Small update... I really haven’t got the time lately to do anything, but last weekend i had some spare time.
I took the car inside and mounted engine+trans, adjusted all angles and made me a gearbox bracket. It still needs to be reinforced and fully welded.
Then, thanks to the internet, things got a little out of hands again. I stumbled upon a guy/company who had done a E9x 335d triple turbo with good success so far. So i did a lot of calculations and thinking, and decided to go for it.
The third turbo will be compounded with the oem big turbo. Can you spot it in the picture?
The third turbo will need all kinds of wastegating and a lot of precise control to make everything work together. I will probably build a dedicated controller for proper boost control.
Some progress on this one...
Piping basically done for the turbos. Don't mind the welds, that's the result of a left-handed beginner equipped only with a stick-welder for stainless.
It's a ~70-75lbs capable turbo, i'm intending to run it at 2-3:1 pressure ratio and hopefully be able to keep the K26 closer to 2:1 pressure ratio to achieve what i want at this stage. I would've fitted a bigger one, but there just isn't enough space, and after doing a ot of flow calculations this turbo actually seems better suited for my goals (at least on paper). My power goal is pretty lame, >600hp is enough. Won't be achieving that though without some upgrades on the fuel system, which will take place next winter.
There's going to be a lot of things to measure. Will have my own controller dealing with all of it + WMI. PCB design is ready, but no hurry in manufacturing as there can still be some changes to the design.
2x temperature sensors for boost temp in different stages
2x Pressure sensors for boost pressure in different stages
2x Exhaust pressure sensors for EGP in manifold/mid-pipe
1x EGT in exhaust manifold
2x Wastegate position sensors
2x N75/MAC solenoids to control wastegates (PWM)
1x PWM output for WMI
2x extra digital outputs (for control of OEM turbos if i decide to go that way)