compounding is complicated with the wastegating and intake piping as there are a few different ways to go about it but if done correctly it can be great. especially if you choose a secondary turbo which is most efficient in the pressure ratio at which it will be operating on boost.
the most common way is to have all the cylinders feed into the primary (smaller) turbo's turbine, as this brings it onto boost the fastest.
Then when the small turbo is on boost the wastegate controlling the flow to the primary turbo opens, both the outlet of the primary turbo and the primary turbo wastegate combine back together to spool the secondary turbo.
also the secondary turbo compressor outlet blows air back into the primary turbo. this is beacuse the small turbo will flow more air at higher pressures, so becomes less of a restriction this way.
there are other ways of doing it but are more complex.
some have shut off valves in the exhaust to divert the exhaust to the small or large turbo which I guess is more of a sequential turbo system
some have one way valves between the secondary turbo outlet and the throttle body, this is so the primary turbo cant blow air backwards though the secondary turbo until the secondary turbo comes onto boost. this method removed any restriction which could be posed by the smaller primary compressor.
the diesel crowd use compounding heaps thats how they get 100odd PSI of boost comfortably. however they do chew out thrusts on turbos faster than tyres.
the most common way is to have all the cylinders feed into the primary (smaller) turbo's turbine, as this brings it onto boost the fastest.
Then when the small turbo is on boost the wastegate controlling the flow to the primary turbo opens, both the outlet of the primary turbo and the primary turbo wastegate combine back together to spool the secondary turbo.
also the secondary turbo compressor outlet blows air back into the primary turbo. this is beacuse the small turbo will flow more air at higher pressures, so becomes less of a restriction this way.
there are other ways of doing it but are more complex.
some have shut off valves in the exhaust to divert the exhaust to the small or large turbo which I guess is more of a sequential turbo system
some have one way valves between the secondary turbo outlet and the throttle body, this is so the primary turbo cant blow air backwards though the secondary turbo until the secondary turbo comes onto boost. this method removed any restriction which could be posed by the smaller primary compressor.
the diesel crowd use compounding heaps thats how they get 100odd PSI of boost comfortably. however they do chew out thrusts on turbos faster than tyres.
