Also the used custom turbochargers are much more expensive than buying off the shelf and any change to the combustion will be followed by a new to develop turbocharger.
Illien also slams the 3 engine rule. It it is working the other way around, because there are only 3 chances to put in new developments, every development is tested and checked for multiple times on the test bench. And again a high-tech testbench to simulate a real f1car in motion is so more expensive, that is another thing a small engine builder cannot afford.[/s]
Thanks dude, so much better than mine.
![Razz :P](./images/smilies/icon_razz.gif)