# N75 or MBC?



## tt_kcalb_nevar (Feb 26, 2010)

Hi guys, my N75 is starting to go bad and I'm thinking about replacing it with the same oem N75(F) (I checked with APR and they advised to not use any of the different revisions of the N75). I was reading on a couple forums of people bypassing the N75 completely and going with an MBC instead. What do you guys think? 

:beer:


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## Cabbet (Nov 25, 2007)

I'm interested in knowing this as well...my system works great, just curious to know what changing out the solenoid would do.


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## surfinsk8r (Feb 8, 2010)

I don't run an N75, just keep it electronically plugged in.
Benefits:
Control and smoothing of boost spike
On EBC, you can dial in your waste gate spring pressure exactly for even more boost curve control
Quicker Spool
On Non-Bleed Types, boost is either on or off, and therefore is more predictable

Just my .02
:beer:


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## ysmdyb (Jul 6, 2009)

"I don't run an N75, just keep it electronically plugged in.
Benefits:
Control and smoothing of boost spike
On EBC, you can dial in your waste gate spring pressure exactly for even more boost curve control
Quicker Spool
On Non-Bleed Types, boost is either on or off, and therefore is more predictable

Just my .02"



Same setup with MBC :thumbup:


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## bgweed (Jan 18, 2010)

I guess the only thing you would lose is the ability of the ECU to prevent boost. I deleted my N249, so I'm leaving in the N75 for now... that way the ECU has at least one way to run without boost if need be.
Who knows, I may take it out eventually.


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## tt_kcalb_nevar (Feb 26, 2010)

Awesome! That's what I wanted to hear! Doesn't make sense to spend $100+ on a new N75 when I can build a Boost Machine for half that price!

Now, since the N75 is like a T connection with 3 hoses and the MBC (in my case Boost Machine) is only 2 connections, whats suggested to be done with the third hose?


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## ysmdyb (Jul 6, 2009)

You do not need 3rd hose. Sealed up the hose or use vacuum cap :thumbup:


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## tt_kcalb_nevar (Feb 26, 2010)

Great! Thanks!

:beer:


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## surfinsk8r (Feb 8, 2010)

I just hooked up the third hose because my ebc had the port, and came with a cone metal(?) filter that allowed you to vent to atmosphere, so I said f*ck it and recirculated like oem.


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## Doooglasss (Aug 28, 2009)

You cannot seal the third port - that port is used to bleed of boost. If anything have it exposed to atmosphere.

Also you cannot use a ModShack boost machine in place of the N75 - or so I believe.


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## DurTTy (Aug 14, 2007)

DougLoBue said:


> You cannot seal the third port - that port is used to bleed of boost. If anything have it exposed to atmosphere.
> 
> Also you cannot use a ModShack boost machine in place of the N75 - or so I believe.




You can bypass the N75.. its not a problem... just keep it plugged into the harness and hang it up or tie it up somewhere..


the line from the pressure side goes on the inlet side of the MBC and the outlet nipple attaches to the hose that goes to the top of the wastegate... 


any MBC works like this .. regardless of the make or model... 

ALL boost controllers modify the pressure signal from a boost source and then send a "modified" reading to the wastegate so that you can reach and hold the desired boost.

3rd nipple on the n75 goes into the TIP and is not a requirement for anything.


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## tt_kcalb_nevar (Feb 26, 2010)

DurTTy said:


> You can bypass the N75.. its not a problem... just keep it plugged into the harness and hang it up or tie it up somewhere..
> 
> 
> the line from the pressure side goes on the inlet side of the MBC and the outlet nipple attaches to the hose that goes to the top of the wastegate...
> ...


In regards to the third hose, while I'm in there I can just cut it down to an inch long or so and just cap it, I mean if its no longer necessary, right?


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## Doooglasss (Aug 28, 2009)

What I was trying to say is that if you're keeping the N75 and using it as a mbc like it was designed then you cannot block the third port since it's used to bleed boost off. 

The modshack boost machine is a n75 modifier I believe. I have tried to use it without the N75 and I couldn't get it to work right. Maybe you can. 

If you aren't using the n75 then it doesn't matter what you do with all three of the ports. As long as you don't leave a leak in the TIP.


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## DurTTy (Aug 14, 2007)

tt_kcalb_nevar said:


> In regards to the third hose, while I'm in there I can just cut it down to an inch long or so and just cap it, I mean if its no longer necessary, right?


The long nipple which goes to the TIP can just be left alone.. it has no lines going to or from it so it can just vent to atmosphere .. 


my suggestion is to undo the 2 lines on the N75, leave it plugged in and in the TIP and just run the MBC on its own.. 

so the pressure side hose (coming from the turbo) goes in the inlet side of the MBC 

and the oulet side of the MBC goes to the wastegate... all you need is 2 lines... 

the 3rd nipple (which is the long one) -- just pushes right into the TIP..

see the pics below: THIS IS AN OLD SETUP

here is the a diagram of the boost valve system running the n75 in parallel 










HERE IS A PIC OF THE N75 CONNECTED IN PARALLEL TO BOOST MACHINE ---

FOR REFERENCE ONLY, SEE HOW 2 HOSES CONNECT SILVER IS FROM BOOST MACHINE AND BLACK HOSE IS TO THE WASTEGATE 
3RD NIPPLE IS THE ONE THAT PUSHES INTO THE TIP AS YOU CAN SEE IN THE PIC

WHAT I AM SAYING IS DISCONNECT THE BLACK HOSE COMPLETELY RUN THE SILVER HOSE TO TEH WASTEGATE AND THE SILVER HOSE WITH THE BARB CONNECTS TO THE HOSE COMING FROM THE PRESSURE SIDE OF THE TURBO. 










HOPE THAT HELPS


FYI -- ALL MBC/EBC ARE STAND ALONE UNITS... MODSHAK JUST SUGGESTS TO RUN IN PARALLEL IN ORDER TO SIMPLIFY THE INSTALL AND REDUCE FAQS


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## DurTTy (Aug 14, 2007)

The above steps also work for any mbc --- you just unplug the boost source... And plug it to the mbc boost source input..


Then you unplug the modified boost hose (black one in the pic) and then plug that into the mbc output 

and voila.. 


Not much else to it lol

just make sure the n75 is plugged in and leave it in the tip or plug the bung on the tip for the n75...


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## tt_kcalb_nevar (Feb 26, 2010)

DurTTy said:


> The long nipple which goes to the TIP can just be left alone.. it has no lines going to or from it so it can just vent to atmosphere ..
> 
> 
> my suggestion is to undo the 2 lines on the N75, leave it plugged in and in the TIP and just run the MBC on its own..
> ...



That really cleared things up for me! Thanks!!!!!!

:beer::beer::beer::beer::beer:


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## coachvtt (Jan 16, 2008)

*confused!*

Well I have a MBC, TurboXs

I want to delete the N75 and add the MBC, I have deleted the N249.

So If I bybass the N75, but still keep electiacl connected, and the N75 has three ports in a "T"
when looking at the N75, the bottom of th "T" is inserted on the air intake. So the left side of the"T"
is running to what? and the right side of the "T" is running to what?
I mean if I'm holding the n75 which has three ports in the shape of a "T"
Looking at the connections bottom left right ports help me connect!
thanks!


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## ECS Tuning - Audi (Oct 12, 2009)

coachvtt said:


> Well I have a MBC, TurboXs
> 
> I want to delete the N75 and add the MBC, I have deleted the N249.
> 
> ...


The line going into the TIP is not needed in a MBC/N75 delete system. The other two lines go into the MBC.

For those who are intimidated by this mod we have a couple N75 options. A race option which adds a couple pounds of boost through most of the dyno curve, a standard option Revision F - each for ~75 and ~65 respectively. For those interested in a replacement N75 valve - click here - click click.


For those who want to do the bypass or run a parallel boost controller - we've got some great forge options here - click click


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## tt_kcalb_nevar (Feb 26, 2010)

[email protected] said:


> The line going into the TIP is not needed in a MBC/N75 delete system. The other two lines go into the MBC.
> 
> For those who are intimidated by this mod we have a couple N75 options. A race option which adds a couple pounds of boost through most of the dyno curve, a standard option Revision F - each for ~75 and ~65 respectively. For those interested in a replacement N75 valve - click here - click click.
> 
> ...


Hi Chris,

I noticed that the $65 N75 is listed with an MFG# 06A906283E, I checked the N75 on my TT and it has an MFG# 058906283F which your site lists at $104. Im just curious if that $65 item is the proper one to use on our cars? I am a bit of a noob to the VW scene so my apologies in advance if it is interchangeable and I just dont know any better. If it is the proper one, then that's a killer deal! :beer:


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## ECS Tuning - Audi (Oct 12, 2009)

Ha ha, no problem it can get confusing. It is an E revision but it is perfectly usable. So are J revisions (and ECS Race versions if you are not chip tuned).


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## tt_kcalb_nevar (Feb 26, 2010)

Cool, thanks for clarifying!


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## robingohtt (Nov 6, 2005)

nice thread


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## skitzafit (Nov 17, 2008)

[email protected] said:


> The line going into the TIP is not needed in a MBC/N75 delete system. The other two lines go into the MBC.
> 
> For those who are intimidated by this mod we have a couple N75 options. A race option which adds a couple pounds of boost through most of the dyno curve, a standard option Revision F - each for ~75 and ~65 respectively. For those interested in a replacement N75 valve - click here - click click.
> 
> ...


Having used this forge unit with my previous 2871 set up I will say it does its job and nothing more. I did have an issue once with it blowing the crew top off but I am sure that was my fault at some point. That being said I would go EBC any and every day of the week. The amount of control you get especially with duel boost setting and other great features. My advice unhook the N75 but leave it plugged in as mentioned before. Then get a decent EBC and rock out. *I wish I had gone EBC to begin with rather than wasting money on the MBC. Remember the best price may not be the best option*! Again note I don't agree with introducing a product and trying to make a sales pitch in an information thread without giving any actual information.


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