BT Question....n75 with external wastegate?

[billab0ng98]

Is there anyway to use the n75 while running a 38mm tial wastegate? if so how would I run the lines? THANKS!

[A4 TSCHUSS]

the same way you would to a mbc.

The line coming off the nipple on the turbo outlet or intercooler pipe would go to the inlet of the N75 and then the outlet of the N75 would go to the wastegate nipple. Then of course the longest nipple of the N75 goes into a intake pipe to the turbo.

[A4ringedONE8T]

the same way you would to a mbc.

The line coming off the nipple on the turbo outlet or intercooler pipe would go to the inlet of the N75 and then the outlet of the N75 would go to the wastegate nipple. Then of course the longest nipple of the N75 goes into a intake pipe to the turbo.

Just like that except connect the part of the N75 thats normally in the TIP to the top port on the WG

[A4 TSCHUSS]

Why would you do that? Isnt the top port used in conjuntion with the side port when using an electronic boost controller? Why would you want leaking air (boost let by out the 3rd nipple of N75) being put into the wastegate? The top nipple is vented when using a mbc dont see why you wouldnt do the same with the N75. I think it will work different ways though.

[A4ringedONE8T]

Why would you do that? Isnt the top port used in conjuntion with the side port when using an electronic boost controller? Why would you want leaking air (boost let by out the 3rd nipple of N75) being put into the wastegate? The top nipple is vented when using a mbc dont see why you wouldnt do the same with the N75. I think it will work different ways though.

Alright well, think of it this way, the N75 is a boost controller right? And it is electronic right? ... its no different than an EBC, the ECU is just the "controller" and the N75 is the solenoid. You would hook it up as you advised for the side wastegate port and the boost signal line, just put a line from the long nipple on the N75 to the top port on the wastegate. It will work without it but the WG will have much quicker response and less creep hooked up as I said

[billab0ng98]

thank you for the responses...will both ways work?

[A4ringedONE8T]

thank you for the responses...will both ways work?

Yes but I would advise the way I explained

[F16HTON]

You must use a 1.0 bar wastegate spring.

[A4 TSCHUSS]

Who Shawn?

[A4ringedONE8T]

Who Shawn?

No to use the N75. The stock WG is around 1bar so inorder to keep the ECU in check, you would need to run the same in the external WG

[audikid66]

kyle why would u run a n75 anyways with ur new turbo... bypass and run a EBC or MBC

[billab0ng98]

why kenny?

[billab0ng98]

ok hooked the n75 up but now its boosting 25+ psi on the revo bt 550cc file.....should i turn it down through lemmiwinks since im not using a mbc?

[A4ringedONE8T]

You cant change boost with lemmiwinks. Change the REVO boost setting with an SPS

[billab0ng98]

anyone got an sps in the jersey shore area?? lol

[diagnosticator]

anyone got an sps in the jersey shore area?? lol

How did you connect the N75? I agree with "A4 TCHUSS", connect the valve that way and leave the top port of the actuator vented to atmosphere.

The way the N75 controlls boost, it lowers the control signal air pressure from the compressor, and keeps the waste gate closed until the specified boost pressure is acheived. The method used by the N75, it pulses open and closed at high speed, and bleeds part of the boost pressure off to the compressor inlet pipe, bleeding more or less boost pressure as needed to open the wastgate or keep the WG closed as needed. The boost pressure regulation should be the same regardless of internal or external waste gate.
The "long" N75 port, is the bleed to atmosphere port. If that port was connected to the top port of the actuator, the pressure bleed from the control signal pressure, would oppose the control signal in the actuator, but more importantly, the N75 won't be able to control the amount of control pressure applied to the bottom port of the actuator, because the bleed function can't work if connected to a dead end, it must be allowed to bleed air to atmosphere.

[F16HTON]

The N75 does not have a vent to atmosphere, it vent into the TIP because modern emissions will not allow any of the intake system to vent to air (everything is recirculate back into the combustion chamber)

Tial recommends that if you are using a electronic boost controller, that the vent tube from the solenoid be connected to the top port. This allows the wastegate to function more quickly as the vented air helps close it.

[diagnosticator]

The N75 does not have a vent to atmosphere, it vent into the TIP because modern emissions will not allow any of the intake system to vent to air (everything is recirculate back into the combustion chamber)

Tial recommends that if you are using a electronic boost controller, that the vent tube from the solenoid be connected to the top port. This allows the wastegate to function more quickly as the vented air helps close it.

By "atmosphere" is in the turbo inlet pipe, the air pressure there is ~ just below ambient air pressure.

The recommendation from Tial regarding connecting the bleed port of the typical aftermarket EBC, does not apply to the N75, it cannot and will not function properly and won't control the boost pressure control signal to the actuator if the bleed port is connected to the dead end at the upper actuator port.
If the pressure bleed is connected to the upper chamber of the actuator, it is then effectively blocked off, and can't regulate the control signal pressure to the WG actuator, it's the same as if the bleed port was capped at the valve, except the control failure will be delayed instead of instant. The delay to failure of control, will depend on the volume of the actuator chamber, maybe a half second, but in the end the result is full boost pressure applied to the bottom of the waste gate while at the same time, the pressure at the top chamber increases opposing the pressure at the bottom port trying to open the WG. Regardless, there will be a failure of boost regulation if the bleed port of the N75 is connected to the upper WG actuator port.