What exactly does this gizmo do? I know it may sound like a dumb question but just wondering what purpose it serves...thanks!

 

it releases the built up boost from the turbo so that it doesn't create too much. i have an 01 and i actually put a stud in the actuator for it so that mine no longer works. i am pushing 30-35 psi now!big difference when i was used to 15-20psi.

 

When pressure in the intake exceeds the spring pressure in the wastgate, the eastgate opens a passage in the exhaust portion of the turbo. Exhuast gasses then bypass the turbine wheel in the exhaust. Since there isvery littleexhaust flow across the turbine, the compressor slows down which in turn lowers the intake pressure.

 

5.9L DIESEL





Exhaust gas pressure and energy drive the turbine, which in turn drives a centrifugal compressor that compresses the inlet air, and forces the air into the engine through the charge air cooler and plumbing. Since heat is a by-product of this compression, the air must pass through a charge air cooler to cool the incoming air and maintain power and efficiency.Increasing air flow to the engine provides:[/b]
[*]Improved engine performance[*]Lower exhaust smoke density[*]Improved operating economy[*]Altitude compensation[*]Noise reduction. [/ul]
The turbocharger features a wastegate , which regulates intake manifold air pressure and prevents over boosting at high engine speeds and loads. When the wastegate valve is closed, all of the exhaust gases flow through the turbine wheel. As the boost pressure (compressor outlet ) increases, the boost pressure is fed to the wastegate actuator via a wastegate signal line. When sufficient boost pressure is achieved, the boost pressure applied to the wastegate diaphragm overcomes spring pressure and moves an actuator rod to open an exhaust bypass valve. When exhaust gas is diverted from the turbine wheel, turbine shaft speed is limited which reduces compressor wheel speed, thereby limiting boost pressure.
The turbocharger wastegate system incorporates, an Electronically Controlled Wastegate Command Valve, to control boost pressure. The command valve is located on the turbocharger compressor housing.
When the command valve is not actuated (no current supplied to the valve), a passage in the valve allows the wastegate signal line to be supplied with boost pressure. This allows boost pressure to be mechanically regulated by the wastegate as in a conventional wastegated system.
When the engine control module (ECM) provides a pulse width modulated (PWM) signal to the command valve, boost pressure is bypassed away from the wastegate signal line through a drilling in the turbocharger compressor housing. The internal drilling bleeds boost pressure back to the turbocharger compressor inlet (low pressure). Actuating the command valve, (bypassing the boost pressure signal to the wastegate) allows the engine to operate at a higher boost than would be achieved if the wastegate were allowed to operate normally.
Actuating the command valve does not increase boost pressure if the boost pressure is below the wastegate actuator setting. With the command valve actuated, maximum boost pressure at a given operating condition will vary based on ambient atmospheric pressure and temperature.

 

It's not a dumb question. If you don't know, you don't know. That's why were here, .

 

Quoting my math teacher in high school: "There are no dumb questions because what comes easier to some, is very hard for others..."

 

Hey viper I was wondering what ou mean by "I put a stud in the acuator" because I want to do something to my truck to build some more boost without spending a bunch of money.

 

mine does NOT have a waste gate

 

i actually took a small copper stud and inserted it in the line that goes to the diaphragm. with the stud there not enough pressure can get to the diaphragm to actuate the wastegate. works well. gained atleast 10 psi! just be careful!

 

Wouldn't you gain more boost with a larger wastegate? I don't know if cummins is the same kinda set up as a straight four turboed, but when i was racing straight 4's we'd swap in a larger wastegate to acheive less turbo lag and improve boost. Is in not the same in a cummins???