Mailing List flyrotary@lancaironline.net Message #3254
From: Russell Duffy <13brv3@bellsouth.net>
Subject: turbo math
Date: Tue, 23 Sep 2003 14:34:14 -0500
To: Flyrotary List <flyrotary@lancaironline.net>
Message
Greetings,
 
I did some searching around, and found the basic gas formulas at this page- 
 
For my measured temps:
 

MAP / temp F / RPM

18” / 105 / 3000

20” / 128 / 4225

30” / 167 / 5000

36” / 196 / 5500

40” / 214 / 5700

44” / 228 / 5800

 

It appears that at my 36" MAP boost level, I have the same air density that I would have at NA, on the same 90F ambient day. 

 

Unfortunately, this air density is only part of the problem.  I'm guessing that exhaust backpressure is as much, if not more of an issue.  This leaves me still thinking that I'll need 5-6 psi of boost to break even with a good NA engine, but I'm becoming more comfortable with those figures.  

 

Rusty (off to the hanger to see if I can find a place for Mr. intercooler) 

 
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster