Raising the Boost

Like i said there are multiple ways of raising the boost level:
- Using a Bleed Valve
- Electronic Boost Controller
- By Actuator
- By Actuator DIY

The bleed valve, the first way, least attractive way, it works by adding a small bleedvalve to the hose controlling the actuator.
With this bleedvalve we can "bleed" away some of the boost the actuator sees, so you are tricking the actuator into thinking the boost is lower so it stays closed longer, thus raising the boost.

The reason why this is a bad way is because basically you have an open air leak in your system, it's leaking away air, losing boost pressure, and it really has to leak away quite some boost to be able to fool the Actuator and some modern ECU's won't even be able to cope with this.
This device can only be used to RAISE the boost, not LOWER it.

The advantage of this way is that it is a cheap way of doing it.
(But not THE cheapest, read on :) )

This sounds more like it, Electronic Boost Control, from the inside of your car! How about that!

Sounds great, and it is! Here's how it works:
An electronic boost controller usually works using a solenoid (electronically controlled) valve.  A solenoid valve would have 3 ports (sometimes 1 is hidden inside the housing), and 1 port goes to the wastegate, the other port is hooked up to the intake, and the last port is left open to the atmosphere.  The solenoid can switch between connecting the wastegate port to the intake port, or connecting the wastegate port to the atmosphere port.

Suppose you want to run 14PSI of boost, then a electronic boost controller should do this -- when the boost reaches 14.1PSI, the solenoid will connect the wastegate to the intake, causing the wastegate to open (since 14PSI is higher than the 7PSI required to open the wastegate)... the turbo will start slowing down, when it drops to 13.9PSI, the boost controller will then switch the solenoid and connect the wastegate to the atmosphere.  This causes the wastegate to close since the atmosphere is 0PSI lower than the 7PSI needed to open the wastegate, and the turbo will start speeding up again.  This happens rapidly and keeps boost regulated nicely at 14PSI.

Most boost controllers accomplish this by figuring out what percentage (or ratio) of the time the solenoid would connect the wastegate to the atmosphere vs. connecting the wastegate to the intake.  This ratio is often known as the DUTY CYCLE, the duty cycle is directly related to the boost level.

Now this is the main function of the boost controller, but there is another benefit to running a electronic boost controller, and that is it will allow the turbos to spool up a little faster.  How does it do this?  Well, a wastegate might be designed to open at 7PSI, but it usually cracks open a little even before the pressure hits 7PSI.  This will slow down spoolup of the turbo, causing it to hit 7PSI a little later.  A good electronic boost controller would keep the wastegate shut for as long as possible, by using the solenoid to connect the wastegate to the atmosphere (0PSI) till the turbo gets really close to hitting the boost you want, only then it will start switching the solenoid back and forth according to the duty cycle.  To determine how long to keep the wastegate shut, most electronic boost controllers use a number known as GAIN.  If the gain is set too high, the boost could spike (the wastegate is held closed a little too long causing overboost), but if the gain is set too low, the spoolup is not as optimal as it could be.  Getting the correct gain setting will give the optimal spoolup of your turbos.

This is a great solution in controlling the boost, and you can even control it from the inside of your car, the downside to this is that it's the most expensive way of controlling the boost and the installation takes longer.

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