Progress! As of this evening, the turbo, manifold and dump are off the car. Everything went quite well, the only drama was having to cut the dump pipe wastegate section to allow the whole assembly to come out in one piece. Some of the nuts weren’t that tight so this may be a timely intervention.
The plan is to have the external wastegate pipe feed back into the main dump where it is visually lined up in the above photo. It currently hugs the gearbox and joins back to the dump towards the rear at a right angle. A set of flanges will be added near the new junction so the entire wastegate pipe can be unbolted to free up room in the engine bay when needed. Improved convenience and flow.
What will be tricky is finding a good place for the bung to be welded on for the wide band O2 sensor. Space is tight in that part of the engine bay.
I did find that there was a significant gap on one side on the manifold to external wastegate junction, with one nut coming loose and falling off somewhere. Some response and power would have been lost from this so it is encouraging to think of the improvement that will be made.
The new turbo is bigger than the old, but not as different in size as the HKS 2510 was compared to the T25G as shown on the turbo upgrade/change page.
I have test fitted the dump pipe and manifold and everything lines up perfectly. The kit came with new studs and nuts, so putting it all back together should be pretty easy. The turbo oil drain from the old turbo might be needed but that is not a concern.
I took off the rocker cover and the VTC assembly has been removed. It should be sitting in the large gap in front of the left cam. This means it was probably rattling and the owner removed it instead of repairing. If my understanding is correct, this means the low/mid range is compromised by the fixed timing, which accounts for my impression of lag since owning the car. The effect on power is shown in the graph below, my engine is stuck on the ‘I’ curve. Depending on the difficulty I could buy a new VTC mechanism and refit it. I could also put in an adjustable timing gear to find a better compromise, but that won’t be happening in the short term.
Not sure of the time I’ll have tomorrow but I may start hacking up the dump pipe or reassembling the new turbo.