[Es2] Re: [s-cars] MAF to intake side of turbo

Kenneth Keith auditude at gmail.com
Fri Jun 10 15:10:15 EDT 2005

"you now have a blow off valve, not a bypass valve so you have to tune
it properly to allow this condition."

I may have missed a post that skipped the eS2 list, but why would
relocating the maf change the type of bypass valve being used, in and
of itself?  Seems like you could put the maf between the intercooler
and the throttle body and still have a true bypass valve working
across the turbo, no?  Or do you, or did Mihea, mean that it "acts"
like you have a blowoff valve, even with a bypass valve, if you
relocate the maf?

There's probably something technical I don't yet understand, but it
would seem like the air at the MAF and MAP sensors would be the same
(correct reading relative to what matters to the engine) regardless of
whether the turbo is leaking to atmosphere or not.  It would be
different if the maf was in front of the turbo, since the leak would
be metered air, but with the maf after the turbo the "blown off" air
would not yet have been metered, so why would it matter?  This not to
say that moving the maf doesn't require a remap for other reasons. 
I'm just curious about the blowoff versus bypass valve comment.

Some people have mentioned being able to reprogram the Motronic so
that it doesn't use the maf sensor at all.  Mihnea has commented on it
in a old post on S2forum as well.  I can't go there and provide a link
however, as I can no longer browse discussion forums from work.  The
horror!  =O


On 6/10/05, Richard Tanimura <richard.tanimura at gmail.com> wrote:
> Trev,
> You mean that sooner or later we will all end up running speed-density?
> Rich
> On 6/10/05, Trevor Frank <tfrank at symyx.com> wrote:
> >
> > I talked to Mihnea at length about this, cuz I thought no, but he has
> > done it, and the real concern is....first custom software, as well you
> > now have a blow off valve, not a bypass valve so you have to tune it
> > properly to allow this condition.  Honestly at that point, I don't know
> > why you would even want to use a maf.
> >
> > -----Original Message-----
> > From: s-car-list-bounces at audifans.com
> > [mailto:s-car-list-bounces at audifans.com] On Behalf Of
> > Elijahallen92 at aol.com
> >
> > Hey guys, I've been reading about a few guys in the UK moving the maf to
> > the
> > intake side and having no issues. Anyone done this yet here? I am
> > thinking
> > of moving mine to the intake pipe just before the intake manifold right
> > before
> > where the ISV goes in. This will let me free up the turbo cold side and
> > go to
> > a  4" intake. Thanks for any input.
> >
> > Elijah

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