you can increase over the mechanical spring..if you vent the boost going to the wastegates with the n75 valve.

the start boost depends from the springs in the wastegates and the adjusting from the rod. The boost opens the wastegates at the adjusted point....the ecu with his n95 valve vent the boost, so the wastegates open later.If you disconnect the valve from voltage, it is open to the wastegates (to open it at the start boost) and closed to the vent...(so in winter you must drive with disconnect...)

and i must agree marksi..if you try to adjust a stiff spring to lower boost as its possible...the wastegates bleeds open..

maybe the n75 valve is to little for regulating the two turbos without lag in regulation circle with stiff springs(and lag in this circle produce a overboost)..a ebc is quicker with his greater valve

 

What makes no sense? I will try to clarify for you...

please tell me how if you have 1 bar actuators that you can run below 1 bar without a boost leak? It is physically impossible as the wastegate will not open until it reaches 1bar(no matter what the ecu tells any valve or solenoid). Unless you want to run CO2 to the actuator, it isn't going to happen.

I say it again. The ECU cannot run lower than the mechanical limit of the actuator and if you go with stiffer actuators, you need to retune the ecu. Duty Cycle needs to be tweaked for different setups.

I think you are gravely mistaken about how the entire system works.

Justin

 

Hmmm...so an unflashed car hits .7 which is lower than the mechanical limit of the wastegate....please explain?

 

The stock wastegates are setup for .7bar... When you add a 1bar actuator to a car that is not flashed the boost will be raised because there is no way to lower it below that point.

 

Because 10lbs will not overcome and open a 15lb spring.

 

unless....your backpressure is sky high

that is the ONLY way a wastegate will open before the rated spring pressure (which are rated at 1:1)

 

Wait...you mean if I add a 1 bar wastegate to an unflashed car I will get 1.0 boost....really?

what about timing and fuel?

 

yes, any solenoid, controller etc etc will only delay the signal, increasing the boost

 

learn something new every day...LOL

 

YESSSSS... I think you got it now.

If you add a 1 bar actuator to a stock car, it will run 1 bar as that has become the new mechanical minimum.

BTW, you still need to adjust timing and fuel to take advantage of the newfound boost.

Justin

 

The bleed valve allows the boost to be raised over the spring pressure because it prevents the spring from seeing the pressure it cracks at. As you approach the pressure you WANT you allow the W/G valve/spring to see more pressure - and it opens. So, if you have a 1bar spring you cannot go lower but you can go higher, sometimes way higher!

 

The boost is set by the spring and the preload.

You said "this is the lowest boost the ECU can regulate"... not true. It is the highest boost- all the ecu can do is pulse the N95 to send a 'release boost signal'

 

my english is not the best....but for my knowledge the boost system works following

the spring and his adjustment controls the lowest boost , (backpressure reduce the start boost that is adjusted with spring and rod at high loads) ....the ecu is only able to increase boost from start boost...so the lowest boost that the ecu can regulate is ? adjusted boost minus backpressure, the highest boost depends on what turbos you are use and what springrate and backpressure this turbos have....and the ecu must be programmed to this boost if the mechanical system is able to achieve this boost

 

that is the full pressure signal. full pressure = minimum boost in an actuated setup.

The machanical minimum(all valves removed) is the wastegate actuator spring pressure. In an ACTUATED setup, you can then create a controlled boost leak to the actuator to RAISE the boost. Rather than explain all of this, I would just say to research how it works first.

The ECU "releases boost" to the atmosphere to raise pressure. If the power to the solenoid is removed, you default to spring pressure.

Justin

 

Wrong.

The only thing the wastegate can do is OPEN SOONER. The pressure from the N95 valve is acts against the internal spring. Add pressure and the spring 'sees' the boost+ acutator pressure. Without any actuator pressure it opens at whatever the mechanical spring is set to. Add actuator oressure and it will open at "spring presure minus actuator pressure":

Boost = Spring pressure - Actuator signal pressure.

From a purely mechanical viewpoint... in a static situation.

(People may ask "how do I see 1.3 when my wastegate is set to 13.5lbs?" ... Volume. As you increase the air volume the 'cracking pressure' and the 'sustained boost' will be different. )

I cannot understand how you guys are saying boost that is ejcted past the wastegate out the exhaust is somehow used to then increase boost.....

If tony or kevin want to jump in and correct me, I'm all ears.