Alright, Greg, I did your MBC test and it passed. It will bleed the air when the boost controller is more plus. When it is in the negative side, it bleeds the air very slowly (Arrow side). Opposite of the arrow side, the MBC blows right through like you described. Now for Rob, so put the MBC close as possible to the arrow side to the wastegate right? And you said tap the MBC in the BOV line somewhere before the head and after the throttlebody. The BOV line is connected to the intake manifold after the throttlebody. It is a bigger port. I disconnected the BOV line and their is a lot of vacuum there. So now, I have no compressor or IC nipple to install the MBC to, the only route I can take is the one in the Vfaq I believe. Rob what do you recommend, I did all your tests, just need to install the MBC.

First, the BOV should "stand alone" with a tap from the intake manifold to the BOV, if you have this, then move on. One line from intake manni "AFTER" the TB is what you want. Sounds like your good here.

Second, the mbc plumbing should be as close to the turbo outlet as possible. ie: the nipple on a stock t25 or the nipple on a 14b j-pipe. They are boost sources as close as possible to the turbo. Why? See Nick Bores explaination a few posts up. Explained brilliantly

What I suggest, is for you to either drill and tap a hole for an NPT nipple on your compressor housing right near the outlet, or drill and tap a hole for the same kind of nipple on your lower IC piping right by the turbo, or have a bung welded on etc........get my point? The boost signal feeding the MBC and WGA should be comming from "AS CLOSE TO THE TURBO AS POSSIBLE. It should also be "STANDING ALONE". By this I mean nothing else tapped into it.

So, for sh*ts and giggles, lets review.

1- BOV has one single line from intake manni to top nipple on BOV

2- A boost source is tapped either on the comp housing or on the IC piping as close to the turbo as possible, going into the inlet of your MBC, then the outlet of the MBC is going straight to the WGA. Keep these vaccume lines short as possible, use high quality silicone, strap them down with zip ties to prevent damage. Should your MBC feed line crack or tear, over boosting is the result.

Wow excellent explanation. Well right now I have to temperarely do it like the Vfaq until I drill a hole in the j-pipe and get a nipple welded in. Prior to this, my MBC was all the way where the BCS was, which makes the wastegate to MBC vac hose pretty long. Maybe I should mount the MBC closer and make that line as short as possible for now.

You've confirmed that your MBC is working properly, and that it is hooked up in a manner that many other people have found controls boost reasonably well.

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Does the BOV piston return quickly after you push it all the way upwards and release? A 3/8" drive ratchet handle works well to move the piston.

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I saw your post on DSM Tuners where your location was given as Scarborough, which is close to where I live, so I could have lent you a hand.

ALright quick question, how big are the vacuum lines suppose to be that connect to the wastegate to the MBC to the BOV line (for now only before I get the nipple welded on). Are they suppose to be the same size as the vac hoses that connect to your throttlebody (boost gauge etc), or they suppose to be the size of the BOV line (which is bigger). I am pretty close to get this damn thing to work.

Get a barbed fitting and have it welded into one of your ic pipes. The jpipe would be a good idea. I had my bov hooked up properly when I was running the smic as my RRE included a nipple but when I switched to a fmic the new jpipe I got didn't have a nipple so I sourced it of the bov. I don't like this setup and will be getting a barb welded in next spring. With the turbo hooked to the bov I get huge boost spikes.

Thanks for the info Daren, I really appreciate it. Everything makes a lot more sense now, so much misinformation out there on this MBC hook up and so far all of you been guiding me towards the solution. Anyway, I am on to this and need this question answered asap. After this I think I figured it out .

ALright quick question, how big are the vacuum lines suppose to be that connect to the wastegate to the MBC to the BOV line (for now only before I get the nipple welded on). Are they suppose to be the same size as the vac hoses that connect to your throttlebody (boost gauge etc), or they suppose to be the size of the BOV line (which is bigger). I am pretty close to get this damn thing to work.

I have used both (well aftermarket silicone) but both diameters and they both seemed to work fine.

Yes, the lines that come stock on DSMs which are found in over 90% of the engine bay are the perfect size for "most" setups because thats the nipple size on the actuator.

Theoreticly, the smaller the line, the better the responce because of the smaller area to fill with pressure, but in reality, you wont notice the difference at all.

You want the vaccume lines to fit perfectly on the nipples. Too big, they slip off and you have to clamp them which can damage them.

Too small and you tear the ends from trying to stretch them over the nipple.

External wastegates such as Tial and Greddy etc....come with larger nipples, and then its a good idea to change your boost source nipple to the proper matching diameter.

Drilling and tapping a 1/8 NPT thread is your best bet when deciding what to do about making your boost source location closer to the turbo. This way, you can simply screw in the same thread with a different diameter nipple for changing diameter of vaccume hose for changes made in your setup at later times. 1/8 NPT will give you a range of sizes of nipples that come with that threaded end.

Alright well, I hooked up the MBC again this time made the lines much shorter which is the proper way of doing it. I get the same stupid thing. If I am WOT and shifting fast, the boost takes forever to build up in each gear. However, if I punch it shift wait a few seconds and punch it again, the boost comes on fast. Another thing I noticed is when I have the boost controller all the way to negative tight, the boost still reads 15 psi and creaps to like 16-17 psi. Hmmmmm.....I don't think if I tap a hole in the j-pipe and screw a nipple their will cure this problem(still going to do it anyway). It will make the boost more responsive but won't cure the huge lag between shifts. I thought when I disconnected the wastegate yes the boost came in fast but I didnt attempt to shift fast and punch it again due to the potiential of the boost going too high. Anyway, I think I plan to put shims on the wastegate actuator, I really don't know what else I can do.

You said you tried unhooking the signal to the waste gate once already. I am "assuming" by your wording in the few posts above you had "NOTHING" on the waste gate?

Did you try just one line to the WGA "WITHOUT" a MBC?

I have tried unhooking it, I tried to plug it to the BCS, and I tried hooking up the MBC the other way around. They were all similar results, unlimited boost. Now the problem is I couldn't test my WOT and shift right after properly because of the potiential of overboosting. The car boosts fine in the gear however, if I am wot and shifting boost takes forever to build in the next gear. If I am wot than shift than wait a few seconds to WOT it again, then the boost comes really fast. It isn't the 1g BOV because I had this problem soon after my 6 bolt swap, I had the 1g bov setup with my 7 bolt. I think after shifts the flapper stays open too long and doesn't shut right away. Now the whole Vfaq MBC hook up precedure have worked for many people. They didn't report any incredible lag between shifts or anything. It might not be good for your turbo but in a way it works right. I am going to do the J-pipe nipple install, however, this problem is really pissing me off now. I feel like just buying a new turbo or MBC lol.

Damn this thread got long, have you tried taking the mbc out and using nothing at all? If its not the mbc problem its probably your actuator.

Well switch the way the mbc is hooked up (source it from ic pipe), which it looks like your going to do. But your problem is looking like the actuator. Try some shims to preload it and/or switch to another known working actuator.

Alright I took off the actuator. It looks mint (Because I bought it new due to my old one being damaged when I got this JDM motor). However, I noticed it doesn't quite line up with the flapper. It is about around half a centimeter off or something like that(When I say off, mean the rod is half a CM on below the flapper where the hole is on the rod. Can I just turn the rod of the actuator to make it line up better? Or can that damage the actuator. I think putting the rod in while being half a CM off maybe is the problem. I can put it back in, but it doesn't like being in that position lol.

Post deleted by Greg Farrell.

Post deleted? lol thats awesome help!!! Just kidding man. Yeah just need to know about the rod if I can twist it a little to make it fit on the flapper better. Read my pose prior to gregs.

How exactly do you mean the hole in the actuator is .5 cm off from the wg flapper? Do you mean its like the wg actuator arm is too short? If so thats ok, you need to pull the wg actuator arm out abit to fit on the flapper, this puts pressure on the wg flapper to help it stay shut & not leak.

The wastegate actuator is long enough, however, it doesn't completely line up when I install it, I have to force it a little to put the WG rod hole in the flapper.

_____
_____ Flapper

0.5 cm different
_____
_____ WG rod

The rod is actually 0.5 cm Below the flapper where the hole lines up with it.

Alright, anyway, time to put shims on it. I will let you guys know. Thanks a lot again guys for the help.

Jesse

Alright put the washers in. It was a pain to pull that rod on the flapper after that. Alright, I did the test run and samething, huge lag between shifts. Alright, I have one more actuator to test out, wish me luck.

I had written up a detailed post explaining how to TEST the actuator by bypassing the MBC, but I deleted it because it was just a rewording of the same thing that other people had suggested earlier.

If I were you, I'd print out this entire thread and highlight the appropriate sections with a pen or highlighter, and make sure I do every test. Or perhaps I'd just admit my limitations and take the car to a mechanic.

No hard feelings, OK dude? I may be buying a DSMlink from you in the summer after all.

You can also do a preliminary test of the BOV by placing your hand on it while you open the throttle quickly. You should feel a click as the piston slams down in the seat. Repeat this test a few times in rapid succession.

At idle there is vacuum keeping up the BOV piston. When you open the throttle, the vacuum goes away and the piston goes down. (And under boost there is pressure keeping the piston down.)

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I bet your actuator is good. I also suspect it's a 15 psi actuator instead of an 11 psi one.

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Did the wastegate flapper move easily when the actuator rod was disconnected?

Alright tried another actuator, same damn ****. However, I noticed my boost wasn't consistant. I had the MBC set all the way to the negative boost side, in 2nd gear, it would hit around 15 psi , 3rd gear it would go to 17 psi, 4th gear almost hit 20 psi (All these boost figures helpd solid to redline except 4th because I let it off when it hit 20 psi, thats too high for me). The MBC isn't doing its job, next thing to do is weld the nipple on the j-pipe and see if that makes a difference and I will do the BOV test. Trust me, I don't have any limitations, mechanics are the stupidest people sometimes, i will never take the car to anyone again. Mechanic spent over 20 hours to diagnosis my cars boost problem (Boost would hit, car wouldn't go anywhere, they tested for boost leaks, smoke test etc, and couldn't still figure it out). Anyway, I took it into the mechanics so I can get the car finished faster, however, after over 20 hours, they couldnt figure it out and guess what, I fixed the car where a mechanic couldn't figure it out. Tomorrow, I am getting the nipple welded and test out the BOV again. Wish me luck and thanks again.

Oh by the way, flapper moves easily when the actuator rod is off.

Is the wastegate flapper arm coming out of the turbine housing? If it is (and i've seen many that are) then it could be hanging up on the inside, causing the delay.

$20 says i could have this sorted out in 30 minutes if i had the car here.

I have another turbine housing I could try out, I have two 14b's, one on my car and the other in pieces (compressor housing off, but compressor and exhaust wheels out and the turbine housing off as well).

by the way, the "shop" I took it to said that my wastegate was fine (Interntional automotive and customs).

Your MBC needs to be open a slight bit to function properly. The way you have it adjusted, no air will bleed through the bleeder hole. The one-way valve inside the MBC will therefore tend to keep the wastegate open.

I'll give you $30 to end this madness.

Well Greg, prior to this 6bolt swap, I've had the MBC all the way to the negative tight and the boost was fine. I have a feeling Nick is on the right track for this one. I noticed this problem was with this 14B in general. I had a T-25 on my 7 bolt boost came on fast and strong no matter how fast I shifted, my 60-1 trim boost came on as fast as the turbo can spin and the lag was the same throughout all the gears evenly. And now, I have this 14B boost comes on strong in the intial WOT then a quick shift to the next gear, it is worse then my 60 trim. Another thing is when I bought this JDM motor from Lucky Star in scarborough, the actuator was bent and had a hole in it. I couldnt tell when I first got it but later on I found out. If it ends up being that flapper being damaged slightly, I am just going to wait and get a EVOIII 16g.

Today I took off my FMIC J-pipe (side to side cooler style) to weld a nipple on it so I can use that source for the MBC. Many people told me that tapping to the BOV line can cause some boost issues that isn't responsive. Earlier in the thread I was talking about how when I shift fast, boost takes forever to hit in the next gear, but when I shift a second slower, the boost seems to come on fast. Anyway, today I noticed 3 out of 4 exhaust manifold bolts that bolt to the turbo hot side housing were loose, two of them were finger loose, I am just wondering could that kill my spool time specially inbetween shifts? I haven't tested the car yet because I am in the middle of welding a nipple on the J-pipe. I am also ordering T-clamps and some better silicone hoses, I was using the cheapy ebay kind, but now I am switching to 4 ply.

All this and you never checked for boost leaks?
Is that right?

Thats not a boost leak, its an exhaust leak.
I remember when a friend at st thomas couldnt boost during a run, we popped the hood and the damn turbo was barely hanging on. No wonder it couldnt build boost.
Yes tighten them up damnit.

Previous shop that worked on my car put on a new compressor housing due to it leaking at 5 psi, I guess they forgot to tightened the bolts. Smoke leak and boost leak has been performed on the car, only thing was leaking slightly was the injector o-rings which I ordered.

Sorry i quickly read what you wrote and misunderstood slightly.

Alright got the nipple put on and did a few runs. I have the MBC slight open a little bit so it can bleed. Anyway, the Boost is very unconsistant. When I punch it, at 4500 RPM its at 10 psi and holds until it hits 5000 RPM then its at 14 psi then by 6500 RPM its around 17 psi. The lag between shifts has decreased with this method I noticed. I have a feeling that this MBC isn't good. IT should hold a steady boost. The MBC is hooked up properly where the arrow goes to the wastegate and the other side to the J-pipe nipple. My A/F is at 10:2 at WOT and get around 15 degrees of timing. I get about 0.4 knock sometimes, not even 1 full degree.

Even the best boost controller won't hold the boost steady if there's certain problems in the system.

You should get 10psi before 4500.

Have you checked yet to see if the wastegate flapper is getting stuck? The short little lever for the wastegate on the turbine housing should be practically touching the housing. If it's sitting away from the housing, and you can see the pivot bushing, then it's slipped out. I've seen it happen quite often and could describe all the problems you're having.

To fix this do you use the side of a hammer or something to put it back into place?

I noticed when moving the flapper it was extremely easy, my other turbo housing, the flapper is actually touching the metal a bit. This is what your talking about right Nick? I am so damn close to this problem lol, just I never experienced this before in my 5 years of owning a DSM.