Engine Speed Limiter Setup

Engine Speed Limiter Setup

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Cut Pattern

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Select the cut pattern type

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0: Random Pattern 1

1: Random Pattern 2

2: Sequential Pattern 1

3: Sequential Pattern 2

Ign Retard Mode

Applies the Ignition Retard as either an Offset or Percentage of Base Angle (Table value)

Example: Current Ignition Angle = 25.0 BTDC

Offset = 15.0 Deg Retard.  Ignition Angle During 

Limiting = 25.0 - 15.0 = 10.0 Deg  BTDC

Percentage = 50.0 % Retard. 

Ignition Base Angle = 20.0 Deg.

Ignition Angle During  Limiting = 20 - 50% x 20.0 = 10.0 Deg BTDC

(assuming no other Ignition trims)

Control Range

Control Range (-/+) RPM Units

The Control Range applies to the Min/Max % Cut values

Example :     

Min % Cut Clamp 10%

Max % Cut Clamp 90%

Control Range -200rpm

RPM Limit 7000rpm 

At 6800rpm the engine will begin its cut routine at the Min % Cut Clamp of 10%

At 7000rpm the engine will finish its cut routine at the Max % Cut Clamp of 90% 

Minimum %Cut Clamp

Percentage cut applied to the engine at the start of the control range.

Maximum %Cut Clamp

Percentage cut applied to the engine at the end of the control range.

NOTE: Maximum Cut MUST be > Minimum Cut

Hard Limit Adder

Used in Limit types 2 and 3.

Added to the start on the limit and determines the point at which a 100% cut will be applied.

Example:

Limit Type = 2 (Fuel Cut + Ign Hard Cut)

RPM Limit = 7000

Control Range = -200 RPM

Hard Limit Adder = 180 RPM

Fuel %cut Engine Limiting starts at 6800 at the Minimum %Cut

Fuel %cut Engine Limiting ends at 7000 at the Maximum %Cut

Ign 100% cut occurs at 6980 RPM and above.

dRPM Gain

Compensates for a fast rate of change in engine speed by reducing the limit value.  

Used to prevent the engine  pushing through the limit.

Locked out when  dRPM < 2000 RPM/sec.

A Gain of 100 will reduce the limit by 100 RPM for every dRPM 1000 RPM/sec over the 2000 start threshold.

Example 1:

dRPM Gain = 100

RPM limit = 6500

dRPM = 3000 RPM/sec

New RPM Limit = 6500 - 100 = 6400

Example 2:

dRPM Gain = 100

RPM limit = 6500

dRPM = 4000 RPM/sec

New RPM Limit = 6500 - 200 = 6300

0 = OFF

Ignition Retard

The amount of Ignition Retard applied during limiting.

There are 2 modes :

 - Offset (Deg)

-  Percentage (%)

Post Start Lockout

Will prevent the limit operating during crank and for a time after the engine has started.

Useful when channels like oil pressure are assigned to an RPM limiter function.

** Using the Engine Protection Control function is highly recommended instead