DriveSlowHomie

i put on the mbc last nite and turned up the boost to 9psi from 6psi...this is my first time working with a boost controller...is it suppose to suck in air, like a small vacuum leak at idle?...you can hear the sssssssss very loud and sucking in air at idle, which makes the idle higher...

we also had it hooked up on the wb on crome last nite...is there suppose to be a difference between my autometer boost guage and what crome reads(map)?...my wg has a half bar spring in it, boost gauge reads 7psi and crome only says 6psi...we figured that we would go by what crome says and and turn up boost accordingly...so we turned it up till crome read 9psi, now the boost guage reads like 10psi-11psi...is this safe and normal?...we set the boost cut off to 10psi and street tuned it

another quick newbie question since this is my first turbo setup and first time messing with this stuff...how the hell do you determine spool time(rpm)?...people say 3500-4000 rpm for full boost with t3/t4...im using a 54trim(dont know what a/r)...on mine the rpm jumps hella fast in first gear and i cant figure out if its spooling correctly(type r tranny)...it seems like i see full boost much later then 4000rpm though...boost and rpm almost climbs together it seems like...i double checked everything to make sure i dont have any boost leak...is it just my tranny?

notoriousB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cmGSR916 &raquo;</TD></TR><TR><TD CLASS="quote">i put on the mbc last nite and turned up the boost to 9psi from 6psi...this is my first time working with a boost controller...is it suppose to suck in air, like a small vacuum leak at idle?...you can hear the sssssssss very loud and sucking in air at idle, which makes the idle higher...
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I'm guessing your wastegate vacuum source is on the intake manifold, you're right the bleed valve on the MBC is causing a vacuum leak at idle. To get rid of that (w/ that MBC) you need to move the WG vacuum source either to the compressor housing or before the throttle body on the charge piping.

DriveSlowHomie

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">
I'm guessing your wastegate vacuum source is on the intake manifold, you're right the bleed valve on the MBC is causing a vacuum leak at idle. To get rid of that (w/ that MBC) you need to move the WG vacuum source either to the compressor housing or before the throttle body on the charge piping.</TD></TR></TABLE>

yea it is hooked up to the IM...will the boost pressure be exactly the same in the pipes and in the manifold?...can i just plug rewire it rite now or will i have to adjust again?

notoriousB

you'll probably have to adjust it a little if you hook it to the compressor housing to compensate for pressure drop across the intake manifold. no big deal tho.

DriveSlowHomie

so just to make sure...the psi in the compressor would be a lil higher than in the IM rite?...do u know approx. how much, up to 1psi difference or no?

notoriousB

no no boost will be lower at your current settings if you move from IM --&gt; compressor housing

DriveSlowHomie

thanks a bunch