MBC install [Merged 10-7]

[b00sted99-X]

HERE, DAMMIT!

http://www.dsmtuners.com/forums/showthread.php?t=237982


ok n00b question here.. i got my MBC all hooked up fine (dejon tool.. sweet!) i'm just wondering what to do with the stock boost solenoid hoses.. i took the top one completely off (this is the one that was going to my intake pipe.. then capped that nipple on the pipe) .. the one on the bottom, that tees off and goes to both the wastegate and the turbo housing, is still there. i just bent it backwards and stuck it in the bracket that the top hose was at.. its still connected to the solenoid though. is this alright? can i leave it on there like that will it screw anything up?

 

[skinnykenny84]

for one thing you dont want your mbc so far away from the turbo. it should look just like the pics at the bottom of the vfaq you were reading.

your right so far on tapping in on the bov line, the other side of the boost controller goes (in your case) the nipple on your j-pipe.

 

[skinnykenny84]

You want to keep these lines as short as possible, use a tie down and anchor it to your fan like the one in the vfaq pic. That will be more or less a "middle" between the 2 sourcess.

 

[rjennings]

Hook up the boost controller to the Compressor Housing/Pipe. Then attach the other line to the Waste Gate Actuator/External Waste Gate. T off the BOV line has low pressure source.

I recommend mounting the MBC between the pressure source (compressor housing) and the waste gate.

To avoid hoses spliting/cracking only use Silicon hoses. The MBC should be adequately shielded from heat and at least 100mm from the turbine housing or the exhaust manifold.

Randy

 

[tyger1]

well right now the way it is mounted is right near the battery due to me having to route the cockpit controller cable. see this is where i am confused. one tells me i have it right. and the other tells me to connect the mbc to the compressor outlet nipple. which is correct.? if both are then which is better? thanks

 

[MrBoxx]

Connect the inlet vacuum hose of the MBC to the compressor housing/LICP nipple. Do NOT tee into the BOV line for an MBC boost source. The BOV operates on the principle that a vacuum signal will cause the BOV to open. In the case of a bleed-type MBC, you're essentially creating a vacuum leak in the MBC, causing the BOV to open prematurely.

By using the compressor housing/LICP, you keep the vacuum hoses short, which increases boost response time.

Taking the pressure source from the j-pipe fitting has many benefits.

1. The main reason why alot of mbc instructions and some tech articles suggests to tap from the BOV line is because it's connected to the intake manifold, the argument is that this is more accurate because it's the same pressure the engine sees. In reality this is a non issue because the boost gauge is tap to the intake manifold no matter where you tap your mbc so there is no advantage in tapping the bov/manifold pressure as previously thought.

2. The proper functioning (opening and closing) of the bov depends greatly on the accuracy of the pressure in the vacuum hose you're thinking of tapping on or off boost so it's best to leave it connected directly to the manifold without any interference.

3. Tapping off the compressor/j-pipe offers the shortest vacuum hose route which greatly reduces the chance of boost spike.

4. In the case of boost leaks, tapping off the compressor/j-pipe will help prevent over boosting the turbo.

5. Hooking up a bleeder type mbc like the TurboXS standard mbc to the bov line will result in a vacuum leak as well as affect the working of the BOV.

-as originally posted by oldman

In other words, there are NO disadvantages to using the compressor housing/LICP nipple as a boost source. There ARE disadvantages to using the BOV line for a boost source.

 

[FORMONTOYA]

MrBoxx has my vote as to the correct way to hook up a MBC.

You can just see mine to the left of the upper radiator hose.

 

[skinnykenny84]

I just know that I hooked mine up just like the vfaq (and everybody else I know) and it has always worked fine. Diff strokes for diff folks I guess.

 

[MrBoxx]

It's one of those things like venting your BOV. Some people do it and say they have no ill effects. Some people do it and their car runs horribly. Then, when they go back to reciruculating, all their problems miraculously disappear.

The same way, some people tee the BOV line and seem to have no problems. Then others tee the BOV line and have horrible boost spike, overrun their turbo, get unreliable boost, etc. Then they switch to taking the boost source from the compressor housing, and poof... no more problems.

There's also the belief that taking the boost source from the compressor housing will cause the boost to vary by the weather or atmospheric conditions. Well, I've had mine tapped from the compressor/LICP for three years through Michigan's cold winters and hot summers and have never had my boost be anything but what I set it at.

I just think that, for the reasons stated best by oldman, it's best to take the boost source from the compressor housing or the LICP nipple.

 

[oldman]

you need to block off what ever hose you dissconnected from the intake with a screw or something. you should tee one side to the bov line and the other goes to the compressor (or existing tee shown in picture)

I think you meant the actuator, I hope.

I just know that I hooked mine up just like the vfaq (and everybody else I know) and it has always worked fine. Diff strokes for diff folks I guess.

It's not a matter of preference, Eric has lay out the cons of using the BOV line, there are tests that you can easily do to verify the BOV line is not to be touched if you're interested.

well right now the way it is mounted is right near the battery due to me having to route the cockpit controller cable. see this is where i am confused. one tells me i have it right. and the other tells me to connect the mbc to the compressor outlet nipple. which is correct.? if both are then which is better? thanks

Mr. BOXX is correct, use the compressor fitting. I also have the same MBC, route the line from under the driver dash, wraps aroud the driverside engine bay and mounted on the passinger side radiator fan mount, perfect length.

 

[nightracer91]

Alright, I just picked up a boost gauge and manual boost controller. I got a vacuum diagram from SlowBoy on how to install it. Now, do I have to short out the connector for the BCS or can I leave it unattached and not have to worry about a MIL glaring at me.

 

[ericmetcalf11]

You can just leave the BCS unconnected. I believe you only get a CEL on the 2g's.

 

[jibberishballr]

You can just leave the BCS unconnected. I believe you only get a CEL on the 2g's.

If u just cap it by using a piece of hose and a screw you wont run into any CEL's.

 

[nightracer91]

Ok, so should I cap off the BCS or disconnect it.

 

[ericmetcalf11]

Disconnected it, it's fine. Mine just dangles in the engine bay and I have no CEL.

 

[matt j]

i have mine completely out, it is now sitting in the "misc dsm shit i dont need" box. so just remove it and plug in the boost controller.

 

[nightracer91]

Alright guys, thanx.

 

[jibberishballr]

If you get a CEL youll know its that so you can try just disconnecting it. Good luck!

 

[MrBoxx]

Alright, I just picked up a boost gauge and manual boost controller. I got a vacuum diagram from SlowBoy on how to install it. Now, do I have to short out the connector for the BCS or can I leave it unattached and not have to worry about a MIL glaring at me.

Does SBR's diagram include tapping the BOV line for a pressure source for the MBC?

If so, don't follow it. Use the nipple coming off the 14b's (if you still have it) elbow/J-pipe for a pressure source. There are many reasons not to tap the BOV line, mostly having to do with retaining the reliable and timely functioning of the BOV and giving the MBC a true pressure reading from the turbo, not one that comes after pressure drops and boost leaks. There are no advantages to tapping the BOV line, but there are several disadvantes to doing so.

 

[B0OST]

I do agree with Boxxx, i ran into that problem myself, it was very unreliable, and boost had problems. I have heard of some turbo pipes that come with special nipples for boost gauges and controllers, thinking of trying it out.

 

[MrBoxx]

RRE's J-pipe/L-pipe combo include a nipple on the L-pipe specifically for boost controllers. Several other vendors' pipe sets include fittings at some point between the turbo compressor and intercooler for MBCs.

 

[brute]

I agree with MrBoxx also. I drew up a little diagram in paint.

You must be logged in to view this image or video.

 

[oldman]

That's pretty good actually. I too agree with the wiseman, do not follow SBR's direction or any directions in tapping the BOV line.

 

[joe]

nice

 

[joe]

Should I do the same with a t25? i have it tapped to the bov line right now.

 

[oldman]

Should I do the same with a t25? i have it tapped to the bov line right now.

The BOV line should not be touched regardless, for the sake of precise boost controlling as well as proper functioning of the BOV.