i ran a/c when i 1st set up my w2a.  i converted a a2a core into my heat exchanger and it works very well. 
 

good luck. e51 bits and pieces are hard to come by. 

There are plenty of c52s. May as well canibalise it.
Good idea going for the e series. Should be strong enough for your setup.

I will use the C52 bits if I have to but I am not sure that the C52 mounts for the cables and engine will work either.
We will find out when I start swapping things over.
I am trying to keep everything neat and factory as I can. I know that is crazy talk when I am strapping a turbo to the side of the of the engine but if the fit out looks like the factory did it I will be happy.
Interesting comments about the E51. I am hoping the E58 with the slight lighter internals might be a good balance between the two boxes. The ratios seem to be a bit better for a more powerful motor. The E58 is supposed to have a LSD as well which I really need after doing the Ground Control coil over conversion - I always lift the inside wheel round corners now. ( I am thinking I got I may go back to Eibach coils on standard spring mounts)
Pete

Just doing fiddly little bits
Like

Heat shield for the turbo and dump pipe. Both are really close to the cam box here and hopefully this will avoid heating up the oil too much. It will also stop the cam angle/ignition trigger cooking.




Intercooler brackets out of some steel off cuts I had around. One bolts to the back of the inletcam box, head and inlet manifold. The other bolts to the gear box. Once it is all bolted in and connected to the turbo the intercooler is rock solid. So solid I am going hang the coil packs off it.
I have made brackets out of 12mm x 6mm rod but I am going to need to get someone to weld them on. I tried alloy brazing but heating up an intercooler with a gas torch was a no go - it sheds heat faster than I can put it in.


I did manage to braze on some hose barbs on to a blanking plate for the factory cold start set up. They are not pretty but the hose fittings will let me connect up the Haltech's idle air control valve into the same ports in the throttle body as the original cold start.


I also made up a new throttle bracket because the original set up was in the way of the turbo. It's a little rough but it will clean up with a grind and a coat of paint. I haven't drilled hole for the cable yet.
I have also started on the wiring harness no pics but we have all seen a messed up wiring harness.
I will start pulling the engine out next weekend.
Pete

awesome!!!  thanks for the updates man!

Ok, so now i have done it.
I have a couple weeks off work and I am trying to up the pace of the swap and while drilling the C52 selector shaft to fit the E58 I completely cocked it up.
The brilliant idea of making a drill guide to drill the hardened steel selector shaft only came to me after drilled the new roll pin hole well off to one side. (Have a look in the pic how far off centre the bottom hole is on the RH shaft)
So now the only selector shaft I had is useless and I am chasing another one
Can anyone help me out?
Ideally a full selector set up from an E51 would solve all my issues but so far I haven't been able to find one.
But a C52 selector shaft will get me out of trouble 

Dimitriske - I always thought the same thing - that a high mount turbo wouldn't fit in but there is a surprising amount of room. The other good things are that the A/C still fits, the stock oil filter/cooler set up can stay and the turbo drain is a long way above the sump. I will make an extra effort on the heat shield on the firewall just to be sure because there is some weird fuel vapor separator that runs up the firewall not far from where the turbo sits. (Does anyone know if you can get rid of this thing?)
I also like that the manifold is a twin scroll set up that separates cylinders 1 and 4 from 2 and 3. I would like to get a twin scroll turbo to match but finding a twin scroll T3 with an internal gate(s) in a small enough size to suit my motor seems impossible.
P
 

Wow I would have thought a 2560 would fit. The manifold puts the turbo a little more toward the back of the engine so the turbine side lines up with the plastic shield and the compressor sits behind the back of the head. The turbine housing is also a HKS part so it may have been made to fit the application - which is a bit of a worry if I need to replace the turbo. The turbine housing is also really close (10-12mm) to the cam box which may have freed up some space compared to normal high mount manifolds. It also is why I have extended the heat shield in between the two.
Not sure where the waste gate actuator is going to fit though.
P