Jwbetley

I would assume that this (below) would be the ideal set-up for a MBC on an external WG; yes? I am not so sure what the purpose of the top fitting is on the WG. I'd prefer not to use it due to hood clearance issues. I usually run all of my vacuum lines straight from the break booster but I have a fitting on my turbo and would like to utilize it.



The search contains a lot of vague information on this, no pictures or daigrams. Thats why I'm asking.

-Justin

GsrRussell

That is how I have my MBC ran. I believe the top port is for Electronic Boost Controllers.

Kyle R

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GsrRussell &raquo;</TD></TR><TR><TD CLASS="quote">That is how I have my MBC ran. I believe the top port is for Electronic Boost Controllers.</TD></TR></TABLE>

Correct.

90 JDM EF8

iTrader: (1)

from what i was told by my tuner it is better to run both top and bottom even with a manual boost controller because it will stabalize boost pressure better

Jwbetley

That would mean that you putting pressure on above and below the orifice inside the wastegate. That wouldn't make sense. But maybe I am wrong.

90 JDM EF8

iTrader: (1)

well i will know monday when i retune so i will let you know if it makes a difference...he wouldnt tell me to do something if it wasnt right...hes the tuner of the fastest hondas in las vegas so i trust him...i even checked my greddy manual boost controller instructions and it even says to route it top and bottom also

pjr710

so did we find out if you hook it to the top or just on the side?

ralph11sec

this has been tackled over again.

if you have a tial (or same) wg, you can run the side nipple to the ( '&gt;' logo ) of your mbc, and then the other one goes to a boost source. like chargepipe or intake manifold.

in this way, you are restricting the pressure that goes to the side of the wg before it opens.

OR

you can have the top nipple, and side nipple of your wg used together by teeing it and lining the mbc on the top nipple.
in this way, you are adding a 'restricted' counterforce on the top of the diaghram of the wg before it will open.

so lets say your spring is rated @ 1bar to open.
and you want to boost 1.5bar.
so the side nipple senses 1.5bar right, and you want the wg to open. so you should have .5bar on the top of the diaghram of wg so it will hold .5bar more than the spring pressure.

pjr710

aight dont want to be a pain .. but i have my wastegate hooked up to my compressor right now .. i still gotta hook it to a vac source?

96lsvtec-t

i had mine on the top side to add pressure on top of the spring, but when i took it to get tuned, he moved it to the other side to bleed off air rather than add pressure to the top... he said i had it wrong before and the top nipple is only for electronic boost controllers.....

pjr710

yea i'll ask my tuner tomorow what i should do

ralph11sec

no, thats great.

thats the best boost source.

the only time you hook it up to your manifold is that if you dont have a fitting off the compressor.

pjr710

aight so compressor to boost controller .. then boost controller to side port?

ralph11sec

yes sir!

but make sure the mbc is not reversed. i am not entirely sure if some mbcs can go either way.
turboxs, greddy, etc, only go one way. the '&lt;' sign goes to the boost source. and the other one of course goes to the side port

pjr710

aight cool .. thx

743 Stunna

so if i run my mbc to the side port i can just leave the top open?

HiProfile

Yes. Think about it, once pressure pusing in from the line/fitting overcomes the spring rating, it moves the valve. It keeps moving it until boost stops climbing.

An EBC uses the top hole to force air into the top to close the valve until desired boost level is reached. A MBC only stops the pressure until it hits the right pressure, then allows air to push open the valve.


BTW using the compressor nipple for the WG (and for the EBC's sensor) will mean different temps of the FMIC (such as cold in the rain) will lead to slightly varying boost pressures, and thus varying levels of air temp. A vac source right off the manifold will keep boost consistent, although air temps change a bit. The manifold source will also close the WG a little quicker when you shift, meaning more gasses to keep the turbine moving. None of this is enough to really worry about, just FYI.

743 Stunna

thank you