Well, let's think through this logically.
First off, if IATs are truly higher, the problem is obvious: an intake manifold at the same pressure with higher temperature contains fewer molecules of air to burn. In this case, if the turbo is truly "just blowing hot air," this is usually because the compressor itself has been run off the end of its efficiency map. This is usually due to poor compressor blade design (there is a LOT of fluid dynamics-fu that goes into making a compressor blade that runs efficiently), incorrect A/R, or poor backspacing letting compressed air revert back out of the turbo.
This is what I was looking for
My mind was only on IAT vs pressure, also looking at MAF flow. In most case pressure and IAT goes up, Mass air flow stay same.
Yes I notice that Backpressure is one more downside off chinese turbo, I didn't mesaure it, but I can guess by KR that there is a lot backpressure
Found the answer:
Not sure what you're expecting.
I didn't expect anything, I don't have those turbos, I just compared logs I made on those cars.
It is funny(or maybe sad) that someone make a hybrid from stock K04 on milling for 50-100€ , than they car make less or same power than before
Well, first of all there are cheap ebay turbos then there are half decent chinese turbos.
The hybrids and factory OEM replacement "hybrids" usually fall in the lower category, in my opinion if you are buying a chinese turbo do not buy anything smaller than a t3 housing or bigger.
Now ofcourse, just remember what you are buying, they are with cast wheels 98% of the time , not as efficient turbine designs and so on, you will always have compromises vs a big brand name that spent millions of R&D on this stuff and dynamics etc.
IMO they certainly have their place , but some of the things you say are just not true anymore, they improved massively in the past 5 years or so.
One of the main chinese turbo users on youtube for example are Boostedboiz and they made ridicolous powers with them and they actually lasted a long time (just remember again they didnt buy the lowest of the lowest), mine is doing good too.
For balance again, that isnt the case anymore, as it has been proven recently with turbos such as maxspeedin that they have some vsr balance (mine does is too).
As for A/R its true most of the time they dont actually hit the A/R of the housings they say , just have to remember that , specially on the lower grade, also almost always need wastegate hole "expansion".
If you want to spend a tiny bit more more than these you can always get Holsets, Airwerks, or the 'new' GTW's from Garrett.
Big turbos are different story, my focus was on this small turbos, and the one they sell for "bolt on"
lol
Why lol?
