Compression ratio and compression test readings.

[Howard Chu]

> Date: Fri, 19 Oct 2001 19:41:40 -0700
> From: "Bob Wooten" <r71chevy at earthlink.net>

> Wow, that spread sheet is cool.  It appears that it assumes one turbo, is
> there a benefit to "substituting" another turbo in for the one that is
> listed there?  is there a way to do that.

> Is there a way to download the spread sheet or am I being a dope?

I'm going to have to call you a dope! There are 5 different turbo maps
in that sheet, not just one! You just have to toggle the "Compressor"
listbox in the middle to choose one. And you can create more pages with
other maps if you want. I don't have an automated program for doing that
though, you have to do it by hand. And you are of course free to download
and save that sheet, just go to the parent page and use "Save As" on the
link.

The procedure for entering map data is very tedious, it goes like this:
find an image of the compressor map you want, and load it up in a graphics
editing program that shows you X,Y cursor coordinates. Mouse around to all
of the points you want to plot, and record the X,Y positions. Scale them
according to the dimensions of the image, and you've got CFM/PSI coordinates
for the spreadsheet. Look at an existing map page to see how the data is
organized; you cannot use more rows or columns than an existing map.

All of the data you provide has to go into a page formatted similarly to the
other compressor map pages. The name of the page should be some meaningful
version of the compressor map name. You also have to add the page name to
column Q of the "Selected Map" page. Finally, you have to tell the selector
box on the "AirFlow" page that you've added a new entry. Right click on the
Compressor selector box, select Format Control, and increase the Input Range
field by one row. Currently the field is "SelectedMap!$Q$1:$Q$5"; if you add
one new entry to column Q your range should be "SelectedMap!$Q$1:$Q$6".

If anyone would like to contribute more maps, please do. Just email to me...
I created the first 4 and the T04E46 was contributed. If you have a program
that can vectorize a bitmap image file and list intersection coordinates,
that would be pretty cool too, to help automate the generation of maps.

> Howard Chu wrote:
>
> > I recall seeing the formulas in the Bosch Automotive Handbook. I've
> > incorporated those formulas in my turbosize spreadsheet.
> >   http://people.we.mediaone.net/hyc/dyno/turbosize.xls
>

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc

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