Counter-Intuitive Boost and the 3B derived K24

robert_a_dupree at robert_a_dupree at
Tue Oct 30 11:46:39 EST 2001

 I want to share my newly enlightened perspective on boost.  After I picked
up the '84 UrQ years ago I wanted to change to a quicker spooling turbo.
Scott J was able to source me a very nice, low milage K24 (from a 3B?) that
was even upgraded with ceramic coating in places.  Nifty.  After
installation I loved it; but soon found that I was cranking the boost
higher and higher, chasing 'neck-braking' acceleration.

Well my ECU on the UrQ isn't overly mod'd so my limit is anything less than
16psi indicated max boost on my guage.  Exceed 16.0psi and fuel pump shuts
down... hard!  Anyway so of course for the last 2 years I've been running
as close to the limit as possible.  For the last year or so I've been
bitching about heat-soak and needing fuel, intercooler and other mods and
whining about wanting MORE boost!  It should be noted that all along Scott
J. has been of the opinion that more boost wasn't the solution, but I
wouldn't listen!

This last weekend at the Chuck Price organized Gingerman track day I was a
little worried about beating the snot out of the UrQ so I decided to drop
my boost down a bit.  I don't have the LT-1Q anymore so I've got to be a
little conservative...  I can finally comprehend what Scott was trying to
say the whole time.  In my application 12-13psi indicated runs much more
powerfully and consistently all day long than 15psi does (except for an ice
cold engine).  I would be curious to find the ultimate intersection of
boost-pressure vs. intake temp to set the optimum performance.  Maybe it's
time to visit the newl opened 4-wheel dyno in the Chicago suburbs!!!

The other interesting thing of note.  I had complained before that I
thought the K24 fell on it's face (again in my application) beyond 5000RPM
and I really wanted to go back to a K26.  Well no more.  The K24 is
astounding when you can keep your intake cool and the turbo going
super-nova.  One final observation.  I replaced my trans wing mounts with
the 'sport' versions from Dialynx.  I can't tell if I've installed them
correctly (I've got extra parts) but they are a LOT stiffer.  A little too
much noise, but an amazing transformation in the overall responsive nature
of the car.  Dave Hackl got in it and could tell the improvement from the
right seat as well!  If anyone else is running these please contact me
private.  I want to talk about how you mounted them...

I'm done yack'n for now.

Rob Dupree
     '84 UrQ
     '88 5kTQ

This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you.

More information about the quattro mailing list