Re: Boost Controllers

["Janet Scruggs" <scruggs@mbay.net>]

Gentlepersons, again... I've been using an HKS EVC III to monitor and
control the boost in my '87 5KCSq for over a year now.  Manual control is
not the only non-OEM option.  The HKS is completely electronic and simply
bypasses the ECU's control over the wastegate frequency valve (WFV).  In
fact the HKS unit comes with it's own robust WFV which operates faster and
more positively than the OEM WFV.  That I am able to ascertain, the ECU is
neither "out of wack" nor even the least bit sad now that it no longer
controls the boost.  

So, the answer is... yes, you can separate the boost control, and probably
the ignition control, function from the ECU, at least on the MAC-11,
without apparent ill effects.  The HKS also has a fuzzy logic circuit that
"learns" the boost curve of your particular engine/turbo and is therefore
able to leave the WG closed longer and open it quicker to maintain the
boost level which you have previously selected.  The HKS also gives a
digital readout, in mmHg for vacuum and bar for pressure, and has an
overboost warning... which issues a rude beeping... done there been that...
when you forget to reset the overboost level after increasing the control
pressure level.   

I cannot speak from experience if the HKS, or other brand boost controller,
were to be applied to the ECU of the A4 as I've never been there.  Were I
to guess, and I believe that I will, I venture it would work as well in
that application, too.  

Regards, Gross Scruggs
------------------------------
> 
> Date: Thu, 09 Jul 1998 01:15:12 -0700
> From: Michael Zamarocy <mhdavion@earthlink.net>
> Subject: Re: Boost controllers
> 
> Ali, I have seen some of the posts, and it pretty much seems to boil down
> to the fact that the ECU controls almost everything. Where as the other
> type of cars have a mechanical boost control (I used to be able to just
> adjust a rod on my Mitsu Mirage Turbo, then later the Wollen Racing Team
> made my cig lighter into boost pressure regulator - a secret Showroom
Stock
> trick <G>) and you chip their ECU for timing and fuel mixture, I gather
> that ours has to work with each part together as a whole. And if you go
and
> add a manual control to it, it pretty much throws everything out of
whack.
> Meaning do you want to risk detonating your engine for a few pounds more
of
> boost that might only get you a second quicker? I'd suggest go the newer
> Hoppen 250HP kit route. Sure it is $4500, but it is MADE to work with
each
> other.
> 
> And for those on this list not familiar with the new Hoppen kit, it
> includes chip, modified manifolds, new larger turbo, cat-back exhaust
> system, and I think a few other items. And hey, it IS from Hoppen, the
> ex-VW/Audi Motorsports Guru.
> 
> At 02:25 AM 7/9/98 -0400, AJahed@aol.com wrote:
> >Hi,
> >
> >I was wondering if an HKS EVC or Greddy Profec could be used to increase
the
> >boost in an A4 1.8T?  Someone on the A4 board said that it "CAN'T" be
done on
> >Audi's and that the only way to increase boost in an A4 1.8T is by using
a
> >chip.  He used a lot of CAPITAL letters and !!! as if he was yelling ;)
> >Thought I'd post the question here and get some real answers.
> >
> >Best Regards,
> >Ali
> > 
> 
> - ----------------------------------------------
> Thanks
> Mike Z
>