my buddy got a t3/t4 turbo. he's going to be running it on a b18b. with bigger injectors and a custom chip burnt, how many psi can be run safely on a stock internal motor? how many psi can the stock map sensor handle?

 

I believe the stock MAP sensor is good for around 11ish psi.

As far as how much whp the engine can handle, many people have gone well over 300whp on completely stock B18A/B18B engines. Just depends on the condition of the engine, the quality of tune, etc I guess.

 

In case you have not noticed this thread yet:

https://honda-tech.com/zerothread?id=1323059