I have read the article by Keith (http://forum.miata.net/vb/showthread.php?t=363284) that states the NA booster is 4.74 assist and the NB sport is 6.4 assist. It does not make sense because the size and diameter are both the same. In order to increase boost assist you must increase diaphragm size. Look at the non sport NB option they run a double diaphragm in order to get more assist. That's why it's so much thicker.

One of my friends who is struggling with VR8 brakes made the swap and said the pedal sensitivity was less with the sport booster than the NA booster. I expected it to be worse.

What kinda black magic is happening inside of those things?

Thoughts? Comments?