Heres a nice cutaway image of the S. Explains a little bit : http://www.stealth316.com/images/greddysopensm.jpg and the full website explaing a bit more: http://www.stealth316.com/2-greddy-bov-anatomy.htm And an install guide - although not for a starlet but has some pointers: http://herpetology.com/dsm/bov.html