Cannot dial in boost with MBC

Miatamad · Post by **Miatamad** » Fri May 04, 2007 10:59 am

Hi - Here is my problem,

Now that I have the new clutch in - I can raise my boost - or so I thought ...

I have a MBC installed between the housing on the turbo and the wastegate.

If I have the w/gate can set to 5PSI - I cannot change boost at all higher regardless of the amount I dial in the MBC - even all the way. Seams that its simply not having any impact.

When I adjust the can I get higher boost -- ??? again independent of the MBC setting.

SLYDIT · Post by **SLYDIT** » Fri May 04, 2007 5:21 pm

double check that you havent got it backwards..

What type of mbc is it ?
you should be able to get some adjustment, the only thing that will stop a bleed type mbc from operating is that the bleed port is blocked. or that the restrictor isnt small enough....

bleed type mbc's usually have a smaller inlet hole than outlet. if its connected ,or the restrictor isnt small enough then it wont work because the amount of air entering the can is more than the mbc can bleed off.

Miatamad · Post by **Miatamad** » Sun May 06, 2007 11:23 am

I think the problem was my wastegate can as opposed to the boost controller - I think that its allowing the exchaust to open as soon as I get near positive pressure. Will know more on Monday.

poison · Post by **poison** » Sun May 06, 2007 12:49 pm

That's interesting, I was thinking the same as I have an EBC and would have left the waste gate set on 5 if running at 8. Mine you mine is from Hong Kong so the instructions are miserable.

It's not possibly your blow off is it???

Miatamad · Post by **Miatamad** » Mon May 07, 2007 9:30 am

No - the blow off closes fine.

I think that I twisted the 'long arm' (technical term) adjusting the
length of it - thus I ruined the diaphragm. This means that despite any
setting on the boost controller side, the exhaust port is opening as
soon as the car is getting positive pressure (you can hear it).

I'm trying to find a new can this morning (anyone got an idea where to
buy one on the Shore??)

Its probably the same problem I had with my EBC - so once I have it
running manual Ill go straight to electronic boost control.

C

SLYDIT · Post by **SLYDIT** » Mon May 07, 2007 2:42 pm

what sort of turbo is it?
if its a garret then you could maybe get one from the Nissan boys at www.silviaclub.org.nz or skylines downunder...

id hate to think what a new one costs from a supplier here in NZ... if you want new then id try from a U.S vendor like atp turbo or similar.

poison · Post by **poison** » Mon May 07, 2007 6:48 pm

Alltech Ph 443-6511
110 Wairau Rd

They are a Garrett parts and repair agent.