Air Injectors?

MORF114

Active Member
As title says just wondering what they are used for i know/think they are for boost control but whats the real use of them and how they work?

How come no one uses them ive seen a few escort cossies and rally cars with them but no R 's.
 

MarkTurbo

Well-Known Member
MORF114 said:
How come no one uses them ive seen a few escort cossies and rally cars with them but no R 's.
;-)



You'd need an aftermarket ecu to run air injectors on an R, they do control the boost quite well but the downside of them is if they stop working your engine will run as much boost as the turbo can make :lol:

Heres a clearer picture of them:



How do they work?
The air injectors have an input to the top of them from the turbocharger and an output on the bottom to the wastegate. The injectors are wired to the ecu so they can be controlled.

The ecu air injector map is mapped against boost, rpm and air temperature. The injectors initially stay closed, keeping the wastegate closed too, encouraging the turbo to spin to speed as fast as possible. When the desired turbocharger pressure is aquired during mapping, the injectors are pulsed so that they open at that point, allowing air to flow to the wastegate. This of course opens the gate, bypassing some exhaust gas from the turbine wheel, slowing the compressor and leveling or dropping the boost pressure depending entirely of course on how much air we allow through. The beauty of this system is we can use a relatively weak actuator to achieve very large boost levels and we can accurately program boost curves into the system.

Any downsides?
Yes, if the injectors fail, due to the “Bleed On” configuration, the turbo will run whatever boost it can until something either stops it or something fails due to the fact we have blocked the pipe to the actuator.

In other words an electronic boost controller is better ;-)
 
Also air injectors are set up using duty rather than just selecting a certain boost level (like many electronic boost controllers) which means they are more difficult to setup and alter once set up.
 
P

pulsarboby

Guest
all toooo much for my miniscule brain:doh:

didnt know you were so clever markie!
 
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