1.
Ich habe bislang kein BOV verbaut, weil Crawford davon abrät. Die sagen, es bringt nichts (obwohl es ihnen Profit einbringen würde, BOVs zu verkaufen). Im Forum finden sich folgende Aussagen von Usern:
"Well that's a good point, but building boost that's lost from the system (i.e. from the BOV) takes a lot longer than the turbine stopping for a fraction of a second.
Try it out, i did and i never went back again.
The boost is always there thus the response is maximized instead of waiting for boost to build back up between shifts.
The only thing is longevity of your turbo is reduced...but the question is how long will the turbo last running no BOV? I think Crawford's been running their car like that for a long time and don't know the limit yet. Nor have i seen any damage on my own car. Note that both turbos are ball bearing."
2.
Ist der "grosse" GT30R mit AR .82. Entsprechend der Empfehlung von Quirt Crawford: "We sell the .82 A/R with our kits as it gives the best all around performance. The 1.06 is best suited for drag racing and peak power but you will pay the price with turbo lag."
Aber auch der .82 GT30R ist nach meinen Berechnungen bei 2.6l und 19+ PSI irgendwann vom Durchfluss her überfordert. Deshalb geht es aber einer bestimmten Drehzahl langsam abwärts:
"I have done some further research:
Estimated Air flow in lbs/min of a 2.6L Engine.
.......................................................BOOST PRESSURE
.......RPMS.......................................22 PSI..........24 PSI
....3000 RPM..................................26 lbs/min....27 lbs/min
....4000 RPM..................................34 lbs/min....36 lbs/min
....5500 RPM..................................47 lbs/min....50 lbs/min
....7000 RPM..................................60 lbs/min....62 lbs/min
Max. airflow for a GT3076R (compressor wheel size 76.2mm, turbine wheel size 60.0mm, Turbine AR .82) should be 52lbs/min.
Consequently, somewhere between 5500 and 6000 RPMS @ 23.2 PSI (highest curve) my S4 should start to produce more airflow than the GT30R can handle. That's why the power output decreases. And this may also explain why the power decrease comes later when I decrease the boost pressure (lowest curve).
But does this allow me to conclude that there is no issue back pressure? And why does the power with the S4 package dynoed by Crawford not start to decrease until approx. 6200-6500 RPMS (if there is really no issue with back pressure or something like that)? Maybe the boost pressure was lower (someting like 20 PSI)?"
Bin aber nicht sicher, ob die o.g. Berechnungen so stimmen. Habe nur versucht, mir meine und andere Curves zu erklären. Vgl. ...
1. Ohne KAT
2. Mit KAT