NefMoto

Hello, fellow tuners!  :)
So I've found K03 compressor map and started to work with it but since car is running E85 I'm not sure if I should follow it or maybe the turbo can push more boost eficiently on E85?

I'm not sure that I read that right!

Your asking if changing fuels will alter the efficiency of something that pumps air?

in other words, if E85 which produces cooling effect in cylinders will extend the K03 efficiency range? (or even simpler: Can I let let my turbo boost upto higher RPMs before lowering it when on E85)

Also I have revese-converted pressure ratio to boost and found out that K03 can push max 1.92BAR @ efficiency 70%?? (please check image attached, pressure ratio around 2.9 & 159 CFM)

Conversion done this way:

PRESSURE = (14.7 + BOOST_PSI) / 14.7
PRESSURE * 14.7 = 14.7 + BOOST_PSI
BOOST_PSI = (PRESSURE * 14.7) - 14.7
BOOST_BAR = BOOST_PSI * 0.0689475728

Am I right?

Using very cool calculator @ http://www.lovehorsepower.com/joomla/index.php?option=com_content&view=article&id=35:compressor-flow-map-calculator&catid=8:mr2-helpful-stuff&Itemid=49 (http://www.lovehorsepower.com/joomla/index.php?option=com_content&view=article&id=35:compressor-flow-map-calculator&catid=8:mr2-helpful-stuff&Itemid=49) I have managed to update K03 map with some useful data (see image attached). I hope it will help someone besides me ;)

firstly your on the surge line, secondly i dont think you stand a chance of getting a k03 on your engine into that effecency area, and why would you, its probably the least effecient part of the map.

Small mistake on my compressor map (new version attached)

If I understand map correctly then this point is at the 70 percent efficiency "island". Or am I wrong?

OK, so I've compiled my boost table using some math... What do you think?

Yes it is 70% but that is assuming you can get the compressor to get there in the first place.

24psi @ 2k?

Yes, this is ignoring real life factors, I would log my actual boost and see deviation between requested and actual ant then fix this ;)

1) the s4wiki has had the k03 compressor map from the beginning
2) ecuxplot can plot pr vs flow
3) everybody loves pushing k03/k04s to the surge/overspin lines, damn the efficiency islands.

not sure why 3) happens as much as it does, but there you go

Yes, I have used the s4wiki compressor map... Also, I'm not going over the surge line, keeping everything within ~70% of efficiency (except for very low rpm) but maxing out this island to the limits...
My main question still is unanswered. So E85 effects turbo possibilities or not? Those RPM lines were calculated using 1.8T engine size and, if I'm not mistaken, regular fuel. Wouldn't they be different for E85?

P.S>
Pr = (14.7 + Boost_in_psi) / 14.7 is the pressure ratio. What is this number 14.7? Stoich AFR?

if this is AFR then whole CFM formula should get different results for E85:
CFM = (L x RPM x VE x Pr) / 5660

Where L = engine capacity in liters
RPM = maximum engine speed (we'll adjust this later)
VE = engine volumetric efficiency.  From A. Graham Bell's book Forced Induction Performance Tuning some good values for VE are:
Stock 2-valve = 85%
Stock 4-valve = 90%
Street modified = 93%
Competition = 105%
Pr = pressure ratio

IAT realy depends on your ic and compressor efficiency .

turbo possibilities are not dependent to fuel type but boost capabilities can  .
in some case you are limited by EGT, and the knock resistence of E85 can, in those case, let you raise the boost .

s4/rs4 K03/K04 are not the same as 1.8t k03/k04 .

so K03-1870 EXA is wrong one? :o So which one should I use for my K03 on 2001 1.8T AWT? :o

BTW: Found another compressor map also for K03...

The compressor map is useful to help you pick a correctly sized turbo.
Once the turbo is on the car, it is mostly useful to make sure you are not exceeding the manufacturer specs (which most people are doing anyway when tuning).

If it's already fitted to the car, then just boost until it stops making power or you hit some sort of component limit... then depending how the car is used, back down an amount, to leave a margin (less boost = more timing, less EGT, lower IAT).

Also, the compressor map shows how efficiently the compressor can compress air at which flow and pressure ratio and that's pretty much it.
Why you put fuel type into the discussion is beyond me.