was looking aroung MKIV.com a couple of days ago...followed a link to powerhouseracing.com and saw they had a turbocharger for the IS...wrote them an email and this is what I got back this morning...
Sir, we do offer a custom built turbo system for the IS300. A basic system
that offers about 300 HP would cost $7500. The next step in performance
would be 400 RWHP at a cost of about $11000. There are no supercharger
kits available for the IS300 as of now. The turbo system replaces the
headers, intake, etc. We also offer a fuel system upgrade and ECU
modifications for the turbo system. Labor to install a system is about
$1500-2000. Thanks
Jarrett
http://www.powerhouseracing.com
too bad i don't got 11000 to throw into my car right now...400rwhp sounds pretty tempting