Tommy Cookers wrote:your turbo-compound ??
Please elaborate !
Its a turbo compound system like the diesel tractor puller's run, but on gasoline.
My Compound Turbo System:
4G63 DSM 2.0L inline four cylinder engine
Rear-Mount BW S400SX4-75x100mm ETT, Atmospheric Primary Turbo with a 1.32 A/R Turbine T6 Flange 60mm waste-gate dump to atm, rated at 1050HP.
Engine-mount or Second stage EVO III 16G with a 28mm internal waste gate rated at 450HP.
DN Performance exhaust manifold with two Tial 44mm gates, FP O2 housing
TurboWerks Exa-Pump Electric Oil Scavenge Pump for Primary turbo return.
God-Speed FMIC
How the turbo compounding works is the small secondary turbo will spool first at its low flow lower rpm. This lets me run a tighter converter. When the small turbo reaches its max flow around 41lbs/min all that exhaust flow is sent to the larger turbo(about the same exhaust flow as a 350 CI N/A engine at 4500rpm). Around 35lbs/min the larger turbo will start to spool and then comes on line. Once the flow is over 41lbs/min the 28mm wastegate is choke and the first 44mm gate will open. Then once the engine starts flowing over 60lbs/min the second 44mm gate starts to open. Now the small turbo has still only 41lbs/min of exhaust going through its turbine and by-passing all the rest around it(BP drops a ton). The larger BW turbo has a 60mm wastegate and dumps to atm. to control the 45+ lbs.of boost.
Advantages:
No turbo lag
Massive amounts of torque
Very low engine back pressure