automationgame.com

when will there be a twin turbo setup for the inline 6 b/c i want to make the RB26DETT Engine

I'm also waiting for that. A quick search around the forum(even for that specific engine) would result in you finding a topic where they confirm this.
Turbo's need a revamp though, calculations are off, and just like I6 TT engines, also Superchargers will be introduced. Not until we see the main tycoon part done though...

oh nice so we have to see the campaign part first before any more content is put in the game

No, not "any more content". That particular content.

There were 8 new bodies released today. Within a month or so we should see V6 engines. But yes, there are some things that we will not see until the tycoon mode is out.

oh ok cool i cant wait to see the v6 engines i can actully look forward to making the VR38DETT engine to hold me over till the Twin Turbo setups for the inline 6 come out

I an AUtomation video from 2012 (playing with an v16 engine without the engine body), says that all engine calculations are finished, and only needs to make the 3d art engine.

All NA engine calculations indeed are finished, this is not the case for the complex FI stuff though.

Would you consider setting up an experimental build on steam (e.g. an opt-in beta) that gives access to everything that's defined, wether there is art or not?

Most likely not. There possibly will be an open beta before the official release, but not during the whole process, it'll be near the end if it does happen.