PN2950 Datasheet, PDF (16/24 Pages) Mallory performance club – Atomic LS EFI Master Kit LS2/LS3

16
INSTALLATION INSTRUCTIONS
A/F Targets: The Atomic LS provides an option to set an air/fuel
target for Idle, Part Throttle, Wide Open (WOT), Boost and
an Auxiliary setting. The Atomic will use its self-learning
technology to adjust the fuel delivery to meet the target air/
fuel ratio. The values are adjusted in 0.1 increments and
range from rich at 10:1 to dead lean at 16:1. The ideal air/fuel
ratio for cruising is called stoichiometric and is commonly
referred as a 14.7:1 air/fuel ratio.
Boost: The Atomic will switch to the commanded boost
A/F ratio once the manifold pressure reaches
110Kpa (approximately 16 psia - 32.5in/Hg)
(Figure 21).
Ignition Timing: The Atomic provides a base timing table for each
engine application. These values can also be modified to
compensate for CARB approved accessories. Each setting
is adjustable +/-10°. Note that the values programmed
are set for stock engines using 91 octane fuel. For lower
octane fuels it is recommended to retard the timing 5° as
a starting point. Timing can be retarded up to 20° in 0.1°
increments. Note that in order to alter the timing for auxiliary
use, the Auxiliary Selection in the Advanced menu MUST be
programmed to ENABLE. When 12 volts are applied to the
Brown/White wire (Pin C), the timing will retard (Figure 21).
TPS Enrichment: To assist in throttle transitions the Atomic EFI has
a feature to increase fuel delivery by a prescribed percentage
any time there is an increase in throttle position. If needed,
make small changes in no more than 5% increments without
further testing. Most engines will find 25% sufficient. Most
applications will accept 15%-35% enrichment. Adjustable
from 0-100% in 1% increments (Figure 21).
MAP Enrichment: To assist in manifold pressure transitions the
Atomic EFI offers a MAP enrichment feature. This function
adds fuel based on MAP transitions while moving the throttle.
Large cam vehicles with low vacuum generally required a
slightly smaller number while stock/small camshaft vehicles
with a high vacuum may require more. If needed make small
changes of no more than 5% increments without further
testing, 25% is sufficient for most engines but between 15-
35% is normal. Typically, the higher the vacuum the higher
the percentage needed. Adjustable from 0-100% in 1%
increments (Figure 21).
2-Step: This setting will rev-limit the engine at the programmed RPM
when the Blue wire is activated with 12V. The 2-Step setting
is used in drag racing applications to help launch the car at
a consistant RPM. The blue wire is normally connected to a
clutch switch or a brake switch. The default setting is 10,000
RPM and can be adjusted from 1000 RPM to 7500 RPM in
25 RPM increments (Figure 21). The ignition cut should only
be used on race vehicles with a very free flowing exhaust.
DO NOT use with catalytic converters or severe damage
may result!
A/F Targets
Igniton Timing
TPS Enrichment
MAP Enrichment Setting
2-Step RPM Limit
Figure 21
M S D  •  WWW.ATOMICEFI.COM • [phone] • FAX [phone]