Correcting previously stated ways to calculate and tune compound turbo setups

My older videos have some misleading information that I learned from other more well known diesel shops. This video corrects the mathematics so it works in either direction and the end results are accurate and actually useful. Leaving both videos up as all of this is a learning experience and this is a great example of such.

[@TurbineResearch]

“Increasing the head pressure” on the small charger was a 💡 for me

[@savagefabrication795]

It makes cylinder heads make a lot more sense also :)

[@nemanja162]

100% correct and its how i mapped my compound setup. People dont seem to be able to separate boost pressure numbers from their PR at sea level for the manifold mounted turbo.

[@savagefabrication795]

I was guilty of that for a long time lol.

[@CompoundKodiak4x4]

Im putting together a compound system om my Kodiak. Can you go into the possible benefits of intercooling between the atmo and manifold turbo. Seem like there would possibly a bunch of efficiency to gain by doing so. Maybe do a hypothetical with and without interstage intercooling.

[@bcbloc02]

You don’t have to compromise if you run your engine at a constant load and speed. 😎

[@savagefabrication795]

Haha agreed 😎

[@elroyelblander6277]

👍👍👍 good stuff,once again feller.. even tho most of it went over my head with all that algebraic business 😂😂,but anyway 👍👊

[@savagefabrication795]

Just practice it on paper and it gets easier haha

[@jean786]

How much % are the difference between the small turbo and big turbo?

[@savagefabrication795]

@@jean786 I don’t think percentages are probably a good way to do it due to scaling. The main goal is to (and it kinda goes against one another) but the atmo needs to be as large as possible on the turbine side to set the system up so the pressure drop through the manifold turbo turbine housing is as great as possible. This is known as the expansion ratio and is important for both mass flow rate aswell as work done to the turbine wheel. But as small as is possible so that the system is responsive and hits target pr as quickly as is realistic then maintains it through the rpm band. This is also mani charger dependent but as of late either through housing size or waste gating the atmo charger and adjusting it’s pr to change the speed of the manifold charger to a better location has been yielding extremely awesome results.