Counter-Intuitive Boost and the 3B derived K24

[JShadzi at aol.com]

Sigh, thank you Bob for confirming what I have been preaching so much lately!

Its about flow, not boost, and lower boost with lower temps will flow more air that hot, high pressure air.  I'd say at the 12psi setting you are probably right at a good point of equilibrium for the K24.

Javad
80tq.com

In a message dated Tue, 30 Oct 2001 12:52:30 PM Eastern Standard Time, robert_a_dupree at bankone.com writes:

>  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.