I run my external wastegate vacuum line directly to my compressor side of my turbo. This makes it a bit easier, but it would still work if it was routed to the intake manifold.

As we all know my boost controller is in the middle between the wastegate and compressor.

We put a boost control solenoid in parallel with the MBC. Basically the vacuum line running to the wastegate has a "T" in it. This allows two separate lines to be attached to the one vacuum line. One line goes directly to the MBC. One line goes to the BCS. Then we put a vacuum line on the compressor side of the turbo. We installed another "T" in the line. We ran a new vacuum line to the other connection of the MBC. We ran the other line to the other connection of the BCS. Basically the single line splits and goes to each respective component and goes out of each respective component and back into one line again(parallel operation).

This takes care of how these components are setup. I will not take you into each step of wiring something up, but if someone needs help, I will explain that later. I think this is pretty straight forward.

The BCS is energized open and deengergized closed. The positive side connection of the solenoid is the same side that the mitsu symbol is on.

We used a two positon switch. Power is tapped off the cigarette lighter power(ACC) to the switch. Then that power wire is routed to the positive side of the BCS. The negative side of the BCS is routed to the negative terminal on the battery. When the switch is placed "on"(red guard is in the up position-then switch is pushed up), the BCS is energized open to allow air to flow from the compressor to the wastegate. When the switch is "off"(red guard is slapped down) the solenoid deenergizes closed and air stops flowing through it.

Remember air will take the path of least resistance. When the solenoid is open my boost setting depends on my wastegate spring(6 psi in my case). When the solenoid is closed, the boost setting depends on my MBC, because now it has the least resistance.

I can see that a ball/spring type boost controller would be the best thing to use when using this setup.

I am not sure if a bleed only boost controller will yield the same results. It might though.

I have a Turbo XS High Performance MBC. It used a ball/spring and a bleed for fine adjustment and to allow the turbo to spool faster when attached to the compressor side of the turbo. My point is that I got 6 psi in my low setting and 10 psi in the high setting. This really works damn good.

I plan on playing with the bleed side(small adjustment) and see if the boost will raise or lower a bit(with the BCS open/low setting). I cannot completely close it off, but there is probably 3-4 psi of adjustment just from the bleed port. Before I had an intercooler my turbo went straight to my intake manifold. The wastegate stayed rock steady at 6 psi after everything warmed up. Now with my setup, I am getting 6 psi on the low setting(like I have no MBC) and it should be 4-5 psi due to pressure drop in the system with the front mount. This tells me that my bleed is raising my boost.

I did practice this earlier before it started rainging and I have never had better launches. I can launch at a higher rpm and hit WOT in 1st gear, then shift to second, let out the clutch and hit WOT, at that time I tap the guard down and it rolls into high boost. Nice and smooth, without shock to the drivetrain. I did not break traction what so ever all the way to redline, because I was already accelerating. Between shifts.....well you know what happens.

You could also use two ball/spring boost controllers with this setup if you wanted. One would be in series with the BCS and the other would be routed in parallel as I have above. This would give you infinate adjustment of the low setting(above wastegate setting of course).

I spent less than $10 on parts. I already had the killer aircraft switch/guard and the BCS.

Comments/feedback?

If you guys need the part number for this, I can look on my extra BCS and will post that later.

I have the same setup, except im using the vacuum solenoid off a 300zx.

You can even add additional solenoids and mbcs for multiple stages

We had a discussion a while back on the subject. I remember a supra TT BCS was discussed, but nobody knew if a mitsu BCS would work. I do remember someone said they used a 300ZX. I could not find one in the area(over $100 at dealer). So, since 1G stuff is plentyful I went this route. I also wanted a BCS that energized open and deenergized closed. I really did not want to send power to this while driving 99% of the time. I always drive in high boost setting. I just want the low application for launching from a stop.

These are everywhere in the marketplace. Anyone who adds a boost controller to a 1G, removes this. Unless they are doing this http://www.ppg.trends.ca/vfaq_bcs.htm

I like having the dash control personally.

I plan on taking some digital pics of the setup under the hood and my mounted switch so people have something to go by.

I love 2gnt, I could not have done it without the help from you guys.

Good writeup Deano!

Yea, im only using the 300zx one b/c i got it free. otherwise you can get the dsm bcs's for a couple bux anywhere :)

as for the 300zx solenoid, it works the same way, no power and im on high boost, power to the solenoid,and im on low boost