What the maximum boost you can get out of a 14B. 18-20psi??

I've been tuning for knock with a logger.

I guess I'll rephrase my question, I was looking for the physical output limit of the turbo-if there is one. I was curious what the maximum boost a 14B can put out and still be efficient. There's got to be a limit before being required to step up to the next size turbo.

IMO it depends who you talk to. The general consensus is about 17-18. After that efficiency drops off and it creates too much heat to benefit the engine. You can run it at higher pressure levels but it also decreases expected life span.

I found a loss of performance above ~18psi.

^^^^bingo.

Thanks guys, that's what I was looking for. I figured at some point, you'd reach a performance wall and it would be time to upgrade.

I wouldn't recomend anything over 18psi assuming you keep the knock count in check, unless you want to change parts frequently.

The 14b has been tested to 405cfm @ 15psi with a 6cm2 housing and to 465cfm @ 15psi with a 8cm2 housing. The 16g is good for 505cfm and the 20g is good for 650cfm at the same 15psi.

I've seen a list that says the 14b is capable of 275-300HP at 21psi, while a small 16g is capable of 345-365hp at 22psi on vfaq.com.

The most I normally ran was 18-19 on the street with my 14b. I did run 24psi at the track and seen someone else run 25psi with 12second passes, but life expectancy of the engine and turbo are shortened greatly. For reference My quarter mile times reflect a 300-310 calculated horsepower at 24psi which means I didn't gain anything over the 21psi listed above. Plus I was using 112octane leaded race gas.