Mailing List flyrotary@lancaironline.net Message #66227
From: lehanover lehanover@aol.com <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Dyno Sheet
Date: Sat, 8 Aug 2020 01:41:17 +0000 (UTC)
To: <flyrotary@lancaironline.net>
Here is one of the SAE specs, you need three. The SAE page says about 80 USD each.  You or we.. need to check with a dyno operator for hard copies or a copied disc. Or the old spec if a new one was issued.  LEH

http://www.bigdynodatabase.com/DynoCF.php


Thanks Lynn.

Steve

> On 8 Aug 2020, at 9:11 am, lehanover lehanover@aol.com <flyrotary@lancaironline.net> wrote:
>
> Not your fault.    I am old and easily confused.......
>
> After each dyno pass, you compare each number recovered near or in the inlet tract wherever your fresh air supply is recovered. So as to establish the "Weather" or air conditions the engine is "seeing"
>
> These are large printed (size C formats) years back. It is now probably a spread sheet for very quick calculations. For example you are looking for some help at the bottom end to help get out of corners a bit better. You change idle jets closer to best power at 7,500 RPM then add a bit of accelerator pump. I made movies of the gauges for review. In two days of testing (for this one problem) we have many different inlet air temps. Many barometric pressures and many humidity readings. So each pass produces a different raw HP
> reading. You look on the SAE chart for the number you just recovered and follow the column to the SAE correction number temp. or pressure or humidity and you fill in your home made form with the "NEW" SAE multiplier.  Since all of the charts start at sea level each SAE multiplier will reduce the raw HP number. But, all of the passes are now in the same format as all of the variables are removed. I could get 2 or 3 good readings using the movies. The throttle is always wide open and the test RPM is controlled with a water brake load cell.
>
> In most cases your great idea will cost you HP. but every so often Jackpot....4 corrected HP.    Modern dynos have this stuff built into their computers so the numbers you see are already corrected to sea level. In olden times they were not. Lynn E. Hanover 
>
>
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster