Powerflex Mk4 - Non
Join Date: Jul 2011
Location: United Kingdom
Here is a summary of the turbo build details via Adam @ TDi:
The original turbo was in a fairly poor state with the shaft had broken and the compressor end (compressor wheel, seal plate and compressor cover) all fairly badly damaged as a result. The turbine end (turbine wheel obviously and VNT cover shroud) were also badly damaged and not to be used again.
Adam swapped over all the damaged bits for genuine Alfa 2056 replacements from a spare unit he had in stock and got them all cleaned up. All the consumable parts (nuts, bolts, o rings etc) were replaced along with the thrust kit and journal bearing that were all replaced with the best quality items that are available. The turbine side twin seals were replaced with racing stagger gap items so there should be zero chance of any oil seepage even with a large diameter or low back pressure exhaust systems
The compressor wheel was upgraded to the latest technology 5 axis machined from solid billet item. The advantage of this over standard is that although it is the same diameter and inducer size, it uses extended tips and has slightly taller blades meaning it can flow and deliver the air a little better. Being that is is manufactured from aircraft grade Aluminium the nose, rear hub and core cone can be made slightly smaller reducing the weight slightly to keep spoolup keen.
The CHRA was assembled and sent out for VSR high speed balancing, and also the VNT mechanism (stop screw position) was calibrated on a flow bench.