hi folks
i have a k03 hybrid with RS6-sized wheels in machined housings and 1.0 bar custom actuator. now im drive with 1.4 bar (or 20 psi) and all seems ok. but it can produce about 1.8 bar (26 psi) boost. car pushed really hard with good IAT, knocks and AFR (btw turbine noise more quieter at this boost level)

so now i thinking to buy 3 bar map sensor, make an 5120 hack and run overboost at 3 gear only because it makes no sense at 1 and 2 gear in FWD car and to prevent overloading turbo at 4 and 5. so it will be running only ~5-10 secs with overboost. so the question is how bad it is for turbocharger? and yes nobody know about quality of this hybrid turbo so lets imagine that it is K03

any suggestions? car is 1.8t w stock ex mani; stock catback and 3" downpipe another HW is ok to handle it

how i can calculate efficiency wo compressor map? maybe comparing air consumption on different pressures?
yep there is a good fmic which gives +10..+20c higher IAT than ambient temp

dunno
has no sensor to measure it, only egt model that shows something like ~800 at wot

btw i forget that im running 0.8 bar actuator spring now that can provide only 1.4 bar. to achieve 1.8 i should replace it with 1.0 bar which are very unconfortable at mid-range light loads. so... leaving this

Don't just rely on just monitoring the IAT. Place a temperature sensor (just stick it under the hose clamp) after the compressor but before the intercooler. As soon as the temperature of the air leaving the compressor is not linear anymore with increasing boost, but rather exponential, you are starting to push the compressor side too much.
Also, measuring back pressure in the turbine housing is a good idea alongside the EGT.

so i made some searching and seems that it is 2277 comp. wheel in k04-022 machined housing. turbine wheel also different
i have no experience in it but believe that hotside has a high backpressure because it can produce 1.4 bar only with 0.8 bar actuator spring  (with 95% WGDC at top-end)
no idea why they used this pretty compressor with useless hotside. it produces ~220 g/s on 1.4 bar.. same level as k04-023 with 1.2 bar and stock actuator... so im leaving this idea, thanks all :