how much boost can the stock bottom end handle on a b16a? its jdm from an sir. im only at about 4psi right now and wanna buy a new wastegate spring. I was thinkin about going with a small blue(8.7psi) but i dont want to overboost it. its getting a tune right after i install everything - obd1 conversion, 3" exhaust, bigger injectos and the spring. it has 320s in there right now going with 550s. was also considering the small green spring(7.25psi).

Im selling the 320 rcs, obd0 dizzy, fmu and ecu if anyone is interested.

 

This has been covered many times...it's not the amount of boost you run but rather the amount of power you are making. Power kills motors not boost. But since you have a b16 that is stock I would say not to exceed the 300whp mark to be on the safe side with a good tune. Some people push their stock b's to 350+ but it's not really recommended for daily driving.