Wastegate

[eckman]

is there anythign I could do to the wastegate to give more performance on the stock turbro ? anything..... ? Can you adjust the stock wastegate ?

[Rokkit]

The TD04 is netorious for trailing off towards redline... what you could do is tighten up on the waste gate arm and reduce the amount of trail you have. That would boost your performance, however, you need to be careful doing it... too tight and she wont open...

Im thinking about tighting up on mine a little before my next tune so i can get tuned at the anti-trailing setting :D


Btw... Will is pulling 260 to the wheels out of the stock turbo...

I hope to be in the same boat in a few weeks

[eckman]

Any instructions, pictures, videos, tutorials on how to do this ?

[Defiantspaz]

Check out www.spomotorsports.com they have new wastegate actuators.

AVO Solid Response Boost Controller
Raises boost from stock 13.5 to 15 lbs and keeps the boost from falling off at higher RPMs. It is custom made for the WRX and isn't just a universal boost controller. This is a very reliable system and a lot of performance for the money. You will need a boost gauge in the car to initially adjust it.
Part# spobc
Price $269.00

This could be alot safe than messing with your stock unit.

[eckman]

That's awesome ! so....what do you adjust ? what's a "wastegate" ? How is losing boost at 5k related to the wastegate function ?

Thanks.

[Defiantspaz]

The stock boost controler on the wrx pulls away boost as the revs climb.

The solid boost controler has a threaded section for adjustment. The boost controler holds the wastgate shut longer holding more boost, longer.

Also another way to go is a dual boost controler from Turbo XS. I had a 2002 WRX and I used this controler on my car. Again you need a boost gauge to set the controler. It was useful because you can set your boost low for everyday driving and if the temptation sets in flip the switch and full boost is yours.

Dual Stage Boost Controller (BC-DSBC) US$249.00
The Dual Stage Boost Controller allows you to switch between two preset boost levels with the flip of a switch from inside the car. Got a high horsepower Front Wheel Drive turbocharged car that can't get off the line? Use the BC-DSBC to launch the car with low boost than switch to the second stage higher boost level for maximum top end power.

I think I can get a used one for you in good shape for around $100.
Let me know if you are interested.

[Defiantspaz]

The part of the turbo that looks like a fan is the turbine, the other part is the wastegate. If you look at the upper right side of the turbo is the wastegate actuator. That is the part that the solid resp. boost controler replaces. The turbo XS controler goes in the boost lines in between the boost ports on the compressor and the wastegate actuator.

[eckman]

Why would one choose the wastegate vs. the dual boost controller ? Can they work together? Can teh DBC effect the stock wastegate negatively ?

[Defiantspaz]

The wastegate itself will not be changed. The actuator that opens the gate is what is replaced by the AVO unit. The turbo XS DBC controls the stock actuator by holding it closed until the turbo make enough boost press. to open the ball and spring, thus activating the stock actuator to open the wastegate. You could do both but it would be a waste of money. The AVO unit is stealthy, but the TXS DBC has more flexibility and may be more useful when you install a bigger turbo and the AVO unit just may not fit it.
I would go with the TXS DBC because it will fit into your modification plans better than the AVO, unless you plan on running the stock turbo then it's a toss up.

[eckman]

I plan on keeping and utilizing my stock turbo as long as I can, safely. From my searchings, readings and learnings I don't believe I have ever read anything about wastegates and adjusting them. I like to be able to adjust what I can without upgrading a specific part. I like get the most out of my current investment before I change it. The main reason why I choose Cobb. Went with grounding it and hopefully soon going with the HyperVoltage system. I like the little stuff before spending money on a big item. That being said.

How would the DBC be a good item install with the stock turbo ?

[FlyinbySTi]

personally, I think the stock waste gate is pretty functional. Alot better then the stocker on the Typhoon. Just remember any time you are tightening the waste gate rod you are increasing boost. How efficient is the stock turbo at higher boost levels.

I would get the puck welded shut and just go external, with a boost controller. Then you'll have a nice even curve all the way to the top.

[Defiantspaz]

The DBC would not adjust the wastegate. The wastegate is basicaly a door. When the door is shut the turbo makes boost, as the door opens the turbo starts to lose boost. Instead of your hand opening and closing the door the wastegate actuator does it for you. It is the little brass looking thing on the turbo with the rod stuck out of one end and a vacuum hose on the other end.
This is the part that the DBC would control. When the DBC is set very low the ball and spring have very little tension so not a lot of boost is required to push it open and activate the wastegate actuator, which opens the wastegate and bleeds off the extra exhaust gas to maintain the desired boost level. With the DBC set high the ball and spring have a great deal of tension and require a lot of boost to push them open, that is how the DBC would control your stock wastegate and actuator assembly. I ran 11PSI low and 18PSI high on my 2002 WRX. As for welding the wastegate shut and getting an external wastegate, unless you plan on running a turbo without a wastegate internaly I would stay clear of this approach.

From APS:
The Standard TD04 turbocharger installed on the WRX is well matched to the required power output of the stock WRX. At 220 hp - 230 hp and around 13 psi of boost pressure, the TD04 is within its limits and with the potential to supply enough air to produce 280 hp.

Typical of any turbocharger, as boost pressure is increased past the point where peak air flow is produced (at around 19 psi of boost pressure), air flow, hence horsepower decreases.

[Defiantspaz]

If you have a boost gauge and some spare time I can hook one up for you so you can see how it works. I will be going to the drag day at Lebanon Valley Oct. 14th. If you are going I will bring it so you can try it out. The install is preaty simple just remove the vacuum hoses from the turo and put the DBC in between the compressor port and the actuator port. You adjust the boost with a small allen key.

From Turbo XS:

2002 Subaru WRX TurboXS boost controller Installation Instructions
1. Disabling the Factory Boost Controller.
Locate the vacuum hoses connected to the turbocharger. There is "T" with one line running to the Boost Control Solenoid (located under the pop off panel next to the airbox), one line running to the nipple on the compressor side of the turbo and one going to the wastegate actuator.
Disconnect the hose connected to the to wastegate actuator and the line connected to the compressor outlet nipple. These lines are now connected to the "T" and the factory boost control solenoid. These must be blocked off and secured.
Do not discard or use these hoses in the installation of the TurboXS Boost Controller. These hoses contain restrictors and must remain intact to restore your WRX to its original running condition.
2. Establishing a Boost Source for the TurboXS Boost Controller.

Connect a new boost hose running from the compressor nipple on the turbo to the brass nipple on the TurboXS Boost Controller (inlet).
3. Establishing a connection for the TurboXS Boost Controller to Control the Wastegate.

Connect a new boost hose running from the wastegate actuator on the turbo to the TurboXS boost controllers blue nipple (outlet).
4. Secure all hoses and caps with hose clamps or wire ties to ensure no hoses or caps come loose. A loose hose could result in excessive boost pressures and severe engine damage.

5. Securing the TurboXS Boost Controller.

Use the 2 screws on the boost controller to attach the provided bracket to the TurboXS boost controller.
Locate the brake proportioning valves next to the pop off cover on the passenger side of the engine compartment and secure the provided bracket to this square hole with an appropriate bolt and nut.
6. Adjusting the TurboXS Boost Controller.

1. Fine Adjustment or bleed screw (Blue).

Use the supplied 2mm allen key to increase the boost by turning the allen screw counter clockwise. One turn of the fine adjustment screw will result in approximately a 1 psi increase in boost pressure.
2. Coarse Adjustment or Ball and Spring (Brass).

Use the supplied 2mm allen key to increase the boost by turning the allen screw counter clockwise. Set your baseline by turning the coarse screw counter clockwise from flush until the ball no longer rattles in the boost controller when shaken. One turn of the coarse adjustment screw will result in approximately a 3 psi increase in boost pressure.
7. For more details on tuning your TurboXS Boost Controller, please refer to the instructions included with your boost controller.