boost question again....

I was wondering if you guys know what psi would you get out of a JoeP mbc when it is adjusted all the way to 0psi? because on mine the lowest it goes to is 16psi, is that normal? If so, how can i drop the psi a little like 12 or 13psi? Thanks for any help you guys can give me...

The lowest you can set will be what your wastegate actuator spring is. Your 16g's actuator is roughly 10-11 psi, so thats the lowest you can go.

I would remove the Joe P from the loop, running a straight line from the source you use right to the WG actuator nipple. If its 10-11 psi, its a problem with the MBC not going low enough. If its still 16 psi, you have boost creep, and will need to do some porting or other mods to reduce it.

The lowest you can set will be what your wastegate actuator spring is. Your 16g's actuator is roughly 10-11 psi, so thats the lowest you can go.

I would remove the Joe P from the loop, running a straight line from the source you use right to the WG actuator nipple. If its 10-11 psi, its a problem with the MBC not going low enough. If its still 16 psi, you have boost creep, and will need to do some porting or other mods to reduce it.

Thanks!
I was wondering, when you say remove it from the loop and straight line from the souce? i don't actually understand. Sorry...im still a newb.

Thanks!
I was wondering, when you say remove it from the loop and straight line from the souce? i don't actually understand. Sorry...im still a newb.

Kevin is giving you a way to see if the problem is the MBC. If you remove the MBC from the car and run a vacuum line from the source (T from BOV hose) to the nipple on the WG, it will tell you when the wastegate is opening. That way there is nothing in between the two (the MBC actually tricks the WG into thinking the turbo is not producing as much boost as it really is). So by removing the MBC from the equation you can see exactly when the WG is opening (by the reading on you boost gauge).

Exactly. Remove variables so you can see what it really happening.

thanks guys...i tested it out today and the boost stayed at 10-11psi. So there is something wrong with my MBC...it is practically brand new, i don't know why there is something wrong with it...fu** What MBC would you guys suggest me getting that would be reliable and for a decent price? Thanks...

joeP should be good. try contacting them and see if you can get a free replacment. my guess is that you got a bad spring or something

Yeah, if that was unscrewed all the way the spring is still too strong. I hear he's pretty good with customer service, I'd get in touch with him. I know Chad lost the internals to his (or maybe I did) and he sent them out for cheap money.

JoeP's have a tendencey to have a tight spring. Mine did, but I just took it apart and cut a TINY TINY bit off the top of the spring. Works perfect now :)

That will work :) POSR style... :D

Thanks for the input fellas...i knew i wasn't trippin when my boost was too high, thanks!