mbc help

[99 gst spyder]

i have a mbc that i want to put it in but i'm not sure where to tap it to anyone know?
what i thought is by tapping the outlet to the line that comes from the intake manifold to the bov and the inlet to the waste gate actuator is that right?
do i have to need a boost gauge to controll that psi boost?

 

[mattans]

You need a boost guage to see what you have changed the amount of boost to.

 

[awd6boltsi]

http://www.dsmtuners.com/forums/showthread.php?t=198327&highlight=taboo

This link should explain it and if it doesnt you could always search the forums and find out.
As for an aftermarket boost gauge... its a MUST when installing a MBC because the stock boost gauge is junk.

 

[Mr Peepers]

Yes, you will need an aftermarket boost gauge, the stock one doesn't actually read boost pressure, only what the ECU "thinks" it sees.

Tap the boost gauge into the fuel pressure solenoid/intake manifold line so you can see vacuum and boost before installing a MBC.

Then,
Unplug all the vacuum lines to your BCS(the solenoid that the wastegate actuator and turbo pressure source are tee'd into) but leave the electrical plug still connected. Plug the hole behind your MAS that originally had a line leading to the BCS. Hook the MBC up as shown in the diagram.

 

[Mr Peepers]

http://www.dsmtuners.com/forums/showthread.php?t=198327&highlight=taboo

In their diagram they tee into the BOV line, which is a whole topic in itself. I do not recommend it personally, and suggest using the nipple off your stock t25 compressor housing as the pressure source, and leaving the BOV line for the BOV.

 

[DSMunknown]

i have a mbc that i want to put it in but i'm not sure where to tap it to anyone know?
what i thought is by tapping the outlet to the line that comes from the intake manifold to the bov and the inlet to the waste gate actuator is that right?
do i have to need a boost gauge to controll that psi boost?

Do we really need to have this conversation again?? Click here. If you would like to have more photos, I will happily send them to you.

And yes, you need an accurate aftermarket boost/vacuum gauge, no matter what boost you plan on running with.

 

[MrBoxx]

Just a quick note: MrPeepers's diagram is correct, but if you have a TurboXS boost controller, the inlets and outlets on the MBC body will be reversed. TurboXS BC's have the pressure inlet on the side of the body, with the signal outlet on the bottom. They also adjust more or less backwards from the majority of MBC's out there.

 

[RedTurboEclipse]

I just had to comment since the big thread got locked.

I personally never dealt with MBCs because I've always been using EBCs. When I did deal with MBCs are with friends' dsms. I have always installed it with the T on the compressor housing/jpipe of the turbo.

I have never been able to compare and contrast with one that is T on the BOV line.. until now. We got a 2g talon with 6-bolt swap evo III gt turbo, etc etc. MBC that was tapped into the bov line. Sure it worked that way, I did notice boost spiked/creeped.

So today I drilled a hole in the jpipe put a nipple on there and redid the bov line and T the mbc on the new nipple I put on the jpipe. Boost seems more stable, no more spikes and lower than when it was connected to the BOV line, and I didn't change the setting on the MBC at all, just the install.

Just from MY EXPERIENCE with both, I'll always be tapping on the compressor/jpipe if I ever deal with MBCs again.

 

[strippedlug]

I just had to comment since the big thread got locked.

I personally never dealt with MBCs because I've always been using EBCs. When I did deal with MBCs are with friends' dsms. I have always installed it with the T on the compressor housing/jpipe of the turbo.

I have never been able to compare and contrast with one that is T on the BOV line.. until now. We got a 2g talon with 6-bolt swap evo III gt turbo, etc etc. MBC that was tapped into the bov line. Sure it worked that way, I did notice boost spiked/creeped.

So today I drilled a hole in the jpipe put a nipple on there and redid the bov line and T the mbc on the new nipple I put on the jpipe. Boost seems more stable, no more spikes and lower than when it was connected to the BOV line, and I didn't change the setting on the MBC at all, just the install.

Just from MY EXPERIENCE with both, I'll always be tapping on the compressor/jpipe if I ever deal with MBCs again.

Wow this is interesting. I was just about to post the exact opposite findings! I tee'd off the j-pipe because so many FAQ's describe this method as best (there is a wealth of knowledge out there on this topic). But I noticed a friend's MBC hooked up tee'd from the BOV so I tried it. I'm alot happier with the latter setup with my car. All in all I say try it both ways. Afterall there is very little labor involved so find what works best. I was truly surprised to find the BOV tee to work better to tell the truth. If you think of the fundamentals, seems to me RedTurboEclipse's setup and my initial would be the most reliable. But the difference is emmense on my car. I'm upgrading to a T50 on Thursday and I will again try both setups. Perhaps the turbo itself is the reason for my differing results.

 

[Mr Peepers]

Yes, there will be a bleeder hole on/near the nipple that is intended for the wastegate on all ball and spring type MBC's. This is to prevent the MBC from acting like a check valve and holding the wastegate open.

There are no advantages to hooking up a MBC through the BOV besides easy hook up instructions for vendors to cover a wide variety of turbo setups, and minimize calls concerning it. If you are bent on using a pressure source behind the throttle plate, at least leave the BOV alone and tap into the manifold itself, and check for boost leaks religiously for your turbo's sake.

 

[oldman]

Wow this is interesting. I was just about to post the exact opposite findings! I tee'd off the j-pipe because so many FAQ's describe this method as best (there is a wealth of knowledge out there on this topic). But I noticed a friend's MBC hooked up tee'd from the BOV so I tried it. I'm alot happier with the latter setup with my car. All in all I say try it both ways. Afterall there is very little labor involved so find what works best.

The more important issue in that debate really isn't about boost, it's more about proper functioning of the BOV, it fine if you insist on using manifold pressure, get a dedicated manifold source and leave the BOV line alone.

I was truly surprised to find the BOV tee to work better to tell the truth. If you think of the fundamentals, seems to me RedTurboEclipse's setup and my initial would be the most reliable. But the difference is emmense on my car. I'm upgrading to a T50 on Thursday and I will again try both setups. Perhaps the turbo itself is the reason for my differing results.

Worked better how?

 

[strippedlug]

The more important issue in that debate really isn't about boost, it's more about proper functioning of the BOV, it fine if you insist on using manifold pressure, get a dedicated manifold source and leave the BOV line alone.


Worked better how?

Sorry I should've mentioned. Better as in more stable boost throughout. I don't claim to understand it, It's just been a better setup for me personally. You have a great point about the BOV functionality though, and I will revamp this setup tomorrow first thing to give my BOV a dedicated source. Thanks I should've thought of that! Makes perfect sense

 

[99 gst spyder]

Do we really need to have this conversation again?? Click here. If you would like to have more photos, I will happily send them to you.

And yes, you need an accurate aftermarket boost/vacuum gauge, no matter what boost you plan on running with.

here i have a T which is T from the jpipe, the wg acutaor and this one wire harness solonoid

by looking at the stock before doing anything, it was already T in some sort of way, then i took the T out and add in the MBC from the j pipe turbo going into the WG actuator but i still have that other tube connected (at the T that i took out) to some wire harness soloniod, do i just leave that unhook to anything or am i suppose to T it with the MBC

so now i have a straight line going from the j pipe to the mbc and from the mbc to the wg actuator is that correct. i will end up with another line that i took off from the T in the beginning.

i try that setting

i went for a test drive and it didn't seem right b/c the bov sounds weird now and there's some sound sounded like a whistle when i'm on the peddle then when i let go, the bov sounded wierd and i'm not sure what's wrong.

can you help me out here

thanks in advance

 

[Mr Peepers]

Did you get an actual boost gauge and hook it up before you put the MBC on? Please say yes.

Otherwise, that sounds correct, there should a be a line(actually 2) between the J-pipe and WGA with teh MBC in the middle. The extra line leading to the wiring harness solenoid(which is the boost control solenoid/BCS) can be unplugged, it is not needed. The other line from the BCS on the other hand should either be plugged, or traced to where it connects to(just behind the stock MAS) and plugged.

Some MBC's whistle a little from the bleeder hole right around full boost, my SBR ball a spring type did until I routed I routed the bleeder hole back into the intake.

If the whistle is only when you let off the gas, it's most likely your BOV. You are probably hearing it now with more boost to release.