Need info on the stock boost control valve

[elec87]

Hey guys I need some input on the stock boost control valve from the sy/ty.
Is this unit operated strickly on engine load/vaccum/boost? I know there is a solenoid or electrical vaccum switch that is inline with the unit what does it do and how is it controlled? Is the unit a simple on of 12 circuit or do they use a pwm control.
Thanks again

 

[dgoodhue]

Re: Need info on the stock boost control valve

Is this unit operated strickly on engine load/vaccum/boost?

The actuator is stricky operated on vacuum/boost coneection. On SyTy they open around 8-9psi.

I know there is a solenoid or electrical vaccum switch that is inline with the unit what does it do and how is it controlled? Is the unit a simple on of 12 circuit or do they use a pwm control.

PWM. It bleeds off pressure in the vacuum/boost line that goes to actuator, so the wastegate stay open longer. This allow more than the 8-9 psi boost that the actuator would open at.

 

[elec87]

Re: Need info on the stock boost control valve

Can anyone fill me in on the pwm frequency and pulse width signal the stock ecm gives out?

Thanks for the help and great input.

 

[dgoodhue]

Re: Need info on the stock boost control valve

Can anyone fill me in on the pwm frequency and pulse width signal the stock ecm gives out?

The ECM changes the PWM to control boost using the MAP sensor as feedback. It uses the Map Sensor signal, an error band (when it doesn't correct), and it uses a formula when boost doesn't fall into the desire parameter to control the boost. It change the PWM to change accordingly.

 

[elec87]

Re: Need info on the stock boost control valve

So there is not a set pwm frequency band or signal voltage range this unit operates in?
Thanks again.
Elec

 

[dgoodhue]

Re: Need info on the stock boost control valve

You could set a fixed PWM and adjust the boost via wastegate arm. This basically how some of the archaic boost control was done (GN). If using the stock turbo it will mostly likely overboost. You can also ditch the soleniod all together and just an electronic or maual boost controller (bleed off valve).