Help reading a turbo basemap?

[mykwikcoupe]

So my turbo is the Precision sc34 with a stage 3 turbine. i can give whatever measurements one is needed to help me out. I dont know how to read the basemap so im wondering if someone can help. Im trying to figure out what compression pistons to use for my biuldup. Id love to be able to make the bottom end a squarebore but I doubt that the sidewalls will handle it.

With this in mind, and the cost of fuel right now. Assuming an all aluminum B20a with a fully race prepped head, edelbrock intake, 70mm TB, 680 injectors(or larger at this point), 2.5 inch downpipe into a 3 inch exhaust from the flex joint back.

The heat characteristics of aluminum are more beneficial than cast iron so I can in theory up the compression without detonation. Im wondering just how high though. 92 is the highest octane I can get regularly in my location. Id like to keep the compression up so help with the low rev drivablility of the car and hopfully not require me to rev to hell and gone to maximize the turbos efficiencies. Im thinking something in the 9.5:1 or as high as 10:1 in a 81.5mm bore.

http://www.precisionturbo.net/turboc...tegory_id=3026

Im not sure where to find the maps at but ill keep loooking. The stupid turbo doesnt have a model number that would make it so much easier

[Accordtheory]

. I dont know how to read the basemap so im wondering if someone can help. Im trying to figure out what compression pistons to use for my biuldup. Id love to be able to make the bottom end a squarebore but I doubt that the sidewalls will handle it.

I have no idea what you're talking about.. When you say basemap, do you really mean turbo compressor efficiency graph? "Squarebore"..? Are you talking about bore/stroke ratio? Most hondas are undersquare, ie, 81mmbore x87.2mm stroke is a gsr. The common exception is the 77mm stroke b16, with the same bore. However, changing the pistons does not affect that, changing the stroke (crank) does, so wtf are you talking about? lol..

I'd choose somewhere between 9.3-10:1 for your static compression..
With my endyn forced induction pistons and gsr head, my gsr clone's's static CR is about9.7:1, if I'm not mistaken. That's fairly typical of a boosted honda..

[mykwikcoupe]

yeah thats i tthe compressor efficiency graph.

I was also thinking about 9.5-9.7:1 pistons but Im wondering why my point will sit on the graph

[Accordtheory]

A compressor graph is adiabatic efficiency vs turbo rpm, mass flow rate, and pressure ratio..so where your point on the graph will be is a function of the turbo's pressure ratio vs your engine's volumetric efficiency at that rpm. Kind of a complex thing to figure out.

[89T]

here is some good reading for you.
http://www.z31performance.com/writeu...selection.html

[AccordEpicenter]

9.5:1 should be fine, 10:1 comp will require a finer tune but could be done with great results, its all in the tune. If you have it setup well either one will be fine.