I installed my forge mbc and now im running 19psi with it turned all the way down. I sure i must have a leak in the system somewere. I switched the vac lines around on the mbc and it went up even higher. Im think i have it on right. The bass nipple goes to the side on the mbc and the black nipple on the turbo goes to in nipple on the bottom of the mbc i think the bottom is the inlet????

 

Which MBC do you have?

I have a hallman pro and the side nipple on the boost controller goes to the wastegate and the bottom nipple goes to the J-pipe (between the turbo and the LICP).

I think most MBC's are similar in there design, although I am not completely sure of this.

 

Did it not come with instructions?

 

Input line on bottom in from compressor housing, J Pipe, LICP, ETC...

Output line on the side goes to the WG

 

yes, its rather simple actually. If you have this and your still having an issue, it might be a problem with your wastegate, if your on a stock turbo then you shouldnt be having an issue with going lower then 19psi, because the stock boost is like 15.4 psi, think i read that somewhere, and of course if you were at stock boost before you started messing with the MBC then somethings up...

if your still having issues, take a look at your vacume lines and make sure theres no leaks or holes

 

forge instructions right in front of me..

bottom port= inlet "this port on the UNOS MBC needs to have a pressure source taken directly from the outlet of the turbo or from the intake manifold. we highly recommend and prefer that the source be taken from the outlet of the turbo of from intercooler piping as close to the turbo outlet as possible"..this would be the J pipe in most cases.

Side port = outlet.."this port on the UNOS is to have a pressure line connected to the pressure reference on the wastegate actuator of your turbo or external wastegate"

there are also multiple springs included and it says you may need to exeriment before the proper range of adjustment is found. are you using the stock wastegate actuator?

 

Will you give us more details please. Did you buy the car used? What turbo is on the car now and what wastegate? Post up a complete modlist. Did you plug off the nipple in the intake pipe when you installed the MBC?

I am thinking that maybe if the car had a previous owner he may have increased the wastegate spring pressure adjustment.

You can disconnect the MBC completely. Plug off any open hose ends and nipples etc. Run a length of 4mm hose from the nipple on the J-pipe directly to the nipple on the WGA. Now, what boost reading does this give you when you try a WOT run in 4th gear? If you get the same 19# reading then your WG is preloaded to 19#. That simple. If you get a reading between 10-12# then the WGA is not preloaded.