MBC hookup help please

[nolimits]

91 GSX--I've tried 2 different hook-ups with 2 different results...neither of which I wanted!! It's a standard ball & spring with the parallel port (I'll call #1) and the perpendicular port (#2).

I connected #2 tee'd from the line between the wastegate and the IC housing (where the factory boost limiter was). #1 was tee'd from the BOV line. factory boost controller was disconnected all together and set aside. Results: 10psi regardless of MBC setting.

Then I removed the line from the IC housing to the wastegate and hooked #2 up directly to the wastegate (plugging the housing fitting). Results: full boost regardless of MBC settings (I wasn't about to find out how far it was going to go!!)

What am I doing wrong???

 

[patriot]

Originally posted by nolimits
91 GSX--I've tried 2 different hook-ups with 2 different results...neither of which I wanted!! It's a standard ball & spring with the parallel port (I'll call #1) and the perpendicular port (#2).

I connected #2 tee'd from the line between the wastegate and the IC housing (where the factory boost limiter was). #1 was tee'd from the BOV line. factory boost controller was disconnected all together and set aside. Results: 10psi regardless of MBC setting.

Then I removed the line from the IC housing to the wastegate and hooked #2 up directly to the wastegate (plugging the housing fitting). Results: full boost regardless of MBC settings (I wasn't about to find out how far it was going to go!!)

What am I doing wrong???

is this one of those home-made home depot mbc's? if so, if you have i turned wheree the ball falls into or gets caught on the lip of the perpendicular port, then it will only give you a constant psi, in your case 10. this happened in my talon also. my remedy: pull the mbc apart, make sure the ball isnt in the perp. part, and support the mbc so that the perp part is pointing towards the sky. i also had the problem of a small gash in my line from the parallel part to the wastegate actuator that was giving me probs. hope that helps!

 

[nolimits]

It's not the ball or spring...that seems to be fine. What is the correct way of hooking this up?

 

[patriot]

Originally posted by nolimits
It's not the ball or spring...that seems to be fine. What is the correct way of hooking this up?

http://www.carreview.com/projecteclipseboostcontrollercrx.aspx

 

[nolimits]

Still doesn't help. I viewed the Buschur Install on the vfaq. Is the MBC hooked directly to the wastegate with the line to the pressure fitting above it disconnected and plugged....or is it just connected to the T like the BCS was?

 

[scuRRed whiTey]

| |
| |__
| <---too wastegate
| |---
| |
|O|
---

^

too blow off line that goes to intake mani-fold

its as easy as that....

make sure u plug up the old hose holes and get rid of ur BCS(boost solenoid)

i made one and i can get any kind of boost out of it...not just 10 psi...make sure u have a bleeder hole in the mbody too

 

[nolimits]

I know it goes to the wastegate, and the BCS removed...but is it T'd between the wastegate and pressure fitting...or is that fitting plugged and MBC hooked solitarily up to the wastegate?? (either way it's hooked to the wastegate...which way is correct??)

 

[Trctnless]

Try this. Don't use any T's.


Knob
[ ]
[ ]
[ ]
[ { >>> to Wastgate
[ ]
O
___

TO nipple on turbo compressor outlet elbow. <<< That way your getting an absolute preasure signal from your turbo to actuate the valve.

 

[nolimits]

Originally posted by Trctnless
Try this. Don't use any T's.


Knob
[ ]
[ ]
[ ]
[ { >>> to Wastgate
[ ]
O
___

TO nipple on turbo compressor outlet elbow. <<< That way your getting an absolute preasure signal from your turbo to actuate the valve.

Tried it...full boost. Then I tried replacing the line from the compressor outlet to the wastegate, leaving the T in and uncapped. No boost controller...I figured that would be a limited leak (which is basically what a boost controller does without the adjustment). I nailed 15psi. That will work for now, but is my MBC bad? Visually it seems good...I blew through it with an air compressor and it took very little pressure to unseat the ball and pass air. It's a homemade job I bought off ebay for around $11 from a place called "SRP". They were selling them and people seemed content so I picked one up. I guess maybe I'll get the JoeP and see if it works better!

 

[nolimits]

I noticed that the pic of the ebay mbc that I bought shows to back out the screw for increased boost. Mine shows the opposite. Which is it? I assumed screwing it in would increase spring tension = less air flow from compressor fitting = more boost. Is this right, or have I got it backwards!!

 

[2GeNTSi]

I just installed mine today. I completely took out the bottom BCS hose (that one that splits to the compressor housing and to the wastegate actuator) I capped the BCS nipple that the hose was on and the nipple that's on the compressor housing. The top hose on the BCS I still have going to my intake even though it probably serves no purpose.

I then got the hose that had a tag which said "To turbo wastegate" and plugged in directly into the wastegate actuator nipple. Then the other one that said "To BOV" cut the top line of my 1g BOV and teed it there.

I was not able to mount my MBC on the radiator support like most, mine is the dejontool dual-stage one and it has this solenoid that makes it a little different to mount, on a 1G it'll mount fine but not on a 2G. I ended up messing with the bracket and mounting it sideways above my cone filter.

I didn't have much time to test it out because I had work but everything seems to be working fine, need to adjust the stock level though because it was still going up to 15psi. I'm not sure how much to loosen it though, I think 1/8 turn is 1psi so I will turn it 180 degrees from where it is to decrease it hopefully 4psi. Then tomorrow I will hook up the toggle switch to go from stock boost to racing boost. If everything works out fine I'll make something in photoshop to show my setup.

 

[Defiant]

.

 

[2GeNTSi]

yeah that is how mines setup. I was messing with mine today to lower the boost but it wouldn't lower as far as I can tell. I turned it half way, and then 1 1/2 turns, and it maybe lowered it 2psi. I'll try loosening it some more but it looks like the knob might come out .

*EDIT* I went ahead and loosened it almost all the way and still it is sitting at 12psi at lowest. I don't know what's wrong with it if anything, the only part I don't have hooked up is the solenoid that the toggle switch hooks up to but that shouldn't matter.