yes of curse i have my AFR innovate mtx installed

well look what STU motorsport devlopement says:
The most common thing I find
is that people have just tuned
their cars badly. On Bosch K I
see too much fuel pressure
caused via the shims, and on
KE I find people have gone
bananas on the electro
hydraulic fuel pressure actuator
to get more fuel for on-boost.
This is a bad way to tune and
the system will need a pro to
put it right again safely

What effectively happens when the
engine is running is this:
The fuel pressure is set in
this example, to 3.5 bar at
atmosphere. That’s with the signal
pipe disconnected. When we
connect the pipe, it acts on a
diaphragm and spring and affects
the fuel pressure with a ratio of 1:1.
This means that for every 1 psi of
difference the plenum has to
atmosphere, the fuel pressure will
be adjusted accordingly by 1 psi.
For example, if we have 1 bar of
pressure at the pipe (1 bar of turbo
boost), we will run our 3.5 bar plus 1
bar of additional pressure.
This has the effect of ensuring
the fuel pressure at the nozzle is
always exactly 3.5 bar above
whatever pressure is measured
within the inlet tract, so the fuel
fl ow is always constant and of a
known entity, unlike the fl ow we
had through the straw once we
equalised the pressure. Just think
what would have happened if we had applied 8 psi to the other end
of your straw... oops.
So, in a nutshell, we need to keep
the fuel pressure a set amount
above whatever pressure is seen in
the plenum at the injector pintle. If
we have 1-2 bar of vacuum in the
plenum, our regulator works the
other way and drops the pressure a
bar, too

this about the vacum PIPE Fuel
pressure
regulator:
Lean
conditions are not exclusively
created by the introduction of
additional oxygen, sometimes
they can be caused by a
reduction in fuel. When the
vehicle is mapped, a base fuel
pressure will be set on the fuel
pressure regulator. The small
nipple on the top of the regulator
is connected to the inlet manifold
and receives a pressure signal.
This allows the regulator to
increase the fuel pressure at
the same rate as boost pressure
enters the inlet manifold on
a turbocharged car and will
increase
in
approx half a bar
under acceleration
on an N/A car. If
this pressure
reference pipe
becomes
damaged or
detached
the fuel
pressure
will stay
static and
not rise when
accelerating,
or on turbo
engines when
boost pressure
enters the inlet
manifold. This will also result in a
dangerously lean condition