Hi all, first post. 10 year rider, current SV owner, Eye'n a busa.
As with most any engine mod, used sparingly the additional wear on the motor is negligable (sp?). But +40hp is about as far as I'd push a stock engine on juice. Advertisements say 40% can be done on a stock motor, but if I'm going to loose on a Nitrous-Fed, 190hp Busa, that extra 20HP probably isn't going to help.
If you're looking to get that extra power, I'd suggest looking into a progressive controller kit. They use two sets of jets & and RPM controller. The first 30HP comes on at about 6000 rpm, the second jets, adding an additional 30 HP (for 40% total gain) come on at about 10,000. This is seriously pushing it, and recommended for top gear only. :0
-Noltez
Silver '02 SVS; damn near stock.
PS: Dry nitrous has no effect on the intake manifold, other than chilling it slightly.