MBC install ?

james_gt · Post by **james_gt** » Fri Mar 26, 2004 9:53 pm

I just got one of these, I was wondering if I am supposed to completly bypass the stock boost control solenoid. I woul like some pictures of setups. Thanks

james

mTk · Post by **mTk** » Fri Mar 26, 2004 9:56 pm

I installed mine on wednesday night, i bypassed the stock solenoid. Took the hoses of from teh stock solenoid and put them onto the MBC.

MK

boostjunkie · Post by **boostjunkie** » Fri Mar 26, 2004 10:04 pm

Go here:

http://www.legacycentral.org/library/hbc.htm

Instructions should be similar to your boost controller, as long as it's a MBC.

vrg3 · Post by **vrg3** » Sat Mar 27, 2004 6:33 am

Woah, woah, no! Don't follow the instructions there; they tell you to use the intake manifold as a boost source rather than the compressor outlet. Search instead on here.

In a nutshell, though -- bypass the stock solenoid. Disconnect the sideways fittings (and cap off those nipples) and put your controller in between the hoses you pulled. It'd probably be better, though, to replace those hoses with shorter simpler ones.

LegacyT · Post by **LegacyT** » Sat Mar 27, 2004 12:46 pm

Is there any way to stopnthe stock boost solenoid from clicking when you bypass it? Can I just disconnect the electrical connector?

Mark,

vrg3 · Post by **vrg3** » Sat Mar 27, 2004 4:09 pm

If you disconnect it the ECU will throw a trouble code and go into a form of limp mode. If you're really intent on removing it you could replace it with a resistor so the ECU still sees a load. 470K 1/2-watt worked on my car.

But it's probably fine just to leave it alone... It's not gonna click any more or less than it used to.

LegacyT · Post by **LegacyT** » Sun Mar 28, 2004 11:55 am

strange thing is, when on stock boost my boost solenoid never clicked, never. As soon as I installed a mbc it clicks like craazy right above idle, its so loud and actually gets annoying, so I'd like it to stop it.

Mark,

vrg3 · Post by **vrg3** » Sun Mar 28, 2004 3:29 pm

It's actually doing the same thing as before, except the sound of the clicking isn't traveling down the vacuum hoses.

Did you cap off the fittings on the solenoid? If you haven't done that yet, that should muffle most of the sound.

LegacyT · Post by **LegacyT** » Sun Mar 28, 2004 4:46 pm

yup I capped both outlets with vacuum line caps. the clicking is loud as hell. I returned it to stock before for a test run and the clicking completely dissapeared, I tried as hard as I could try to hear it clicking, nothing. Then I reinstalled my mbc and it clicks again, argh.

Mark,

TurboLegacy · Post by **TurboLegacy** » Mon Mar 29, 2004 4:13 am

to install the mbc all i have to do is put it inplace of the boost controll solenoid. just put the two hoses that used to be on the solenoid and put it on the mbc?, is it that easy.

LegacyT · Post by **LegacyT** » Mon Mar 29, 2004 12:23 pm

yup just remember the one from the turbo is the goes into the boost source inlet on the mbc. And the line to the wastegate goes to the other nipple on the mbc. Don't mix the two up.

Mark,

TurboLegacy · Post by **TurboLegacy** » Mon Mar 29, 2004 4:10 pm

can i trust a boost controller from ebay for $20?

TurboLegacy · Post by **TurboLegacy** » Mon Mar 29, 2004 5:27 pm

on ebay there is a " best maual boost controller" for 9.79 buy it now, should i go for it?, looks very similar to a hallman. if any body looks at it, which end goes to which hose from the boost solenoid.

THAWA · Post by **THAWA** » Mon Mar 29, 2004 6:46 pm

Why not just make your own for less than that and save on shipping too?

LegacyT · Post by **LegacyT** » Mon Mar 29, 2004 11:49 pm

if your gonna buy an mbc buy a ball and spring type, not a bleed valve. Their much less accurate and you boost changes with the temperature, it becomes very annoying, trying to keep a constant level of boost day to day. All hallman mbc's are ball and spring and have a very good reputation.

Mark,

TurboLegacy · Post by **TurboLegacy** » Tue Mar 30, 2004 5:08 pm

i just bought one of the mbcs from ebay for 9.79 and 5.99 shipping, it is a ball and spring type, ill try it and tell you guys how it works. it wont be that big of a loss if it doesnt work right.

TurboLegacy · Post by **TurboLegacy** » Fri Apr 02, 2004 5:18 pm

LegacyT wrote:yup just remember the one from the turbo is the goes into the boost source inlet on the mbc. And the line to the wastegate goes to the other nipple on the mbc. Don't mix the two up.

Mark,

what would happen if the two accidentally got mixed up?

vrg3 · Post by **vrg3** » Fri Apr 02, 2004 5:19 pm

If the design of the controller is like that of most ball-and-spring MBCs, you'll get boost limited only by how much exhaust gas your engine can pump out. On a stock Legacy Turbo, that means it'll climb scarily fast to over 20 psi.

TurboLegacy · Post by **TurboLegacy** » Fri Apr 02, 2004 5:26 pm

what about the 13psi fuel cut?

vrg3 · Post by **vrg3** » Fri Apr 02, 2004 5:37 pm

I answered in the other thread:

http://bbs.legacycentral.org/viewtopic.php?p=54265

TurboLegacy · Post by **TurboLegacy** » Sun Apr 11, 2004 1:02 am

i installed my mbc today. i dont have a boost gauge, but i started at really low boost and turned it very little each run untill it was only a little faster than stock. i now have full boost up to redline. i think i am running around 9.5-10. i wont turn it up anymore till i get the boost gauge and an i/c.

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