[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR94.107]

[Page 609]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 94--CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES--
Table of Contents
 
                       Subpart B--Test Procedures
 
Sec. 94.107  Determination of maximum test speed.

    (a) Overview. This section specifies how to determine maximum test 
speed from a lug curve. This maximum test speed is used in Secs. 94.105, 
94.106, and Sec. 94.109 (including the tolerances for engine speed 
specified in Sec. 94.105).
    (b) Generation of lug curve. Prior to beginning emission testing, 
generate maximum measured brakepower versus engine speed data points 
using the applicable method specified in 40 CFR 86.1332. These data 
points form the lug curve. It is not necessary to generate the entire 
lug curve. For the portion of the curve where power increases with 
increasing speed, it is not necessary to generate points with power less 
than 90 percent of the maximum power value. For the portion of the curve 
where power decreases with increasing speed, it is not necessary to 
generate points with power less than 75 percent of the maximum power 
value.
    (c) Normalization of lug curve. (1) Identify the point (power and 
speed) on the lug curve at which maximum power occurs.
    (2) Normalize the power values of the lug curve by dividing them by 
the maximum power value identified in paragraph (b)(1) of this section, 
and multiplying the resulting values by 100.
    (3) Normalize the engine speed values of the lug curve by dividing 
them by the speed at which maximum power occurs, which is identified in 
paragraph (b)(1) of this section, and multiplying the resulting values 
by 100.
    (4) Maximum engine power is located on the normalized lug curve at 
100 percent power and 100 percent speed.
    (d) Determination of maximum test speed. Calculate the maximum test 
speed from the speedfactor analysis described in this paragraph (d).
    (1) For a given combination of engine power and speed (i.e., a given 
power/speed point), the speedfactor is the distance to the normalized 
power/speed point from the zero power, zero speed point. The value of 
the speedfactor is defined as:

[GRAPHIC] [TIFF OMITTED] TR29DE99.005

    (2) Calculate speedfactors for the power/speed data points on the 
lug curve, and determine the maximum value.
    (3) Maximum test speed is the speed at which the maximum value for 
the speedfactor occurs.
    (e) For constant-speed engines, rated speed is the maximum test 
speed.
    (f) For Category 3 engines, manufacturers may choose to set the 
maximum test speed at the maximum in-use engine speed instead of the 
speed specified in Sec. 94.107(d).

[64 FR 73331, Dec. 29, 1999, as amended at 68 FR 9784, Feb. 28, 2003]

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