I have both books, excellent. Each has its finer points. Hugh's book is far better for the actually turbocharger aspect. More diagrams, formulas and details, but its getting very outdated. The standard turbo today is a Garrett T series... turbos designed in the 60's modern GT turbos have sooo much more going technologically. Corkey's book gets into the finer points of building a great turbo setup. The section on intercoolers and airflow is especially good. Neither cover oiling very well unfortunately.