View Full Version : Hallman MBC questions

11-15-2009, 01:43 PM
Hey all,

i am having issues with having the MBC installed only. have the n75 completely unplug (tubing) and hav the electrical connection still plugged in. the isues is i have the controller all the way "out" and the boost is still pushing 2.5 bar.... my gauge only goes to 20 psi, and it goes WAY past it. per VAGcom, the actual boost is 2540mbar, when it requests 1770mbar.

i dont understand what to do? any thoughts?

i will upload a little log, but dont want to do a full run with the boost going that high.

On a side note, i did fix my MAF sensor plug that has been haunting me, so this all is on the same day.

anything anyone can advise with, i would appreciate it greatly. logs or settings; please let me know.

11-15-2009, 01:57 PM
Dial the mbc down.

11-15-2009, 01:58 PM
it is all the way down. thats the issue...

11-15-2009, 01:59 PM
I would make sure that none of the lines coming to and from wastegate and boost controller are kinked. I would also check and make sure the wastegate is functioning properly. It sounds like your WG is sticking causing you to spike real high.

11-15-2009, 02:05 PM
^^ thanks for the input guys. I will double check the WG functionality and also double check the lines to and from.

i will keep you all posted.

11-16-2009, 09:58 AM
checked the hoses and WG. does not appeasr to be stuck open or closed. all lines are kinkfree..

any other thoughts????

please help. i hit well over 25psi... i get surging at those levels. have the mbc all the way counterclockwose (lowest setting) and still hitting massive boost.

11-16-2009, 10:04 AM
How did it react with the N75 previously

11-16-2009, 10:29 AM
with the n75 only hooked up, i would hit 23 psi, then it would drop down to 12psi. then build up to about 18 or 19... such a headache. man...

11-16-2009, 01:21 PM
try bypassing the boost controller and run straight off the WG. Just the boost source and WG and you should only hit what the WG spring is set for. If it still goes that high you may need to replace the WG actuator.

11-16-2009, 01:28 PM
thanks low- to confirm, hook Wg lint to output from the compressor area?

thanks again

11-16-2009, 02:30 PM
Yup exactly from there to the wg.

11-16-2009, 05:05 PM
thats because the hallman works the opposite of what your thinking. The more you tighten it the more boost you'll get. At least with mine that is the way it is.

11-16-2009, 05:15 PM
maybe you can set it up as follows to help with the spike on the n75?


I know your boost controller is different, just something you can try.....

11-16-2009, 05:17 PM
clockwise more boost
counter less thats how mine works should be the same

11-16-2009, 07:44 PM
yeah i have it turn all the way out (counterclockwise) and the damn thing is over 2.5 bar... i am yet to go off the WG spring, but will try that tomorrow. just going to stay out of boost until i can get this figured out.

i am soo baffled.

11-16-2009, 07:48 PM
if you are overboosting with it all the way counterclockwise, have you tried it all the way clockwise? the worst that happens is it does the same thing.

11-16-2009, 09:31 PM
^^ yes ghost, i tried that as well. same thing happneing. So i will by pass the mbc and hook direct to WG, and see what happens. if i can have the boost drop from this, then what would that mean is broke? again, many thanks!