boost Problem ST215

[AW11 Turbo]

hi all!

i've a 3SGTE rev4 out of an Caldina ST215 running in my MR2 MK1.
(rebuilt engine, wiseco Pistons, 3" Exhaust, Haltech E8)

the last 2 years i drove with ~0,7bar (~10psi) - no Problem at all

last Friday my Haltech Tuner activatet the Haltech Boost Controll Solenoid.
(the port on the wastegate actuator which would normaly go to the vsv is blocked off, the line from the Turbo to the actuator is spliced and fitted both sides to the boost controll solenoid, the third port on the solenoid goes to free air)

with the boost controll solenoid activatet the boost goes on the dyno up to ~1,2bar (17psi) @4500rpm, then it drops to ~0,8bar (~11,5psi) and at ~6000rpm it rises slightly to ~0,9bar (~13psi)

on the road i have spikes of ~1,4bar (20psi) and then it drops to ~0,9bar (~13psi)

a can also hear a rattle noise wenn boost drops...

would a other wastegate actuator with a harder spring help here?
or what do you guys think is the problem???


this is the dyno sheet:

[strx7]

what model Haltech have you got on it, I'm pretty sure that the boost control spart of the software is set up on bar graphs just like the rest of the programming and I would say that the graphs are set to run higher boost then drop it off a bit then up it again, cant really see any other way of how it is possible, and I assume its got a std turbo and wastegate? I'd say you are also having boost spikes from the wastegate not being big enough

[AW11 Turbo]

its a Haltech E8
the bar graphs for the boost controll solenoid are set to 100% duty cycle for every rpm and load
and yes its the stock st215 Turbo and wastegate!
my idea is that the stock wastegate actuator opens it self because of the exhaust gas pressure...
do you think it would help mounting another wastegate actuator with a harder spring (the original opens at 0,7bar)

[Quirky]

try connecting the wastegate directly to the inlet manifold, and disable the boost control.
Also its a good idea to program a boost cut.