Issue with new MBC

[wintertidenz]

Okay, call me a muppet but I'm having some issues with my MBC. Bought it today and plumbed it in how I thought it should be in there (no manual came with it) - car spikes up to 14 pound then settles to 9-10psi.

Adjusting the MBC does nothing, and I have tried taking the ball and spring out of the t-join. This just made it spike then settle back to 7psi.

Taking the t-join out and putting the MBC in with the arrow pointing towards the wastegate makes it just boost uncontrollably, so I took it out and turned it around. Adjusting it doesn't make it work any better or worse.

I returned the setup to how I first had it, so for the moment it's boosting 10psi and seems to be OK.

See attached pics for current setup - now how the hell do I set it up correctly?

http://i100.photobucket.com/albums/m...0386resize.jpg
http://i100.photobucket.com/albums/m...0385resize.jpg

[Turbo_Steve]

Try putting the big blue bleed valve in where you have the little tee-piece. Reckon it'll work then. I think the blue bit is meant to split the feed for the "twin-turbos" as that's the only difference I can see between that kit (the twin turbo one) and the single turbo one which doesn't have the tee.

[wintertidenz]

I tried that, it caused the boost to keep climbing. Turned it around and it didn't do anything.

Might try it again tomorrow when I have time.

[bradc]

Have you tried the arrow on the T in all 3 different directions?

[wintertidenz]

Not yet.

*edit* ASCII didn't work, see attached pic

Blowing the rest of the ways is fine, there is a ball sitting against the one that you can't blow against easily.

If you block off the top or the one with the arrow pointing out, you can't blow through the other ones.

I hope that explains it

[wintertidenz]

Took out the boost controller this morning and tried blowing into the two barbs on it. Wound fully in (apparently no boost increase) there is nothing coming out, but winding it out gradually makes it easier to blow through.

I have a spare t-join at home - if I remove the one that came with the controller, and plumb this in then connect the boost controller to that, would this work? My guess is that it would slowly bleed pressure off the system, but I don't know if it needs to be plumbed back in so that the car doesn't have a fit.

If I can't get it working right I'll just put the car back to stock and review the piping, I could have possibly messed it up when I reinstalled the fuel pressure and boost solenoids back in and redid all the vac piping.

[Ryan]

Just as an aside to this, when you get it going just make sure that all your boost piping is extra secured to avoid them popping off at inopportune moments

[Davezj]

you have a ball and spring in the T piece and the pressure control is done by the valve.

just connect it up as in the instuction the arrow on the T piece goes towards the wastegate actuator and the valve arrow goes in to the top of the T piece

i will find the instuction and post it up give a few mins............

the arrow on the valve is the other way round on your valve and points towards the T piece.

[wintertidenz]

Ahh, that's the instructions I need - thanks!

Wonder why it wasn't increasing boost properly then... will mess around with it this evening.

[apeman69]

Thanks for posting my fitting instructions pic Davezj (which I thought was crap when I tried to install mine).

Righty-ho, here we go:-
The t-piece with the arrow on it goes in the red-tipped pipe coming off the black plastic inlet elbow near the throttle body. This pipe is marked at it's connection to the black plastic elbow with the letter R inside a circle. The arrow on the t-piece should be pointing away from the red-tipped pipe connection on the inlet elbow so that it, effectively, indicates that flow goes from the inlet end of the pipe down into the dark recesses of the engine. Simply cut the red-tipped pipe and insert the t-piece into this pipe (arrow pointing away from the inlet elbow). You are then teeing into this pipe and the adjuster will then connect to the t-piece.

Nearly done:-
There are two nipples on the adjuster 'box'. Connect the one with the arrow on to the vertical nipple on the t-piece (the nipple on the t-piece that doesn't have the arrow pointing toward or away from it.)
Do not obstruct the other nipple on the adjuster 'box' - it's for breathing. This is the nipple that doesn't have an arrow on it.

Here's one I prepared earlier:-

[wintertidenz]

Okay, so I did have it set up correctly in the first place by the looks of it.

Do you get any initial boost spiking when you put your foot down? I've put my MBC on one click for the moment and it spikes to about 10-12 psi then settles down to 8.

[Subaru ETA]

my turbo smart one is adjusted to about 12 clicks to make 15psi

[apeman69]

Yes, looks like you had it plumbed in correctly.
In your first post you said that adjusting the MBC does nothing. Is this still true?
After installation I found that it was something like 5-10 clicks in one direction before the adjusting mechanism would 'seem' to be affecting boost i.e. before I could start to fine tune it at a click at a time.
I'd be tempted to close it off (or open it up) fully and once you are getting wastegate pressure alone then turn it up the other way a click at a time until you're at about the PSI you're after.
I was getting spikes with it but I disconnected the pressure feed to the boost solenoid (left all the electronics in place) and that improved things.
On the picture I posted this is the pipe with the yellow tube folded over on itself. I read about this somewhere on here and it seemed a good idea at the time, though I can't remember exactly why.
May be worthwhile setting it a bit lower than you want (to protect from potential spikes) and run it for a while in case the spring/ball mechanism needs wearing in a bit. I imagine the spring will become a bit compressed over time and with everything being new it may be an idea. You may then need to set it again.
BTW when I fitted mine I was getting what seemed unlimited boost because the ball inside the t-piece was stuck up with paint!

[wintertidenz]

I haven't had time to play with it yet, will try that in my preferred cul-de-sac area which is nice and quiet.
I can get 7psi no problems, and when I had 3 clicks yesterday I had 10psi... so it might be working - I thought that it might have done that due to the pin-hole in the tee piece... will need to investigate further tonight.

Will isolate the boost solenoid and see if that helps, it's easy enough to get to seeing as it's floating round that area with no bolts holding it in!

I've pulled the tee piece apart (to the detriment of the nice anodised finish!) and checked that there is nothing blocking it up, there were a few metal bits in there so it's just as well that I took it apart.

[wintertidenz]

Okay, adjusting it DOES make a difference - 14psi is fun!

I've plumbed the breather back into the vac pipes before the new t-join, and it lessens the spiking - but it doesn't alter the boost control at all. Will do some more testing however.

[apeman69]

Adjuster will only allow you to alter level of boost if it is connected how you first had it. Connect it like that, set to your desired level then try disconnecting the boost solenoid & see if the spiking lessens.
These MBCs will only work correctly if they're connected how they're supposed to be.

[Davezj]

[QUOTE=apeman69]Thanks for posting my fitting instructions pic Davezj (which I thought was crap when I tried to install mine).

Had the pic on my PC in my boost control section, didn't know where i got it from. i always down load/copy and good pics to my pc as you never know when they will come in handy. beats trawling through loads of threads looking for it.

i didn't get any instructions with mine either.

i have now done a couple of mods on mine and will have to see what happens. i had it connected to a turbo and a couple of gauges in my lounge and had a compressor creating the boost to see how it actually worked, and it didn't seem to give the response i expected, hence the modifying.

only time will tell.

[apeman69]

Dave, I agree with you about the pics and you seriously want to spend some of your spare time actually working on your car instead of your bizarre in-house experiments!!!

[dinger1983]

i have the same one and all the adjustment from standard to 1 bar happens ovr the crest of 1 click its a bloody nightmare

[wintertidenz]

Well, currently with the boost solenoid connected and the vent looped back into the system I get inital spike to about 13psi then it settles down to 9.5-10psi so I'm happy with that. I've wound it out 3 clicks to get 10psi - my one is currently about 1 click per PSI.

I will disconnect the boost solenoid this weekend and route the MBC vent into the low pressure side of the intake - where the boost solenoid vents itself I think? The one that you remove and plug up when you put in an EBC, anyway... I'm a believer that the vac system shouldn't be venting to atmosphere and would rather route it back into stock piping where possible as a safeguard.