Spoke to a top bloke from BogWarner Turbo Systems (who are the section that deal with all KKK Turbochargers now) .
This guy used to work with the K-16 turbos a lot and, even after the cars being out of production for the last few years, knew all about the way it worked for the C20LET. He had "fond" memories of stripping down numerous KKK-K16 turbos at Vauxhall for them as well
What he is saying is that the maximum load for this turo unit is 2.5 bar Absolute which equates to 1.5 bar normal
This means that the Phase kits running 22psi overboost and then dropping to 17psi are just at the maximum. The turbo should take it but it obviously wont last as long as if it were running 10psi.
The main point is that running 22psi thru the KKK-K16 is NOT out-with its limits but is just touching the maximum.
He did recommend not running 22psi at 5000+RPM of course
I was also looking through Garett flowcharts, for 'equivalent' models to the KKK-16
Say the T3 with 40mm and the T25 with 60mm dia
Their top is just about there as well.
Just as we suspected, 22psi is really pushing it.
Remember that these figures are for sea-level. If you're up in the highlands, the turbo works harder, and it may go belly-up if you try these antics.
Personally, I wouldn't let my turbo do more than 20psi. Call me whatever you like.
On a high-spec hybrid through....
Aye 22psi is the maximum but he did mention that this would be the maximum constant boost he would recommend so running 17psi should be ok.
I meant to say that this is coming from his memory and his experience but he would have to look it up to get exact values. Going by what he said he used to do, I dont think there will be much diff TBH
Also, because of the design of turbo he did say the standard actuator spring will give up due to the heat etc. Dont matter really as the standard actuator will be hard pushed to get you to 22 psi unless its brand new.
Turbos DO wear out anyways. The K-16 has a life expectancy of about 80,000 miles so no-one should be shocked if it does give up eventually.
Just replace it with a good hybrid K-16 (or standard K-26 ?? ) with a reliable 360 degree thrust bearing and cut back blades and your upto about 25-28psi (Turbo Technics hybrid)