Re: New Math

[QSHIPQ@aol.com]

>upgrade always cam and exhaust? Is it not best to first find a good
 >compromise in a cam, free up restrictions in the exhaust and then play
 >around with boost, mixture and timing? Again a compromise with low end
 >torgue vs free flow 
 >needs to be delt with. Unrestrict your exhaust too much you lose low
 >end. Get too much lift you get lousy idle and again move your torgue to
 >high up the rev limit.
>>>> 
 This is ok for a N/A car, turbos are a special case (there's always one...)
 I would look at a turbo map first, then address boost equation, the cam
really is pretty far down on the mod list for performance gains in a turbo
motor...  If you got everything else, it;s the place to go...  Exhaust yes,
but for different reasons...  A turbine wants the free-est exhaust possible,
it really could car less about back pressure for torque, the faster the turbo
spools the faster the car will go....  Really torque is increased, what
decreases is "off boost" performance, remember a turbo is really N/A motor up
to 0 vaccuum, and a pretty low compression one at that...  Once on boost, no
restriction gives more torque on a turbo motor...  So really the trick is
back at the box, get the car moving with ignition advance to get to 0>
vacuum.....  So, basically, a 3in exhaust system is an improvement on a turbo
motor without regard to <0 vacuum....
>>>>>>>>>> 
 With forced induction there is the overlap
 problem too. Also what about manifolds and cylinder heads. There is that
 equation to contend with too. Do you port you head and manifolds to
 really enjoy a good ECU upgrade even though your ECU is more a timing
 map? As I said I'm a rookie here but it seems to me many of the age old
 rules apply. Get a good balance with a cam, exhaust and porting first to
 eliminate the factory restrictions.
>>>>>>>>>>

Careful on this....  Porting the heads and manifolds is a air flow argument,
one of many to apply to a turbo car...  What are you really doing by that in
a turbo car?  Eliminating restriction, which gives more flow and less heat...
 Back up some though....  Wouldn't you first want to address heat elsewhere
in the tweeks to increase volumetric efficiency?  Say a cooler running turbo,
or a larger IC, nary cracking the head on the audi....  Beware that turbos
also change inversely the design of the head work...  Since a turbo works
more efficiently as the flow to it increases, what does one do with the
valvetrain?
  >>>>So where is the starting point with forced induction? Do you go
 straight to the ECU and WG or follow the old rules first?
 Anton J.  >>
I have simpler rules, the racing one....  Bang 4 Bux, what do you get the
most from...  Easy answer there...  A box and WG mod runs you 500-1000USD
depending on "service" (see archives)...  2.0 bar pressure (and conveniently,
kkk designed the turbo to run here), all other things being equal, raises an
MC motor to the 220-225HP level....   That's 55 hp for 500USD = 9bux per
hp...  I've spent triple that for less....  So the rules have changed...  B4B
is the rule to follow now....  For that, the cam is waaaay down on the
list...  Your best cam profile will yield prolly 30hp on a totally tweeked MC
motor...  At what cost?  A decent Schrick is 600USD+++  and yields more like
20hp (since it is not a turbo cam, a N/A one) , that translates to 30USD++B4B
hp.... Lots of other places to play first....  And you haven't addressed the
inherent fuel problem that cam will exponentially create... 

So, really no surprise there are no turbo cams stock available after 4
years....  Turbos require some different thinking from the "old" school, the
audis make it easy to do the "new" math however...

My .02 arbitraged thru the peso

Scott