Download Engine Analyzer Pro User`s Manual

(C) Performance Trends Inc 2009
Engine Analyzer Pro
Chapter 2 Definitions
may flow better with the carb or throttle body than without. In these instances, you should provide an "optimum entrance" at the
carb pad, since the carb itself would be a significant restriction. An optimum entrance can be molded out of clay.
It may be more convenient to just flow the cylinder head with the intake and exhaust manifold/header installed, rather than
trying to develop "optimum adapters". If this is what you want to do, see Example 4.4.
If you did not exactly have an "optimum" adapter for obtaining Flow w/o Runner, then your Valve Flow Coef will be too low
and your Runner Flow Coef will be too high. Also see Examples 4.4 and 4.5.
Accurate determination of Runner Flow Coef has three advantages:
• You can more accurately swap manifold runners onto heads (in the computer) which have not been flowed
together.
• You gain insight as to manifold and header flow restriction and design. Manifolds and headers with low flow
coefficients have much potential for flow gains from redesign and porting. Flow restrictions from components
with high flow coefficients indicate the size of the component is more of a restriction than its design.
• Runner Flow Coef has a significant effect on tuning, however this effect is not yet clearly understood. See
Appendix 3.
2.9.8 Calc Taper, deg
Is the Taper angle for either the intake runner in the manifold or the collector of the exhaust header calculated from the
following specs. Taper is defined on
Figure 2.45 Runner Taper
page 28 under Intake System specs
Specs at Runner Entrance
and page 39 under Exhaust System
Runner Specs at Head
or
specs. See page 97 for general notes
or
Specs at Collector Exit
on Calculation Menus and for an
Specs at Entrance (by primaries)
example of their use.
The equation for Taper depends on
the length of the Intake Runner or
Exhaust Collector. This length is
based on the current settings of these
specs in the Intake System or
Exhaust System specs menus and is
displayed in the Notes section at the
bottom of this menu. Make sure this
length matches the runner or
collector for which you are
calculating Taper before using this
menu.
Taper Angle
Runner Length
or
Collector Length
107