Anyone have thoughts on a Borg-warner turbo for my 2.7l?

[djb25]

Hi everyone,

Last year I turbocharged my 2.7l using a cheap eBay intercooler and a fairly cheap Chinese turbocharger. The turbo is some sort of plain-bearing GT30 knockoff. It actually works surprisingly well. The project was more of a "I wonder if I can do this" type of project, rather than a super-well-planned build.

I've been thinking about replacing the turbo with something better-suited to the motor, but I'm having a hard time really determine how to match a turbo to my engine. I have that fairly well-known turbocharging book (the name and author of which escapes me at the moment), but I'm not 100 percent sure if I'm looking at turbo maps in the most accurate way.

Here's just a rough set of numbers put into the Borg-warner matchbot. This link should take you right to the info I've input:

BorgWarner MatchBot

I'm just not sure if I'm doing this right.

For example, here's the map for one of the s200sx-e turbos.



That seems pretty good to me. It's making 10 psi at 3000 RPM and holding it all the way to 6500 RPM.

But that leads to the turbine chart.


That seems to put me in the 64mm 0.92 a/r and/or 63mm 0.84 a/r.

But that has me going from 30% wastegate at 2000 rpm to about 50% at 6500 rpm. I doubt my waste gate is going to be 30% open at 2000 rpm... Does this stuff actually matter?

Anyone have an opinion on this stuff?

[djb25]

Photos didn't work for some reason.

Here's the compressor map:



Turbine: