Perrin manual boost controller anyone? help understanding/installing MBC - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

S13-KA24DET · 06-02-2007, 12:40 PM

bought off my friend, lost the instructions

#1. goes to the wastegate actuator(s) while..
#2. goes to the vac source/intake plenum?
or does it really matter?

and anyone running this MBC, just wondering how to set it at stock boost, how many turns clockwise (tighten) or counter-clockwise (loosen) per 1 PSI or what not

beetlejuice · 06-03-2007, 01:19 AM

Buy a boost gauge (if you haven't already).

I would suggest #2 going to the intake manifold.

There isn't an exact science when adjusting a mbc. I suggest a half turn at a time, then test at wide open throttle (on the street).

Repeat until desired boost is reached.

garbury · 06-03-2007, 01:35 AM

Well if it is a ball and spring, and they are in that order...then you want the line from the vacuum source to push immediately against the ball which will be controlled by the spring pressure.

Vacuum source - 1
To the Wastegate Actuator - 2

If you flip it around, then the boost pressure will just push the ball into place, blocking the nipple and your boost will spike since the wastegate actuator will never get any signal.

To tune it, just turn counter clockwise a ways (its better to just be too loose than too tight since too tight means too much boost. Too loose will just leave you at stock boost). then give it a good romp in 2nd or 3rd and keep tightening until you hit desired boost.

S13-KA24DET · 06-03-2007, 11:45 AM

alright i just tried that gary
but i tightened it all the way and it's still boosting at stock?
maybe the mbc is faulty or would you guys think having stock twin turbo's play a factor?
you think i should try replacing the spring with a stiffer one?

06-02-2007, 12:40 PM	#1
S13-KA24DET Leaky Injector Join Date: Aug 2005 Location: So. Cal Posts: 70 Trader Rating: (1) Feedback Score: 1 reviews	Perrin manual boost controller anyone? help understanding/installing MBC bought off my friend, lost the instructions #1. goes to the wastegate actuator(s) while.. #2. goes to the vac source/intake plenum? or does it really matter? and anyone running this MBC, just wondering how to set it at stock boost, how many turns clockwise (tighten) or counter-clockwise (loosen) per 1 PSI or what not

06-03-2007, 01:19 AM	#2
beetlejuice Leaky Injector Join Date: Jun 2005 Location: Me? Posts: 145 Trader Rating: (0) Feedback Score: 0 reviews	Buy a boost gauge (if you haven't already). I would suggest #2 going to the intake manifold. There isn't an exact science when adjusting a mbc. I suggest a half turn at a time, then test at wide open throttle (on the street). Repeat until desired boost is reached. __________________ jollydwarf.com

06-03-2007, 01:35 AM	#3
garbury Leaky Injector Join Date: Apr 2006 Location: Arizona Posts: 93 Trader Rating: (0) Feedback Score: 0 reviews	Well if it is a ball and spring, and they are in that order...then you want the line from the vacuum source to push immediately against the ball which will be controlled by the spring pressure. Vacuum source - 1 To the Wastegate Actuator - 2 If you flip it around, then the boost pressure will just push the ball into place, blocking the nipple and your boost will spike since the wastegate actuator will never get any signal. To tune it, just turn counter clockwise a ways (its better to just be too loose than too tight since too tight means too much boost. Too loose will just leave you at stock boost). then give it a good romp in 2nd or 3rd and keep tightening until you hit desired boost.

06-03-2007, 11:45 AM	#4
S13-KA24DET Leaky Injector Join Date: Aug 2005 Location: So. Cal Posts: 70 Trader Rating: (1) Feedback Score: 1 reviews	alright i just tried that gary but i tightened it all the way and it's still boosting at stock? maybe the mbc is faulty or would you guys think having stock twin turbo's play a factor? you think i should try replacing the spring with a stiffer one?