A picture speaks a thousand words. Ok, so today I installed my Turbotech V2 manual boost controller. The Pic below explains how I did it. Essentially, run vacuum hose from the nipples at the bottom of the intake pipes to a T piece. Then from the T piece to the inlet of the boost controller. Then from the outlet on the boost controller, to another T piece which joins the vacuum hose going to the actuators. The problem I'm having is that with this setup I seem to have unlimited boost. On a quick test run, I hit 15 psi very easily. Bad. This is with the adjustment screw pretty much all the way out that I can blow through the boost controller with my mouth. If I take out the boost controller and essentially join the inlet and outlet vacuum hose with a connector (essentially bypassing the boost controller), I get a nice steady 9 psi stock boost. So things to note: I havent disconnected the factory boost solenoids as some folks have told me that I dont need to. Is this incorrect? I might expect a small boost spike but would leaving the factory solenoids connected allow unlimited boost? Also, on the back of the boost controller is a tiny little hole. Apparently, this small hole in the valve body (called an "excess pressure valve") allows pressurised air to escape from between the controller and wastegate actuator following a boost event. This pressurised air would otherwise be trapped against the wastegate actuator and cause poor boost response. Could this escape of air be causing the problem?
When you say you haven't disconnected the Safety Boost Solenoids, do you mean you haven't removed them from the plumbing works or haven't disconnect their connector? If you haven't disconnected the plugs for them (2 of them, very easy to reach / see), I recommend doing that to rule them out first. I've never used an MBC before, so can't definitively tell you how they will react with the Safety Boost Solenoids. In theory they shouldn't have any effect, because MBCs do the same thing Boost Jets do, just bleed less air past, with the exception and MBC can adjust to some degree how much, and my Zed was running with Boost Jets (actually dangerously over-boosting, because the clown before me had 2 pairs of boost jets installed ) when I first bought my Zed with the Safety Boost Solenoid system completely intact. I know EBCs HATE the Safety Boost Solenoids, because the control boost differently. I remember installing my EBC and running into all sorts of bizarre boost problems. Disconnected the 2 connectors, instant fix, till I got around to removing the Safety Boost Solenoids altogether and running a new straight line from Actuators to EBC Solenoid. Ideally you should at some stage run brand new lines straight from Actuators to your MBC at some stage in the future. MoulaZX
No... No, I have not disconnected anything. So, the plugs are still connected as is all the plumbing. I left them connected, because like you say, I wouldnt think they would have any effect with a MBC.
I agree, but its only a 2 minute test, so figure its worth a shot. Don't have to remove anything to get at them, just pop bonnet, find plugs (around Strut Tower areas), disconnect, close bonnet, drive. According to your diagram, you have it plumbed up correctly. Assuming the IN & OUT ports aren't the other way around... and that you've actually plugged all the pipes into the correct ports/nipples on the car itself, lol. MoulaZX
When i hooked up mine i disconnected the safety boost solenoids and all worked perfect. I decided to hook them back for some reason and i then got a massive boost spike ( still don't know why ). Disconnected and been 100% o.k ever since.
You dont disconnect the safety boost soleniods with an MBC make sure the ports on the controller are the right way round
Yes you DO disconnect the factory boost solenoids when you plumb in any other sort of boost controller, otherwise you have 2 systems working against each other. I think the key point in your post is that you are turning the adjustment screw the wrong way. If all the way out givers you 15psi the logic tells you to turn the thing the other way to reduce boost. The controller is basically a valve to regulate the air supplied to the wastegates. When the required boost is reached the air opens the wastegates bleeding off the excess. A bit more reading on how turbo systems work and maybe a bit of research on your paticular controller will help you make more reasoned and logic decisions
yours might work differently like mine does, wind it IN for more boost and out for less. mine also has the wastegate pipes going into the bottom of the controller.
Wrong, Wrong Wrong AN MBC doesnt have any feedback of what the restrictors are doing. And EBC does. You dont pull the solenoid controls when you use a manual controller then safety boost still works in an Z32. This cant be done with an EBC as it will still try to get your target boost when its in safety boost. So the safety boost soleniods have to be discoonected. If you are NOT talking about a z32 then you would be correct. Most other cars use soleniod valves to actually control boost level. In a z32 this is done by restrictors in the boost feed line. In a z32 the soleniods only work to bring on safety boost which is abiut 4-5 psi.
This... Failing that, undo the top screw completely and have a look inside. Ive had a spring jam from it being screwed too far in before. Should be a ball and spring. Ball on the bottom, spring on top.
Yes you DO need to disconnect the connectors to the boost solenoids you noobs. Unless you disconnect them you'll get boost spiking up the ass. Your wrong when the solenoids are open ie active 12v they lower what the wastegates see by bleeding off pressure. Bleeding off pressure back to the intake tract increases boost. For safety boost to be active they're switched off no 12v applied so the waste gates see full pressure and open at 6psi. Because the mbc is in front of the stock boost solenoids and doesn't open until pressure is high enough when it does so open and passes by the stock boost solenoids unless they're unplugged no 12v applied (closed) they'll bleed off more boost and it spikes like hell. You do not need to remove the hoses or restrictors because the stock restrictor is not in the hose from the boost source to the waste gate but is in fact located from the T piece to the stock boost solenoids. Simply disconnecting the 12v signal to the stock solenoids will stop boost being bled off. This is why you have unlimited boost. The MBC is working correctly but the stock boost solenoids further up the line closer to the waste gates is bleeding off pressure, directing it away from the waste gate actuators and keeping the waste gates closed. Safety boost off = 12v applied to solenoids Safety boost on = no 12 applied to solenoids I hope this clears up all the confusion once and for all. Alex.
The way to do it is connect, T the lines from the mbc directly to the actuators, and cap the stock set up off, end of all problems.
There's no need to do this so long as the solenoids have no power source. Btw, the term "Safety boost solenoids" is very misleading, they're actually what brings the Z32 up to 9psi. Without them active you WILL be in safety boost unless you have a MBC/EBC. We're only talking boost here, not actual safety mode which runs rich ect so no one gets confused reading this.
Best and easiest failsafe way is to run 1 hose from the plenum to the "in" port then run 2 equal length hoses directly to the wastegate actuators.
This is taken from the tech section.. http://www.pexcom.com/images/turbotech.pdfturbotech.pdf It does stat to disconnect the boost control solenoids by disconnecting the plug to them. If they are still connected you will have boost spikes..
What drugs are some of you guys on?? Use some logic. The safety boost soleniods are ONLY actuated when the engine is cold or the car detects detonation and the ECU switches them on/off. You dont need to disconnect them physically or electrically with a MBC. END OF STORY. The restrictors are what controls boost there are NO spikes caused by the soleniods CAUSE THEY ARE NOT CONTROLLING SH!T when the car is running properly. They are CLOSED. Its irrelevant whether the soleniods have 12v on them or zero at any time. THEY ARE CLOSED during normal operation and there is nothing to tell any part of the system what boost you are running. Boost spikes implies the somleniods are working during normal driving. THEY ARNT, THEY ARE CLOSED. The restrictors are brass drilled inserts. They are dumb, The MBC will still control boost with NO spikes even if they are connected. There is no feedback of boost level to them when the car is in SB. The MBC just controls boost over the top of the restrictors. Like if the restrictors had smaller holes. Smaller restrictor holes equal higher boost. An EBC will continue to try control boost regardless of what the SB soleniods are doing. So if the car is in safety boost the EBC will measure the current boost level and continue to try to adjust it to your preset THATS WHY YOU PULL THE SB PLUGS WITH AN EBC installed. Thats how you get boost spikes. If you have an MBC and boost spikes. It has nothing to do with restrictors or SB soleniods being connected. With an MBC you should try to continue to use the SB soleniods as it STILL LETS THE CAR PUT ITS-SELF into SAFETY BOOST if the ECU detects an issue. Thats one of the drawbacks of an EBC. No safety boost on detonation. Just engines being destroyed and puts the responsibility of detecting detonation and taking your foot off the accelerator back onto YOU Having said that. I dont have ANY of that crap in my car. Just an MBC directly controlling the actuators. Too messy to reinstall after the engine rebuild. I just dont thrash it cold.
Wrong mate. Each side of the engine has this setup. The wastegate is PRE-SET to open when seeing a boost signal of about 6-7 psi, while the setup is "calibrated" to run the engine at about 9-10 psi of boost. When the factory boost solenoid is OPEN (12v signal) the actual boost signal is bled off through the solenoid into the intake tract... So, the wastegate actuator sees less than actual boost pressure (about 3 lbs less). If you were to plug the line (or remove the solenoid) and have a direct boost signal, the boost would be limited to 7 psi. When the factory solenoid is closed (12v signal cut [safety boost, cold engine, or startup]), you see about 7 psi max boost because the actuator is receiving the actual boost signal pressure instead of the "calibrated" signal. This is where the MBC comes in, the turbotech wont open until its reaches set pressure. Its in place between the boost signal and the T-piece, the boost solenoids are AFTER this and if left connected will bleed off the higher pressure created when the turbotech opens and you hit what seems to be infinite boost and spiking. (normal operation) (12v applied) (in SAFETY BOOST) (no 12v applied)
Nice diagram, BUT you are missing a restrictor. There is 2 in each system/side. The second is in the boost line. The restrictor you illustrated is the one that allows the car to have some boost pressure in safety boost approx 4-5psi. The one you missed out is what actually sets the boost level and is in the boost line. Next time you pull this apart, count up how many yellow stripes are around the hoses in there. Each stripe is where a restrictor sits. The safety boost soleniods do NOT OPEN AND CLOSE to control boost level of 9 psi which is what must happen if your diagram was to work to control boost. Z32 doesnt work like that. A restrictor controls Boost level and its in the boost line. The SB soleniods work only DURING SAFETY BOOST (starting and during detonation) and are closed 99.9% of the time. So that safety boost line and restrictor dont do squat in normal operation. They are shut off Forgot to mention, if you use an MBC you are supposed to put a very small hole ( needle sized) in the actuator feed line so air pressure can bleed out of the pressurized line after the MBC has closed it off. This stops spiking due to pressure remaining in the actuator lines after they have opened.
