- Is viable to add a
turbo to a blower engine or add a blower to a turbo engine.
- Using MAP or MAF
sensors to meter fuel flow simplifies the setup.
- Blower provides low
down boost and gradually cuts to the turbo for high boost.
The Lancia Delta S4 was famous for using a turbo
and blower in tandem. The idea of using a turbo and a blower together is not all
that complex and is definitely a doable mod. The theory is not difficult to get
around, but the practical considerations can be a nightmare if you don’t have a
suitable vehicle to begin with. Obviously, its advantageous to start with a car
that already has a turbo or a blower already installed. Space inside the engine
bay is also am obvious consideration. Lastly, your EMU must have the
sophistication to control both superchargers.
Lancia started with base engine which was already Roots blown. The Roots charger
already provided the low down boost so lancia set about implementing a turbo
setup to give the required top end boost. Lancias aim was to have good boost and throttle response at all points on the
powerband. For lancia in the 1980s, linking both technologies into a working package was
quite a feat. The complex intake system was complicated enough without even
looking at the rest of the system.
The air flows from a top mounted air filter, down through the turbo compressor
and on through the first air-to-air intercooler. From there the air takes one of
two roots or both routes.
Before the turbo makes boost, the air goes into the second intercooler and on
into the inlet manifold. As the rpms increase, the turbo begins to produce
usable boost and a bypass valve begins to open, bypassing some air past the
blower. As turbo boost increases to continues to bypass the blower until it has
completely bypassed the blower.
The Nissan March 3HB Super Turbo is an example of a production car with a blower
for low down response and a turbo for high end performance.