Because I got bored. It was an awesome drive, but was just on the hunt for a little more.
Driving the cars I build isn't really where the fun is for me. I enjoy building them, and tinkering with them. My '023 hybrid build was "finished", and couldn't really go much further, so I wanted something new. Add into that the fact that the last trackday left me with a missfire, which was diagnosed as a valve issue after taking the head off, it made sense to upgrade while the engine was in bits.
Mylo had an '064 for sale with the 1.8t adapter for a price which (even with selling the '023, manifold, lines, TIP and downpipe, for what I consider good money) left me with a better turbo, and £300 in the bank, meant the upgrade was pretty much "free" using the good old fashioned man-maths calculator (£150 for lines, which left me £150 for the fabrication work, which was easily doable).
Unfortunately I didn't bank on the £750 it has cost me for the uprated exhaust valve springs, the inconel exhaust valves, and the porting and polishing!
Once I finish this build, I will probably end up moving on to another turbo, lol! I was the same as a kid with Lego...the minute I had built it, I took it apart and made something else. Playing with it is boring; making it is where the fun is for me. I enjoy a challenge... and part of that is why my engine bay looks like this at the moment, while I do an engine bay tuck (temporary small port head to mock up with):
Serves no purpose whatsoever, is taking an absolute age, and seems to be costing a lot more than it should...but to me, its interesting, and I enjoy a challenge. I like doing stuff differently. I want people to be intrigued by what I'm doing, and hopefully this will happen soon enough with this build.
...so that's why I'm not running the most-awesome-hybrid-K04-in-the-world anymore. Not because it was crap or unreliable, but because I am a sad-act who has nothing better to do with his time than tinker with his car! After all...if I wasn't playing cars, I'd have to clothes shop with the woman...and nobody wants that!