In reference to this thread, when perusing a few compressor maps, i noticed that, assuming b18c @ 84mm bore (2.0L) boosting 15 psi, the 4k rpm (50% max) line crosses the pressure ratio left of the surge line.

Is this a bad thing? (trying to learn as much as possible before inveseting the money.........a.k.a. doing it right the first time. )

EDIT: Some more info:

T04E 60-trim compressor

8k rpm:
Flow @ 15psi = 541.94 CFM (38.11 lb/min)
PR = 2.02

6k rpm:
Flow @ 15psi = 406.46 CFM (28.58 lb/min)
PR = 2.02

4k rpm:
Flow @ 15psi = 270.97 CFM (19.05 lb/min)

I'm sure there's something very simple that i'm not realizing, so bear with me. Baywatch is on, so I can't be expected to focus ALL my attention on this right now.


[Modified by zoomintegra, 2:00 PM 10/16/2002]

 

anyone?

 

My (educated guess) on surge limit is you are exceeding or falling below the pressure it takes to spin the turbo. Make sense? If you fall below, nothing happens, you just don't make boost. If you go beyond the surge limit, you just make some heat and reach max boost. Beyond the surge limit also generally overspins the turbo and can lead to premature failure.

I am no turbo technician, but I hope this helps you.

You could also talk to Terry @ www.innovativeturbo.com

These are the guys I use to build turbos and answer specific tech questions. I think you'll find him friendly and helpful.

 

thanks, it actually looks like i'll be good to go.