Just got my first 240SX! - Only makes 5.8 psi boost?

[carbully]

Tulsa_S-13, what happens when there is no control solenoid installed, but the WG is plumbed straight in? I am only getting .4 bar/5.8psi and this might be my problem.

Alternatively, I noticed that the bottom port on my TB is left open to the atmosphere, could that be causing my low boost?

[Tulsa_S-13]

You need to cap that nipple off on the throttle body, that would cause a vacuum leak.

Connecting a line directly from the wastegate to a vacuum source on the TB should give you 7psi. It is possible that you have a faulty wastegate actuator that needs to be replaced.

[carbully]

Ok, but under boost wouldn't that vacuum leak become a boost leak?

[carbully]

And assuming I fix whatever is giving me low boost, when I want to stuep up to 10psi I need either:

A- one of the stock boost solenoids and an unrestricted hose

or

B- an aftermarket boost controller

Right?

[danstachet]

you are correct... but i dont see that little port giving you that much of a boost leak. and i recommend the Hallman Pro boost controller. i have it and its awesome

[notslow]

if you are ghetto like me you can build a boost controller for less than 3 dollars that works perfectly fine

[Jadesr20det]

if you are ghetto like me you can build a boost controller for less than 3 dollars that works perfectly fine

home depot boost controller!!!

[carbully]

What if I was really ghetto and ran nothing at all, no solenoid or controller, just the way I bought the car? Is that bad? I am currently getting 5.8lbs of boost with no controller or solenoid, is that why I am getting so little boost?

[Tulsa_S-13]

Like I already said, it'd be fine. You'll just be limited to 5.8psi.

My sn is Tulsa S13 if you have anymore questions.

[carbully]

If what you are saying is true, the stock WG must only do like 5.8psi (.4 bar) and the stock solenoid/restrictor hose must function like a boost controller bleeding off some pressure to increase boost to 7psi. Does that seem accurrate to you guys?

[redtop91]

Nah as far as I remember the actuator has a 7 psi or greater spring.

[CMG]

Ryon used an Apex'i AVCR to control boost. I however did use the boost solenoid in my swap, although now I'm running Ryon's old AVCR (Thanks!).

Using the solenoid I was still at 7psi, it wasn't until I stumbled upon this article and replaced the restricted line with a standard vacuum line that I was able to hit 10psi.

http://www.nissansilvia.com/fo....html

I have read a few post were people using the solenoid have seen 10psi, but I'm not sure whether they were using the factory lines or what they had laying around.

Ahh, well that explains something cuz I replaced all my vaccum lines with Akimoto hose, so I must have inadvertantly gotten rid of that restrictor one without even knowing it.

[redtop91]

Ughhhhh that's what I was saying all along.

[carbully]

Ok, then one last question. I still have the stock KA exhaust on the car. Could that be restrictive enough to cause my boost to max out at 5.8 psi?

[redtop91]

Nope. The amount of boost you develop is not affected by exhaust. You won't make as much power with that boost on a restrictive exhaust but you'll make as much boost as the actuator is allowing.

[CMG]

Ughhhhh that's what I was saying all along.

My bad, I wasn't understanding.

[idahotuner]

free post YAY