K03/04 turbo on I5's (and turbo size for that matter)

[JShadzi at aol.com]

Jim,

First off, that would have to be a serious custom jobbie to fit anywhere near an MC exh. manifold, are they building a custom turbine housing?  It would likely be easier to fit a Garrett or other turbo as it would be a K0 series turbo.

Second, my recent thoughts and expereince drag racing lead me to believe that going to a smaller turbo than a K26 is a serious step in the wrong direction for any power over 200hp.  Initially my reaction to my high intake air temps was "I must need a bigger intercooler".  After more research, I believe my problem is not with my IC, but my turbo.  

Intake air temp increase in a turbo application is directly proportional to the Turbo's efficiency.  In my case, even my RS2 sized IC is failing because the K26 I am running at 15+ psi is completely out of its range of effieciency.  At these levels, the K26 is just beating air, flow is terrible and the turbine blade is surging past super sonic.  

My current plans are to build a tube header and use a T3/T4 turbo.  With this setup, I believe that my intake air temps are will be much lower due to the much higher turbo efficiency, and the increased flow 
capabilities will result in much higher power levels (up to 400hp).

Often, many "turbo heads" are obsessed with Boost Pressure.  I will state here that I an unimpressed with anyone running more than 12-14psi through a K-26 on a 2.2 10v.  I do not belive that a K26 should be run at boost levels any higher, to do so will simply result in elevated intake temps and less hp.  I have been there, turning the boost up on a k26, and the increases are always real good up to about 14psi, were after that the car almost feels slower.  The K24 aggrivates the problem further, being even less efficient and flowing less too.  

Bigger turbos will produce more power with less boost, this is a function of lower intake temps and higher rates of CFM.  Flow is just as critical as pressure, and you just can't flow very much gas though the tiny K-24, the 26 is slightly better, the K03 is rediculous ( have you seen one, the inlet turbine is about 3/4"!), and the K04 is not even the size of the K24.

You guys out there running 20+ psi in a K24 or 26, 10v or 20v really out to consider what all that pressure is really accomplishing (heat).

Jim, my recommendation for you would be to look for a more efficient turbo.  Any of the Garret turbos can be made to fit the stock exh. manifold and downpipe, and are a much better choice than anything in the K^3 line, for much cheaper.  Turbo lag is a reality in turbo cars that produce power.  If you want quick spool up, then you will be limited to about 200hp and a 5kRPM motor, a big trade off IMO.  With the T3/T4 hybrid, full boost will be had by about 3200RPM (depends on the AR ofcourse), and flow will be unrestricted thoughout the whole RPM range.  Most importantly, efficiency will be maximized, and intake temps will be manageable.  The factory gets away with the K03 because it is only producing 170hp at most.  I recently saw a chipped  A4 1.8t make 130hp at the wheels, was supposed to make 210 at the crank (theoretically), but you think it could do that will all that heat its making?

Anyway, sorry for the rant all, I will keep you posted on my header/turbo upgrade.

Javad Shadzi
80tq.com



<<Ok, has anyone tried fitting a K03/04 turbo on one of
our 10V turbo engines?  I've talked to Turbo
Engineering Corp in CO and they assure me it will
spool much quicker and obviously flow more air than
the K26.  They said they have done this on more than a
few cars.  So, are you guys out there?  Did anyone go
to the s-cars nationals and talk with TEC about this? 
I'm going back and forth on if I want to get a new
turbo, or RS2 bumber+Spearco first.  I'll eventually
have both, but whichever I choose to do second will be
a ways off.  If I do get the turbo I'll upgrade to a
200 20v single pass intercooler to free up some
airflow.
TIA

=====
Jim Green
'89 90tq 
http://www.geocities.com/jeg1976/>>