300 kPa Pressure Transducer

["Ned Ritchie" <NED@IntendedAcceleration.com>]

I noticed some discussion regarding the 3.0 BAR transducer on the list
today, and decided to comment.

At least as early as 1989 Audi Sport, Lehmann, and other turners were using
3.0 BAR pressure transducers!

This was necessary as pressures were above 2.5 BAR.  The original ones were
hand made and very, very expensive, and usually not available.  John
Buffum's S2, that his stepson Paul successfully campaigned in the SCCA Pro
Rallys, ran with one of these hand made ones.  At that time I was begging
Audi Sport and Bosch's sport department  for access to these at over $680.00
each.  They never supplied me any.  Recently there was a limited supply of
some mass produced ones.  Still expensive, but I think I bought most of what
is left, and have an outstanding order for more.

The 2.0 BAR transducer in all the turbo cars prior to the S4 just doesn't
cut it.  Except for very mild modifications these cars will exceed the
limits of the pressure transducers contained within.

When you correctly calculate it out the turbo coupe, the 5000 T, 100 T and
200 should not be pushed over 14.3 psig unless some scaling is done with
resistors or something to allow higher boost.  Some of you will call this
tricking the computer.

The '91 200 needs at least the 250 kPa transducer as found in the S4.
Reasonably high boost pressures without upgrading the 200 kPa transducer is
asking for trouble as the engine management system is just lost.

We've made these subtle modifications for years and all the IA Stage III
packages use a 250 kPa transducer.  We've been using the 3.0 BAR pressure
transducer in some of our 1991 200 TQ mods and in several S4 packages when
the power is over 350hp.  This is one reason why these cars always ran
better and stronger.

We have the 300 kPa transducer in Scott Lampkin's Nitrous fed S4, my 200,
Alex Neckas's 4000, and a couple cars on the east coast to name a few.

I regularly run up to 94 inches Hg with my car!  Check my tech tip on BAR
conversion published as the Quattro Quarterly's first tech tip to see how
many BAR that is.

A copy can be found at:    http://www.intendedacceleration.com/
Click on Tech Tips.

In a week or so when I find some more time I'll comment on the limitations
of the RS2 Manifold!

Ned Ritchie
Intended Acceleration