thats great to hear malone. Glad you decided with the diesel roots ( I can't do gassers anymore either...my last, a 8v Lysholm Stg 4 corrado) bored me too after the motor was done, not to mention...tried to kill me
) I chose my diesels as more important for all the same reasons. I've built several 1.8 turbos, for friends though... never was much into the feeling because I've always had a diesel since I was able to drive.
You must be lucky in your IDI TD parts around you then because around here they are scarce, and getting harder and harder to find parts for. I have at least 2 emails or IM's on either the vortex or through thesamba regarding information about whether my 30k rebuilt TD IDI that I had is still for sale. Which its probably by now i hope found its way into the vanagon the buyer bought it for. I hope, with my modifications and rebuild that it serves him many useful miles and an extra boost over stock hp when he goes to turn up the boost. It treated me very well too.
Try to look in the yards around here and you don't have much luck finding TD VW's anymore. However, the prices of the TDI's are starting to come down. Every now and then I see a P-car, a renault and an IDI NA diesel...but most the motors, pumps etc. are all gone now.
Can't say as to whether I agree with your philo on TDI's in the lighter, more agile vw's. With the right suspension and drivetrain setup, and smart driving I believe supplemental power and a good foot will put all that either engine has to offer to the ground in a very good manner. To each his own though. My plan is to build the motor, rock solid, powerful and reliable. Key factory elements mixed with the right about of performance with an old school twist.
As for this project specifically, and IDI's. Man, we have learned alot of valuable information. Though sometimes the poll of knowledge seems a little "closed" when it comes to certain things, ideas, etc. most of us here are always open to share our ideas, thoughts and experiements. Just look at how much Jake has contributed and continues too. I remember when there was just a few of us...or rather, a few of us that we knew of on the internet here and it just grew from there.
I just bought this 79 rabbit just to enjoy "part of" the thrill and simplicity of the motor again and plan to keep it relatively stock...less power but 48mpg, I won't complain there. Your right, there was no similar sound to the IDI TD at high boost. I remember sitting there listing to mine idle and just hearing the turbo purr through the exhaust...very fun. The drive...amazing.
Its also great to see you took all the precautions, etc. to prep for this...though main studs might be a good idea. Though, might be beyond that since it would involve a teardown and line boring of the block to make sure that it is properly aligned when the studs are torqued but maybe things will be fine. There are plenty of TDI's (which run the same mains a rods...wow, 20 years...) running fine with factory bolts (minus the head bolts)
What'll be more interesting is how it holds the power to 7k, what kind of power it makes and how reliable that power/motor combination is. Sounds bulletproof to me and I'm sure it'll prove it on paper! As always...have fun!
Joe