[200q20v] RS2 & 3B - Fueling Around

[Ingo D. Rautenberg]

I run a Hoppen ECU and otherwise stock (save for upgraded distributor and
adjustable wastegate) engine.  My K24 is definitely getting tired at the
upper limits and I have toned things down to ~18-15 psi.  I have seen peaks
in the past of 26 psi (Yes, you read that correctly), which falls way beyond
the limits the K24 is designed for...hmm, maybe that's why I have oil oozing
from the end caps of my IC...  If you want to do things right and want to
explore 21+ PSI I'd definitely recommend upgrading exhaust manifold and
turbo (unless you're Bernie Benz --then don't replace it unless it's broken
;-).

Airflow at predifined boost levels is really a moot question, since you are
talking about the same thing.  Like Jon said, though, we aren't talking
about running at a static speed and must take into account acceleration and
torque (were' it's really at).  Sustained boost levels at higher rpms are
only possible with a bigger turbo and the RS2 or Garrett hybrid will do so
nicely.

My analogy from when I took diving lessons a lifetime ago:  Ever tried to
tread water with your hands up in the air?  There is a certain range of
exertion/efficiency that will allow you to do this for, say 10 minutes or
so.  Anything below that and you sink and much above that and you're just
churning water and tiring yourself out quicker.

What rpm range do you like to run your motor at and where does it run better
at?  If the answer is 2.25-5k, the k24 is probably perfect for you.  If you
prefer 2.7-6k+ (like I do), RS2 or Garret Hybrid would better suit you. Then
there's always the question of how much you are willing to pay (short and
long term).  I haven't decided on that one yet.  Parts:  $3000 bare minimum
(RS2 + exhaust manifold+ chip) vs $400-600 to repair K24.

All upgrades pose a risk.  You just need to figure out which end of the
scale you want to be on.  You can drive the car well under it's limits and
it will last a very, very long time (Bernie's 148k+ UFO's come to mind), or
you can modify the hell out of it and take your chances.  IMO anything over
340 hp will require replacement of rods (unless you want to bend your own,
of course).

Ingo