Re: 3.0 Bar Turbo Boost!?!?

[Dave Lawson <dlawson@digitalglobe.com>]

Mark,
<<
Ned's (Intended Acceleration) new price list for his Audi turbo mods. lists a
3.0 Bar (24-25psig) computer modification for both the 91 200(20v)TQ's and
the S4/S6- I think he is calling this stage V.  He apparently modifies the
chips as well as changes out the pressure transducer.  This computer mod.
must be done in conjunction with the higher flow exhaust manifold and sport
turbo (RS2 turbo I believe) so it aint cheap but he's claiming 330 horses for
the 200TQ and 340 horses for the S4/S6.  Just want to know what you all think
about running that much boost on such a high compression engine (9.3 to 1)
using the pump gas - the best stuff I can buy in Colorado is 91 octane.  
>>

3.0 bar == 29.4 psig not 24-25 as stated above

When you run this in Denver you will end up with 31.7 psi boost, which
yields a pressure ratio of 3.55. That number is way up there on the porsche
930 K27 compressor map. And it's off the scale, ie. bad, on the 944 turbo
K26 map. I don't have the Audi maps or the sport turbo maps for a real 
reading, but I would keep on talking to PDQSHIP. I hear the 20V motronic
systems have altitude sensors for some compensation, but not to familiar
with the system.

At this boost pressure, the air flow numbers are pretty high. If it were me wanting
to step into the jet stream, I would start looking at the design of the engine 
system, not just piece parts from a vendor. Exhaust manifolds and turbos are 
needed, but the down pipe, high flow cats and big exhaust could also be on 
the list.

A fellow here in CO was building such an engine to go into his ur-quattro. 
Haven't heard any progress reports of late, but he had the RS2 turbo and 
manifold, he picked up a sport q downpipe, etc. To deal with the increased
thermal loads he had a custom AL radiator fabricated along with an
oversized oil cooler. The list goes on...

<<
Ihave had some discussions with Scott (PDQSHIP) but wanted to solicit some
more discussion before I spend the big bucks on a bigger turbo and Ned's
computer mods (I already have the RS2 manifold, 2.3 Bar ECU, and K&N cone
filter on my 94 S4).  
>>

I would so some more research and think about what goal you are trying to 
achieve.
-
Dave
83 ur-q w/ 89 200 MC engine and soon a custom EPROM to deal with altitude