Fitting a manual boost controller ?

[gregorcupra]

Hi there,

Just got my forge mbc this morning and I'd like to know the best way of fitting it as they give no instructions ?

Do I remove the pipework from the n75 or do I use it in conjunction with the boost controller ?

What pipes do I plumb each part of the controller in to ?

Thanks
Gregor

 

[tarzan]

i have a hallman boost controller on my car on line from the boostpipe to controller and from the controller to wastegate. and have the n75 eletric conected

 

[ibizacupra]

if using a forge unos, boost in goes into the bottom and the feed to the actuator goes out of the side exit.

 

[gregorcupra]

Thanks guys,

I found this diagram on the internet and copied what I saw :

Thats it fitted now anyway , and Ive mounted the controller inside the car rather than outside. Hopefully I can turn the boost down a bit to overcome the overboost problem I have been having !

Thanks again

 

[gregorcupra]

Ok all plumbed in so took the car for a spin.

The main thing I have noticed is that the boost controller has a very small hole on it which is obviously put there when its made , but this thing hisses like crazy when the car comes on boost ? Is that normal ?

Also , I started the boost controller on no boost , yet the car would still boost to around 12 psi (normally 18-20) and then after a while it just stuck between 8 and 10.

Where am I going wrong ?

 

[tarzan]

Thanks guys,

I found this diagram on the internet and copied what I saw :

Thats it fitted now anyway , and Ive mounted the controller inside the car rather than outside. Hopefully I can turn the boost down a bit to overcome the overboost problem I have been having !

Thanks again

don`t think you should have the unos inside the carthink it is a controller to have in the engine room.if you want to adjust boost from inside the car.to my controller you can bay a second part to fit so you can adjust from the inside as you can see here
http://hallmanboostcontroller.com/applic.html
i don`t have n75 valve connected like that

 

[tarzan]

Ok all plumbed in so took the car for a spin.

The main thing I have noticed is that the boost controller has a very small hole on it which is obviously put there when its made , but this thing hisses like crazy when the car comes on boost ? Is that normal ?

Also , I started the boost controller on no boost , yet the car would still boost to around 12 psi (normally 18-20) and then after a while it just stuck between 8 and 10.

Where am I going wrong ?

the hissing i air comeing out of the controler. like the n75 this is the 3rd port for ambient pressure
this is how my boostcontroler is connected

 

[M1KEH]

Ok all plumbed in so took the car for a spin.

The main thing I have noticed is that the boost controller has a very small hole on it which is obviously put there when its made , but this thing hisses like crazy when the car comes on boost ? Is that normal ?

Also , I started the boost controller on no boost , yet the car would still boost to around 12 psi (normally 18-20) and then after a while it just stuck between 8 and 10.

Where am I going wrong ?

With the n75 connected still it will still allow some boost even with the boost valve on no boost. Hissing is due to it letting out air to make no boost.

 

[gregorcupra]

Thanks very much Tarzan for your help.

I think I will keep the n75 connected for now as I would think it would be dangerous otherwise if i were to put boost up too much.

I think I am right in saying that if the n75 is connected then I can only turn boost up to the level the car is asking for ?

 

[tarzan]

Thanks very much Tarzan for your help.

I think I will keep the n75 connected for now as I would think it would be dangerous otherwise if i were to put boost up too much.

I think I am right in saying that if the n75 is connected then I can only turn boost up to the level the car is asking for ?

your ecu i programed to a boost level and if you go over that the car hit limp mode.my n75 is only eletric connected no hoses on it.mine boost controller is open max and then i get 1.45bar on my revco stage 2 if i want i turn down to only 0,4bar when fulyl closed.if you can get someone with vag-com you should log block 115

 

[tommy2008cupra]

tarzan do you find the boost smoother with mbc?

 

[wild willy]

The way you have connected your mbc is to smooth out boost spikes only. You will never flow more than you did before you fitted the mbc since the n75 is still controlling the boost via the ecu. All you can do with this configuration is reduce normal boost levels.

If you want to run increased boost (more than normal) you unplumb the n75 but leave it electrically connected. Blank off the hose that goes to the TIP and connect the mbc to the two remaining pipes. Adjusting the mbc will increase and decrease boost accordingly. Be vary carefull not to increase boost too much without adjusting fueling as running lean can be dangerous.

 

[gregorcupra]

Cheers for the advice.

So am I better runing the mbc without the n75 , or with the n75 ?

Im just worried that if the N75 isnt plumbed in but is electrically connected then it will throw faults/still cause limp mode ?

 

[gezmeister]

Keep the n75 plugged in, but not connected to any hoses. As long as you don't turn the boost up a huge amount, it shouldn't cause limp mode

 

[tarzan]

tarzan do you find the boost smoother with mbc?

smoother and holds boost better before i had peak here and peak therenow i got 1.45bar i 3gear.tried with n75 got 1.1 other time 1.2 and sometimes 1,6 now i hit 1.45 bar thats it if you search for the forge unos on here you will find out a lot more i have the hallman boost controller from usa

 

[tarzan]

The way you have connected your mbc is to smooth out boost spikes only. You will never flow more than you did before you fitted the mbc since the n75 is still controlling the boost via the ecu. All you can do with this configuration is reduce normal boost levels.

If you want to run increased boost (more than normal) you unplumb the n75 but leave it electrically connected. Blank off the hose that goes to the TIP and connect the mbc to the two remaining pipes. Adjusting the mbc will increase and decrease boost accordingly. Be vary carefull not to increase boost too much without adjusting fueling as running lean can be dangerous.

if you got more boost then what ecu request you will hit limp mode.on my other map i got limp mode at 0.9 bar with the boost controller so turned it down to 0,85 no problems. i got 158gs on maf with 0.85bar just whaiting to see what my new revo stage 2 will give just snow and ice so have just taken some logs yet and looks find but need more good log runs to see mine stage 2 i b8t8 waitng for my sps3 to come in the mail

 

[wild willy]

if you got more boost then what ecu request you will hit limp mode.on my other map i got limp mode at 0.9 bar with the boost controller so turned it down to 0,85 no problems. i got 158gs on maf with 0.85bar just whaiting to see what my new revo stage 2 will give just snow and ice so have just taken some logs yet and looks find but need more good log runs to see mine stage 2 i b8t8 waitng for my sps3 to come in the mail

Not necessarily it depends upon what boost deviation limits have been programmed into the ecu. The minimum i think is 200mb. So if your currently holding 0.9 bar to the red line a mbc could allow you to reach 1.1bar at red line provided that he turbo is capable of flowing it in the first place and other parameters such as fueling have been adjusted to suit. Sometimes the engine management light will come on if more airflow than what the ecu is mapped for is seen by the maff due to increase boost at the redline. Suck it and see. An email to your remapper should answer most of these concerns.

 

[gregorcupra]

Right, still have the mbc connected with the n75, but still I have a problem!!

Even though I have turned the boost down to 15 psi , it will still go into ****ing limp mode

Take for example tonight. I ran some friends into town just cruising in 5th gear. Cruised most of the way home but thought while I was on the motorway I would see how the car would go if I dropped to third. So down to third , accelerate and then limp mode.

The most annoying thing is that the problem is completely intermittent.

Could I be looking at a dodgy n75 valve ? Im going to run the mbc on its own without the n75 to see if there is any improvement

 

[gregorcupra]

Should have also mentioned that the error im getting is 17965 - overboost.

How can it overboost if ive turned boost down !?

 

[tarzan]

boost leak maybe i just have the n75 eletric connected with no hoses.and have no problems with this fault code.had the same fault code on my previous map but turned boost down a little bit and deleted the fault code and diden`t come back