5.3 Ignition settings 5 SETTING UP A BASIC CONFIGURATION
• Missing Teeth - the number of missing teeth. Common are 1 for 36-1, or 2 for 60-2 or 36-2
• Tooth #1 angle - definition depends on whether main wheel is missing or non-missing type. See sections
below.
• Main wheel speed - indicates whether the main wheel rotate at crankshaft speed or camshaft (distributor)
speed.
• Second trigger active on - Like ignition input capture above, specifies which voltage level is considered
"active"
• Level for phase 1 - only applies in "Poll level" mode. See Dual+Missing section.
• Check at tooth # - Determines which tooth on the crank trigger is used for polling. See Dual+Missing section.
• and every rotation of - how often are second trigger input pulses received. See Dual Wheel section
There are two main categories of install - Existing and Retrofit.
5.3.4.4 Existing In this cases where you are fitting MS3Pro to an engine already fitted with a trigger wheel,
your main task is to wire up the sensor(s), determine the tooth #1 angle and wire up your coil(s). It should not
normally be necessary to alter the engine.
5.3.4.5 Retrofit If you have an engine that did not originally come equipped with a trigger wheel (e.g. a distribu-
tor based, pre-EFI engine) then you have to mount a wheel and sensor and set the phasing correctly. For a typical
car engine - go for a 36-1 wheel on the crank for non-sequential. or a 36-1 wheel on the crank and a 50/50 cam
tooth with gear-tooth hall sensor for full sequential 60-2 works great on most engines too, but is not advised for
very high rpm. For very high revving engines (such as motorcycle engines) due to the number of teeth per second,
36-1, 24-1 or 12-1 are preferred.
While the code can cope with any sensor/tooth phasing, during cranking the rpm will vary up and down greatly
as the engine rotates. It is desirable to place the missing tooth such that it passes the sensor when the engine is
somewhat stable. The OEMs have found that certain tooth #1 angles work well and it is worth following their lead.
It is suggested to align your wheel and sensor to arrive at the following tooth #1 angles. (See later for explana-
tion of tooth #1.)
• 4 cylinders ~90-120°
• 6 cylinders ~50°
• 8 cylinders ~40°
Mounting the wheel is quite critical in that it MUST be mounted so it rotates without moving up, down, left or right,
as the sensor needs to see all of the teeth with a gap of 0.75 - 1.0mm. In other words, keep the runout to a
minimum. It is also critical that the bracket is sturdy enough not to vibrate. When in doubt, make the bracket strong
enough that you could lift the engine with it.
Having mounted the wheel and sensor, you can proceed for an existing install.
5.3.4.6 Missing tooth crank wheel This is a very common configuration for wasted spark with the most typical
wheels being 36-1 (Ford) and 60-2 (Bosch.) Note that the missing teeth are in a single group - if your wheel has
multiple groups then you need a special wheel decoder. We have special decoders for many of the multiple-gap
trigger wheels, such as Chrysler’s NGC or Subaru’s 36-2-2-2 wheels. If you have one of these wheels, see the
spark mode sections be
The MS3Pro code benefits from a reasonable number of teeth (hence 36 or 60) for best ignition timing accuracy.
Low tooth count wheels such as 4-1 are not advised.
Make sure you understand the definition we’re using of tooth #1. With the engine rotating in the normal direction,
tooth #1 is the first tooth to pass the sensor after the missing tooth gap.
AMP EFI MS3Pro manual version 1.202, firmware 1.5.0, 4/21/2017 Page 66
To Next Page
Loading...