use it.

The S4 compressor outlet is slightly smaller, but it's metal. Keep it.

The S4 water filler neck is metal, and therefore preferable, but you have to retain the S4 water pump, water pump housing, MOP, and radiator to use it. I prefer the S4 versions of all of that stuff anyway.

The S5 electronics are better - use them. Keep the MOP connected, but tuck it out of the way if you use the stuff from the above.

The S5 tranny has a 1st and reverse synchro. I prefer its feel, though there's not much difference between the two.

The S5 car will likely have ABS. The complete non-ABS braking system will bolt on. If you can get ahold of an N/A brake booster, use it, as it provides less assist and better feel.

That about covers it. If you're rebuilding, use the S5 block - it's got more iron around the dowel pin area and it's got lighter rotors. That would be a good time to use the S5 manifolds, too.

Brandon
BR7 Racing

 

ok, i have car here, need to drop my S4 block in S5 car.

i want to

use S4 block, s4 lower and upper manifolds, S5 throttle body and turbo, S5 acessories (PS) and S5 stock mount intercooler

i have my S4 block prepared for premix, no oil injectors....i want to keep S5 full loaded, pretty much stock....i will have straight-thru exhaust, no need for emissions, but i want to have perfect idle anytime....

question nr.1
does S5 TB fit on S4 upper intake manifold? (seem like it will to me, but i have not removed it yet)

question nr.2
what from emissions i could remove and still have good idle with PS and AC? what vac lines to run where then?
should i keep rats nest or ditch everything besides boost-duty solenoid?