Before I start I have searched many times. I am pretty sure it hasnt been asked before. I had a second hand engine fitted about a yr ago now by a so called "reputable" z specialist. When i picked the car up they showed me a dyno chart and told me my car was running on stock 7psi boost. I questioned this immediately because i know from reading that they should run on 9 psi. Anyway he tried to tell me it was 7 stock so i left it because i already was not happy with the work done. Anyway when they fitted the engine they removed the 2 solenoids on either side of the plenum, and the prvr i think it is and the aivs. I dont have any codes but i have not checked the temp sensor yet. My question is does removing any of these solenoids cause the car to run stock 7 psi. I need to know because i want to fit a boost controller but if the computer is in safety mode i am worried that i may damage something by fitting the boost controller. Wanting to set boost to 12psi. Any help is greatly appreciated.
Those 2 solenoids are the boost control solenoids, with out them you have 7 psi. With them you have 9 psi unless there is a fault to induce safety boost. Get a consult scan done on your car to ensure there are no electrical fault codes, then fit up you boost controller, 12psi on a healthy engine won't be any issue. You can also use the paper clip method to check for errors, look in the tech section for it under diagnostic error codes or something Edit here it is http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.418
Yes you need the solenoids to run 9psi, thats what they do. If you fit a boost controller you can get your 9 or 12 psi back. Not a big deal really. Whoever told you 7psi is stock must be a newbie. Without them your wastegate actuators are seeing full boost without bleeding anything off via the boost solenoids which is causing your 7psi.
well they dont call themselves newbies. fairly well recognised people in the 300zx world. Yes i have checked codes, I have access to the actually nissan consult computer as I work at a nissan dealership. I thought those 2 solenoids were the safety boost solenoids but I wasnt sure if removing them made the car run on 7 psi. Thank you for your help. greatly appreciated.
When they're off (no 12v) they make the car run in safety boost which is 7psi, when they have 12v applied the car makes 9psi. Really they're the stock electronic boost controller, the term safety boost solenoids can be a bit misleading. This is why when people fit a MBC its best to disconnect the stock boost solenoids, they'll try and bleed off the extra boost because they're located after where a MBC sits, its why people get boost spiking with a mbc when they DONT disconnect their stock electronic boost control.
so because my boost solenoids are disconnected I should be able to just hook up my mbc with out worrying about boost spiking?
Sorry to hijack the thread. I'm currently putting my engine back together with new T28/25 hybrids (look almost stock) with 10psi actuators. Should I just leave these solenoids out?
Yep, yours could just have a hose straight from the actuator to the boost controller without the T piece to the stock solenoid. Yours would look like this except a MBC in the exact same spot. then a T piece to both actuators off the one MBC. Removing them has the same result as disconnecting them, when the 12v is disconnected like in my car they are closed which stops them bleeding off into the intake tract. Solenoids only do two things, on and off.
Yea if your using an EBC then you can keep the stock solenoids connected so the car can go into safety boost, if its a manual boost controller then might as well leave them off.
my 91 tt when imported from japan was dynoed and mechanic said it was the fist one he has seen under 9psi and had the best a/f ratio he had ever seen acoss the rpm range an was left like that
