Tim Wasmer

Guys,

I have Gready ProTech controler in my car. I have set the P1 and P2 modes. And that is all good BUT I have no idea what this thing is for.

Anyone have an explanation about what a Boost Controler does?

Thanks

Kevin

Basically it allows you to set the levels of boost pressure that you want to run. When you run EBC you run outside of the factory ECU's boost control. I'm not a fan of EBC's..

Aaron14

Boost controllers effect how much boost you utilize:


"Manual boost control

A manual boost controller is a simple mechanical and pneumatic control to allow some pressure from the wastegate actuator to escape or bleed out to the atmosphere or back into the intake system. This can be as simple as a T-fitting on the boost control line near the actuator with a small bleeder screw. The screw can be turned out to varying degrees to allow air to bleed out of the system, relieving pressure on the wastegate actuator, thus increasing boost levels. These devices are popular due to their negligible cost compared to other devices that may offer the same power increase.

Generally a manual boost controller will not be accessible from inside the car, though some are designed to be. An installation that allows access from inside the car (as opposed from inside the engine compartment) is more complex, as the tubing must be longer and a hole must be drilled. It is possible and beneficial to use two manual boost controllers at different settings with a solenoid to switch between them for two different boost pressure settings. Some factory turbocharged cars have a switch to regulate boost pressure, such as a setting designed for fuel economy and a setting for performance.

Manual boost controllers do not solve partial throttle/full boost, drivability, and response or lag issues. They can be used in conjunction with some electronic systems.
[edit]

Electronic boost control
A 3-port pneumatic solenoid. This solenoid allows interrupt or blocking of the boost pressure rather than just bleed type control.
Enlarge
A 3-port pneumatic solenoid. This solenoid allows interrupt or blocking of the boost pressure rather than just bleed type control.

Electronic boost control adds an air control solenoid and/or a stepper motor controlled by an electronic control unit. The same general principle of a manual controller is present, which is to control the air pressure presented to the wastegate actuator. Further control and intelligent algorithms can be introduced, refining and increasing control over actual boost pressure delivered to the engine.

At the component level, boost pressure can either be bled out of the control lines or blocked outright. Either can achieve the goal of reducing pressure pushing against the wastegate. In a bleed-type system air is allowed to pass out of the control lines, reducing the load on the wastegate actuator. On a blocking configuration, air traveling from the charge air supply to the wastegate actuator is blocked while simultaneously bleeding any pressure that has previously built up at the wastegate actuator." - Wiki

Tim Wasmer

Hummmmmm

So if I understand correctly there is other mechanical control of my wastegates ?

This was in my car when I got it. Just not sure WHY it would be in the car. I am going to look at my turbos to see wher they might have tapped in.

Kevin

Tim if your EBC is installed the factory N75 frequency valve is bypassed. Normally the stock Motronics would control the N75 to supply control pressure to the actuators mounted on your turbochargers..

Tim Wasmer

Dude.......ENGLISH please

Hope you know I am kidding you

Kevin

When your car left the factory. The method of boost control had your engine brain controlling it's own boost control valve=N75 frequency valve. The ECU will use the MAF in your engine to measure airflow and calculate the amount of boost that is allowed. When boost starts to exceed the values in the ECU mapping the ECU will energize the frequency valve. This N75 valve opens and allows intake manifold pressure to flow to the turbocharger actuators. The actuators fill with air and move a piston which is connected to the wastegate lever on the turbine housing. Once the wastegate lever arm is moved turbine exhaust pressure is bled off. The turbine wheel slows which is connected to the compressor wheel which generates less boost now.

Your Greddy removes the factory ECU and N75 valve out of the loop. It allows you to select the boost threshold parameters. The EBC now controls manifold pressure and allow pressure to be sent to the actuators to open the wastegates.

Red9

Kevin-- why are you not a fan. What is good about Extexrnal control? What is not (so)good?Equally the alternatives are? Why?How?

TB993tt

Motronic M5.2 is programmed by Porsche to give optimum output for the operating conditions by minutely controlling timing,fuelling and boost. You are removing one of these modes of control.
Done well external boost control can work but never as optimised as a Porsche/RS Tuning/Ruf/other reputable tuner programmed set up - fortunately it is difficult to blow your engine up on these modern engines since the Motronic still controls timing and fuelling - so wind in as much boost as you like, if the engine is not set up spot on for it you will lose timing and eventually spark and/or fuelling

Tim Wasmer

What happens if the device is "off". DOes it revert back to stock control?

Greg H.

It has been stated in the past here that Motronic control doe not actually measure boost. It regulates based on other parameters but doesn't know what boost is at any time.

Two questions: Isn't that the reason why some tuners like the EBC- because it is difficult to tune the engine closer to the limit using the other parameters.

Secondly, what is wrong with pulling timing, spark and fuel if the Motronic senses a problem.

I have a modified Motronic unit and am a believer in what Kevin and Toby have to say. On the other hand, my car has been on a Dyno right after an EBC, K24, larger fuel injectored car that showed 150 rwhp more than mine. It keeps me awake at night wondering if I'm leaving a lot on the table.

Greg H.

Tim Wasmer

Greg:

Isn't it a bit about "risk" as well?

Is one a more "safe" way of doing things vs. the other? i.e. damage to turbos etc....

Kevin

If the car isn't put on a dyno and tuned or tuned period for your engine, the risk greatly increase.. How quickly you guys forget the pictures on the Andial thread....

Great, ring out a extra 150HP on a "Stock" 993TT with no headwork, cams and just do it on boost!! Stock IC in Southern Cal heat..

Tim Wasmer

There was no forgetting as it was already in my car

You have to relear it when you remove power from the system and I had to do this yesterday thus the question of WHAT it is doing.

kojo911

http://www.iwsti.com/forums/perrinpe...ff-perrin.html

long but good summary of EBC function.