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re: Euro wastegate spring

scottmo@tekig5.pen.tek.com (Scott John Mockry) writes:
>I have read the old postings about the computer mods/wastegate spring
>for the Audi turbos and I was wondering if the Euro wastegate spring for
>the 1986 5000CS Turbos can be purchased seperately without getting the
>computer mods done.

I think that this depends on how much the new spring increases the maximum
boost pressure. I'm pretty sure the '86 Turbos have an air line from the
intake manifold directly to the computer. This provides the pressure
reading for the guage as well as telling the computer what the pressure is.
The problem is that the computer has a pre-set limit on the maximum
pressure which is allowed and when intake pressure exceeds this it cuts off
the fuel. This safety device prevents an overboost from creating too much
power and blowing the head gasket or other nasty things. While it is
possible to disconnect this air line, it would leave you unprotected in the
case of the wastegate sticking (I've seen it happen) and it would also
cause the boost guage to read 1.0 bar all the time. The computer
modification (probably amoung other things) increases this maximum setting
to allow more boost/power, but still cuts the engine if things get out of
control. Basically, if you want to significantly increase the boost, you
have to buy the 'intended acceleration' chip (I just love that name :-) ).

-Chauncey Griggs
                   Science is just facts; just as houses are made of
  *  ^^  *         so is science made of facts; but a pile of stones is not
  *^^^^^^***       a house and a collection of facts is not necessarily
  *  ^  ^*  *                                       -Henri Poincaire'
  * :^)  *  *
  * >  < *  *   My opinions are purely my own (unless somebody agrees with
  *      ***      
  ********      Chauncey Griggs (grig0009@student.tc.umn.edu)