DIY_Racing

pt# 48935K25

IM doing the diy profec b type setup... Where you have two MBC's and a solenoid that controls them.. so you can have two boost setttings and not spend alot of money. Has anyone, or is anyone of you guys using this type of mbc??

thanks

DIY_Racing

ttt

johnisenglish

I don't use that kind, but for an alternate cheap but good setup, I use a pressure regulator (the kind used for air compressors) from homedepot that I picked up for about $15.

BudaKai

What parts would it take to make one? Is it like the spring and nball bearing type?

danl

I did it to my car except that I tied it into my shifter linkage so that I could run low boost in first gear, then switch to high boost in the later gears. Low boost would be at the wastegate actuater spring pressure (10psi) and then it would switch to MBC boost in later gears (usually something more than 15psi, close to 18 psi). Anyways it worked ok, but I ditched it because I liked modulating the throttle better. I'd just assume always have my boost set at the maxium safe level (somewhere around 15psi). Heck, i've been running 11.5 psi all winter now, thats enough power for me.

Don't know what to tell you from a performace standpoint except that you can't run any lower boost than your actuator pressure, and if you have a slight leak it will cause slow spoolup in the high boost setting due to bleeding away pressure signal from the wastegate.

johnisenglish

It uses a spring, and can be found in any hardware store that carries air compressor (I got mine from Home-Depot). All you have to do is turn the **** and it adjusts to where ever you set it. Here's a pic of it:



I have it setup so that the vacuum source from the Compressor runs into the Boost Controller (which it tied down to the radiator fan housing) and then goes to the wastegate


[Modified by johnisenglish, 4:53 PM 2/6/2003]

turbod16y7vtec

i got that same thing..i guess its ok.. but its hard as **** to set..

johnisenglish

Yeah, it took me about a day to get it where I wanted it, but once I figured it out, I wrote on the dial so that I can see how many turns it takes to get to whatever PSI I want.
IMHO, for $15, it's well worth it


[Modified by johnisenglish, 5:57 PM 2/6/2003]

turbod16y7vtec

aight i guess i will just keep trying..

johnisenglish

Well, if you're having trouble with it - here's a little tip.

Loosen it up all the way, and then find the point at which you just start to feel a little resistance when blowing through it - that should be about 1-2psi. From there, slightly tighten it to where you think 4 or 5 psi should be, and over the course of a few runs get it to exactly where you want it to be. Each time you adjust it, you might want to do as I did and leave a mark on the **** so that you can go back for refrence.
Also, this may seem obvious, but it's often overlooked - make sure that you have the vacuum signal going in the right direction. These things are only one way, so if you hook it up backwards, you wastegate is never going to see any boost
Hope that helps

civperc

what kind of solenoid are you using and where did you get it? I'm interested in your set-up ya got goin