you could hook it up to a tire pump and see when it opens the flapper all the way, not very accucurate though.

 

it pulls pretty good, but i cant really get on it because i dont want chunks of motor laying on the road

 

ha, i was running with no wastegate (just block off plate) also a few weeks ago, i would hold it at 10-12 and it felt fast as ----, but you couldn't rape it, you had to ease it up there then feather the pedal to keep it there, now i have my wg on, but only have a 6 lb spring and it's a hell of a lot better simply b/c of that fact that you can bang it throught the gears instead of ----- footin up to 12, damn i need a boost controller to raise that ----