What vaccum lines run to turbo outlet?

[htown240]

Hi, I was just wondering if anything that deals with vaccum should be attatched to the turbo outlet. There is a threaded plug in there right now but I was going to put in a 90 degree elbow so there is an outlet and was wondering what items should be hooked up to this or if all my items should be hooked up to this. Need to know for my wastegate, bov, boost gauge, fmu, ect. Any knowledge or experience would be helpful. Thanks!

[candela]

do not use that for anything...

Use the BOV, FPR, wastegate and anything else from the intake manifold itself. You will get a much better signal, more controllable boost (mbc), more accurate everything. Keep it plugged, trust me

[IvanAtSPRacing]

The outlet on the compressor housing will only provide one good reference signal. This would be boost (no vacuum). There arent many thing that ONLY boost is good for. Usually the only thing that is run off this port would be the boost controler. This would be hooked up to the IN side of a MBC or electronic boost controler. NOTE, most electronic boost controlers also need to see manifold vacuum (from the intake manifold) at either the boost control solenoid or the head unit. Follow the manufacturers instructions.

[candela]

The ONLY thing that that as been used for from any turbo manufacturer and from actual factory equipped cars is for the wastegate. Vacuum is NOT NEEDED for a mbc you are right but it sure does help seat the ball (ball/spring types) in a MBC.

This port is really NOT a good source for boost at all. Go from teh intake manifold period. That is the most accurate source for boost signals to ANYTHING because that is what the motor actually sees. readings from the outlet of the compressor housing are not even accurate anyway.

[IvanAtSPRacing]

do not use that for anything...

Use the BOV, FPR, wastegate and anything else from the intake manifold itself. You will get a much better signal, more controllable boost (mbc), more accurate everything. Keep it plugged, trust me

This might not be always true. Vac lines to the boost controler should be as short as possible so the boost controler will react as quick as possible. The signal you get from the compressor housing will be higher then what you will see at the intake manifold due to pressure drop through the IC and piping. You will also see a lag the signal to the intake manifold.

[candela]

You are correct abotu the pressure drop thing but that does not matter. The lines SHOULD be as short as possible you are right, this will help prevent boost spikes and control teh level better overall. But why does it need to go from teh compressor housing (and why didnt you say that in the first post?) for short lines? Can it not go directly from the intake manifold and have short lines?

You will get a much better reading from teh intake manifold I guarantee. Try to hook up boost gauge to the comp housing and one to the intake manifold and see for yourself.

[IvanAtSPRacing]

The ONLY thing that that as been used for from any turbo manufacturer and from actual factory equipped cars is for the wastegate. Vacuum is NOT NEEDED for a mbc you are right but it sure does help seat the ball (ball/spring types) in a MBC.

This port is really NOT a good source for boost at all. Go from teh intake manifold period. That is the most accurate source for boost signals to ANYTHING because that is what the motor actually sees. readings from the outlet of the compressor housing are not even accurate anyway.

I am trying to think of a factory vehicle that doesnt use the compressor housing as the source for the boost controler. I cant think of any.

A boost controler works on differential pressure so it wont matter what you feed it, it will always work. Keeping the lines as short as possible is the best way to keep boost under control. Normally the shortest lines will be from compressor housing to BC to WG

[IvanAtSPRacing]

You are correct abotu the pressure drop thing but that does not matter. The lines SHOULD be as short as possible you are right, this will help prevent boost spikes and control teh level better overall. But why does it need to go from teh compressor housing (and why didnt you say that in the first post?) for short lines? Can it not go directly from the intake manifold and have short lines?

You will get a much better reading from teh intake manifold I guarantee. Try to hook up boost gauge to the comp housing and one to the intake manifold and see for yourself.

Honestly it doesnt NEED to go to the compressor housing. Its usually easier and works better then going to the manifold. You can still have short lines from the intake to BC to WG but that usually isnt the case unless exhaust and intake are on the same side of the motor. The delay in signal getting to the BC is why you go to the compressor housing.

I am sorry I didnt go into too much detail in the first post. The original question from a NEWBIE about something that is probably very elementary to most people here probably didnt warrant a detailed explination. I simply explained what gets hooked up to that port and a not too detailed description as to why.

You will not get a much better reading in EITHER the manifold or the compressor. You will get DIFFERENT readings. The one in the manifold will be delayed and dampened and lower then what you get at the compressor housing.

There are other things you could hook up to a port in the compressor housing like a pop off valve, FMU (although it would be better off the intake), a boost "only" gauge (again better in the intake), etc.

Anyway you look at it, a BC will work off EITHER.

[candela]

I agree...

I just think (from many-a-turbo settups) that that lower, dampened...etc reading is the closest to what the motor sees, thus is the best. A BOV, wastegate and FPR will ALL benefit from running off teh intake manifold, however the boost controllercan easily be mounted there and often is simply because it has to T into the wastegate signal and the wastegate is usually close to the turbo.

If I came off as a **** (just in case) then I'm sorry. I think people always have different opinions and its nice to have peopel shout out without getting silly. Keep boostin ivan!

[htown240]

Wow thanks for all the reply's that I got on this post. I'm just going to go off of the manifold so I can see and the sensors see what the "motor" is seeing. I almost had a tear in my eye when i was called a NEWBIE. I know lots about cars, engines, and set ups, I just wanted to verify what I know and what you EXPERIENCED people know. Love the boards and searching saved my life! Also wanted to know if you guys just t'd off the brake booster line in the back of the engine compartment for the components.

[IvanAtSPRacing]

No problem. I am sorry if you were offended by being called a NEWBIE but with three posts and the basic question led me to believe that. Its good that you check things out before stepping blindly into performance mods. Feel free to ask. This is the place to do it. There are a lot of experienced people here to help you. Be carefull though. The internet is NOT filled with truth. Do some research yourself, go to your local shop and see if you can hang out and maybe learn a thing or two. Lurk around the board and see who is answering questions. You will find out a lot just by listening. Check out the instructions on your BC and see what the manufacturer has to say about hooking it up. Good luck with your car.

[htown240]

Hey 1 more question, did you guys just T off your brake booster line or fpr for your vacuum line dependent items?

[andrave]

I am using a dist. block off the intake manifold for all of themj Z can make you a nice polished one or you can get your hands on the 4 into 1 splitter from the bottom of a ka...

[Nathan]

One other thing to consider is that if your wastegate reference is from your intake manifold and your throttle is only partly open or closed and you are providing enough exhaust gasses to spool whatever turbo you are using, then it will boost, inaccurately since it wont know not to, since it only uses a boost signal, not a vacuum signal. Its kinda a confusing thing to explain but maybe you understand what I'm saying. It also probably wouldn't be a big problem if you were using an appropriately or larger sized turbo, but I could see it possibly happening if you used something with a small turbine housing.

[huguetpj]

I just think (from many-a-turbo settups) that that lower, dampened...etc reading is the closest to what the motor sees, thus is the best. A BOV, wastegate and FPR will ALL benefit from running off teh intake manifold, however the boost controllercan easily be mounted there and often is simply because it has to T into the wastegate signal and the wastegate is usually close to the turbo.

IMO you are wrong. Yes the mani boost is what the motor sees, and yes this is the best signal to read... but definetely not the best control signal. The BOV and FPR NEED to be connected to the manifold cause they need vacuum. A boost gauge also. Any other electronics that read boost, also. An electronic (or manual?) boost controller's read signal should be taken from the manifold... but the control signal, the signal the goes to the solenoid (or valve) and then opens the wastegate would be best be taken as close to the compressor as possible.

Overboost, as we all know, is not good. A bend, leak or cut on the signal line is very bad. I myself have a 90° elbow coming from the compressor outlet port connected to a stainless steel line that goes directly to the the side port of my 35mm Tial. This way I can rest assure the WG will get a signal and open up. As a side benefit when my SBC tells the WG to open it opens up rather quickly.

My BLITZ SBC uses the top wastegate port to handle the Tial. And instructions said to take this signal as close to the TB as possible. I think this is as a precaution. If something goes wrong, like blowing a ic line, then the pressure near the TB dissapears and the wastegate opens up since the pressure differential between the side and top port will be higher than the spring's PSI. But this also may bring me some issues later on when I up the boost, if my pressure drop in the IC route is above 4-4.5PSI.

Just more food for thought.

[candela]

You make perfect sense but nothing you said interfers with what I said :p You say Im wrong but you typed teh same babble that I did yesterday...

Electronic boost controllers are different, and in my un-edited post you will see that I speciafically referred to an MBC (ball/spring) in which case vacumm definetly helps control them. I have used a Blitz SBC, Greddy Profec B, TXS 2 stage, hallman and Joe P... I used the hallman and Joe P from the manifold and had better boost control when compared to compared to running off of the comp outlet.

There are MANY ways to insure you are using a good line and make it very hard to be cut, kinked...etc EBC/SBC will usually have a quicker effect than an MBC period. Boost travels very very quickly my friend and I just say to run that kind of stuff off the manifold (from a block like andrave suggested) because having your wastegate open at a specified PSI and getting its signal from the comp housing and having a boost gauge tapped from the intake manifold... you will be getting different readings. Your wastegate will be opening at a different time and reading than what your gauge says, so unless you tap your gauge into that like as well (which makes NO sense) then you don't even know exactly what boost you are running (or as close to it as possible).....

[huguetpj]

You make perfect sense but nothing you said interfers with what I said :p You say Im wrong but you typed teh same babble that I did yesterday...

Maybe u r wrong is a bit blunt . You are right except for the wastegate open signal.

Quote » Electronic boost controllers are different, and in my un-edited post you will see that I speciafically referred to an MBC (ball/spring) in which case vacumm definetly helps control them. I have used a Blitz SBC, Greddy Profec B, TXS 2 stage, hallman and Joe P... I used the hallman and Joe P from the manifold and had better boost control when compared to compared to running off of the comp outlet. [/quote]

What do you mean by better boost control?

Quote »this will help prevent boost spikes and control teh level better overall.[/quote]

Hmmm. I see. Don't really know how reading from the manifold would prevent spikes and maintain PSI level better. It would just make you boost a bit more.

Quote » There are MANY ways to insure you are using a good line and make it very hard to be cut, kinked...etc[/quote]

Yes there are. I just wanted to play it as safe as possible. My line is like a foot long at most and thus reduces the possibilities of something going wrong.

Quote » Boost travels very very quickly my friend and I just say to run that kind of stuff off the manifold (from a block like andrave suggested) because having your wastegate open at a specified PSI and getting its signal from the comp housing and having a boost gauge tapped from the intake manifold... you will be getting different readings. Your wastegate will be opening at a different time and reading than what your gauge says,[/quote]

No... the wastegate will just open when it does (don't know what you mean by diff time)... at the PSI shown by the boost gauge. Maybe the wastegate is seeing a bit more PSI than the gauge is reading... but does that really matter? IMO no, you're just running whatever boost your gauge says. It doesn't matter what PSI you have at the comp outlet, or hot pipe for that matter (unless you wanna know your pressure drop).

Quote » so unless you tap your gauge into that like as well (which makes NO sense) then you don't even know exactly what boost you are running (or as close to it as possible)..... [/quote]Yes that makes no sense :pface