^ beat you to the punch ;P

I've heard around that venting to the atmosphere is bad and was wondering if what I had is venting. Actually I saw it on the newb Top 10 and I'm pretty sure it was number 1 . Purchased the car about a month ago and this is pretty much how I got it. Couldn't get much info on mods on the car because the father was selling his son's car who was not there and the father didn't speak much english. Just drove it and fell in love . It's been like this for a while but I've never noticed anything like stalling or bad idle problems which I think are the main problems for venting. Not sure if I have a link or anything either I have no idea how to check. I'm a noob

BTW since we're getting a bit off topic, would it be safe to tighten the screw on the MBC and see if it's working by checking if boost increases? And how could I check if the boost has increased, unless I have to make a run down my road each time I tighten it

If you smell gas in your exhaust, it means your running rich, due to the blow off valve blowing out air in the intake system, and the ecu thinks it has more air than what it really does so it floods the system with gas, also, so far as tightening the MBC, that would restrict boost, if it's tightened all the way, it makes the turbo only spool to stock boost, the looser, the more boost you're running.

Link is not the answer for venting to the atmosphere. A gm maf plus translator is or a speed density setup.

Oops my bad, that's what I meant, also a MAP would suffice

Oh wow I've been tightening it bit by bit each time I stopped to at a parking lot and decided that it wasn't working because the boost stayed the same . Guess I'll try again. Also is it safe to loosen/tighten the screw while the car is on? I've been doing it while the car is off just to be safe but it's a hassle.

I don't think I smell any gas from the exhaust, is there any other way to check if I need to recirculate the BOV or is it I MUST recirculate it. Thanks guys!

Thats the Turbo XS RFL bov, I have one, it's not possible to recirc this bov, but it's never been a problem for me.

How can you not follow the vacuum line from the wastegate? Where do you lose them, do they go back towards the cab?

Yes, your BOV is vented. That RFL is not designed to be recirculated.
Recirculated blow off valves have a tube connecting them to the intake pipe, like so:

Bojangles465 said:

Oops my bad, that's what I meant, also a MAP would suffice

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If you are saying a MAP sensor will allow you to vent your BOV, you are incorrect. While a MAP sensor is part of what you need to make speed density work, a MAP sensor in itself will only measure manifold pressure. The ability to properly vent a BOV is determined by how your air meterting system is setup, whether that be a GM MAF in blow through or speed density. The reason it is frowned upon in the stock configuration is that the MAF is before the blow off valve in the system. It has already measured the air going into your engine and if you are venting it is escaping the closed system, thus making the reading your MAF already made incorrect. With a GM MAF in blow-through the MAF is after the BOV, so even if you are venting air off it measures it after the fact and so it doesn't matter if the air leaves the system or not. Where as speed density actually calculates the air in the system based on air temperature and pressure in the manifold, also making it so venting is acceptable.

Oh ok so I would just leave the BOV alone? It hasn't given me any problems anyways, just wanted to make sure. And yeah it looked weird because where the recirculated tube would go, the hole is like going outwards so it doesn't look like a tube would fit on properly.

I tried following the line from the wastegate but it looked like it went back to the intake right before the turbo? Or I might be looking at the wrong thing. It was the line that was attached to the boost controller under my seat that I lost, it went under the carpet and under my seat so I couldn't follow it. But after seeing that I did a more keen inspection and found this. Now I'm really getting confused.

BTW it was under the cup holder, it was there the whole time but I never thought of moving the cup holder before. Also its pretty stuck, not sure if there are lines attached to it but I couldn't get it out.

Dude you've found his stash . It's looking like he tried rigging a dual stage setup but the reasoning behind the way things are makes no sense.

Oh and you said you're a noob so... You know where the waste gate is located and what it looks like right?

I always take my cars apart after purchase. It allows you to find sweet stuff like money! Or even better, hack jobs with two MBC's

Lol if I took apart my car I'd never be able to put back together.

And yeah I think i have a general idea of what the wastegate is. It would be the gold/bronzeish school bell looking thing with the long stick that actually opens the real wastegate? So that would be the wastegate actuator I guess, I think .

Ok so I'm assuming that both of the MBC's I found are not working because I was trying to adjust boost but there was absolutely no effect.

Now I'm trying to install a new NXS MBC but I'm having a lot more trouble than I should be. I've read I feel like literally ALL threads about installing a MBC and I feel so dumb but I still can't figure out how to install it. I know it's the vertical side to the boost source and the other side to the wastegate actuator. The part I'm having the most problems with is finding out where exactly the boost source is on the turbo. I've seen the diagrams but I can't pinpoint it exactly on my turbo.

What I think I need most is an actual photo of a MBC installed on the stock turbo and intake and wastegate actuator. I need to see where the lines go EXACTLY. I know where one of the lines go, the one to the wastegate actuator I'll put a pic to show you to make sure.

Also what steps are needed prior to the actual installation process. For example, do I have to remove the intake to get the space to get where I need to install the lines? Also do I need to buy my own vacuum lines, some people say I do and I've seen other threads saying that you just steal the ones from the BCS or something like that. I don't even know where the BCS -.-

Any help would be appreciated, it's beyond frustrating when something so simple can't be done.

my mbc is right off the wastegate/j pipe nipple stock 14b turbo. I'm about to go to the garage to work on my car. I will take a picture of my MBC hooked up.

Alright sweet, thanks man. Yeah I honestly don't know where the j-pipe or nipple is in real life . I couldn't compare the diagrams to my turbo.

Is yours stock t25 turbo?

Yup.

Here is the pic, the j pipe connected to the MBC then connected to the waste gate actuator on turbo.

Oh man thanks a lot, I saw that pipe and was wondering if it was the J-pipe. So the picture I took of the wastegate actuator is correct when I have to install a vacuum line there?

Also do you have to get under your car to be able to install it? And did you have to get your own vacuum line or do you re use the lines that are there?

Can you get a picture of the vacuum lines on your turbo/ pipe that comes off the cold inlet to see if its a nipple there.

Sorry I'm not sure exactly what you're talking about. I'll just try taking pictures of the turbo area from all angles I can coming from the front of the car .

You don't have a J-pipe. You have a t-25, your boost source is right here, under the intake pipe.



Install your MBC between that nipple and the wastegate actuator.

don't mind the artwork much, just a pro @ work.

gsxtasy said:

You don't have a J-pipe. You have a t-25, your boost source is right here, under the intake pipe.

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Install your MBC between that nipple and the wastegate actuator.

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Alright thanks guys! Gonna try getting this bastard installed! The last questions I have are:

Do I need to get my own vacuum lines?

Also what do I do with the line connected to the wastegate actuator right now, not even sure where it leads it looked like it went right behind the intake/turbo, if you can see what I mean by the picture I posted.

And I remember something about the Boost Control Solenoid where I'm pretty much replacing it. Is it anything I have to worry about? Also can I do this easily looking from the top of the engine bay?

Sorry making this more complicated than it should be .

(Don't worry that's some good painting )

T25 is good for 18psi but its pretty maxed out right there . Doesnt last over 5k. If you hooked your actuator straight to the turbo nipple you would see a stock wastegate pressure of 15psi.