Can't get my MBC to work right

[phalanx]

Ok I just got a $10.00 ball and spring MBC I got off ebay(looks exactly like a joe p) If I floor it, it goes up to 20-22psi and backs slowly to like 17psi. If I turn the screw anymore it will fall out! Tightning it increases boost and backing off decreases boost correct? Now funny thing is my boost level was the same before I installed the MBC, I bought the MBC so I could lower the boost to like 15psi. Perhaps it can't be lowered?? I did install it correctly right? I disconnected both hoses from the wastegate solenoid, the turbo inlet and the the wastegate itself, I pluged the turbo inlet. I then cut the hose going into the BOV and connected them together with a T. I ran a new hose from the T to the bottom of the MBC. I then ran another hose from the side inlet of the MBC to the wastegate. Correct?

 

[kraka]

hmmm..could this problem b b/c u bought a $10 boost controller off ebay???

 

[phalanx]

Perhaps, what MBC do you recommend?

 

[doug]

Run a hose directly from the compressor nipple on the turbo to the wastegate actuator nipple. Do a few pulls to see what the boost reads-- whatever it is, that's the minimum boost you can run. On a T-25 it's typically 9-11 PSI, which is what the actuator spring strength is.

 

[phalanx]

try switching your hose connections to the MBC around, cause tightening it should decrease boost not increase it. Or maybe your hoses are too big.

are you sure?

 

[Syndicate13]

Tightening the screw will put more pressure on the spring, which in turn will make it harder for the air to push the ball up to flow to the WG, therefore increasing boost.

 

[phalanx]

Tightening the screw will put more pressure on the spring, which in turn will make it harder for the air to push the ball up to flow to the WG, therefore increasing boost.

yeah thats what I though. Anyway I just ordered a joe p MBC, the one I have now its difficult to make fine adjustments, when I try to loosen the lock nut with the wrench it turns the screw with it.

 

[kraka]

thats a good idea!

 

[khartley]

Take it apart and cut the spring inside to shorten it, then you should be able to twist it further and lower your boost more.

 

[v8killerr1]

I had the same problem with my joe p the lowest i could get the boost to was 20psi with my 16g. I wanted to lower it since at the time i hadn't gotten my injectors yet so i ran a hose from the T on the bov hose to the wastegate nipple and i get 15psi with no creep. With a t25 you'll probably get 11-12.

 

[Defiant]

im very tired, im thinking backwards, sorry for the misinformation.

(N/P)

 

[Defiant]

An MBC usually can't lower boost levels.

 

[goonie]

Ok I just got a $10.00 ball and spring MBC I got off ebay(looks exactly like a joe p) If I floor it, it goes up to 20-22psi and backs slowly to like 17psi. If I turn the screw anymore it will fall out! Tightning it increases boost and backing off decreases boost correct? Now funny thing is my boost level was the same before I installed the MBC, I bought the MBC so I could lower the boost to like 15psi. Perhaps it can't be lowered?? I did install it correctly right? I disconnected both hoses from the wastegate solenoid, the turbo inlet and the the wastegate itself, I pluged the turbo inlet. I then cut the hose going into the BOV and connected them together with a T. I ran a new hose from the T to the bottom of the MBC. I then ran another hose from the side inlet of the MBC to the wastegate. Correct?

take out the spring and replace it with a softer one that will lower your boost
i made my own mbc and it works fine check this site www.geocities.com/chmwatson/
there is a page about a diy mbc

 

[phalanx]

just a quick update: it was indeed the $10 ebay MBC. I ordered a joep MBC, installed it, turned the boost to its lowest and I got 12-14psi.

 

[sonicnofadz]

Yeah I am running the same MBC from ebay, when I got it, I couldn't get it to stop spiking up to 20 psi. Since then I cut the spring and now I have it safely at 10 psi with no creeping at all (even with EVOIII16G). Kicks arse

 

[RossY]

Yeah I am running the same MBC from ebay, when I got it, I couldn't get it to stop spiking up to 20 psi. Since then I cut the spring and now I have it safely at 10 psi with no creeping at all (even with EVOIII16G). Kicks arse

hmm, im in the same boat that you were in. Exactly how much of the spring did you cut to make your mbc work right?

 

[sonicnofadz]

just start off REALLY small then try it. I would say I had to cut off a total of about 1/3 of an inch before it would start regulating the boost properly at 10 psi (without the knob being twisted ALL the way out of the damn thing). If push comes to shove and you need a new spring, no biggy, just go to the hardware store. These ball and spring boost controllers work just as well as $150.00 boost controllers you can find elsewhere.