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Tech Tuning

How does the Optimizer work?

Installing the HMF Optimizer
The first step when installing the Optimizer is to connect it to a good ground source.  This can be an unpainted part of the chassis, engine, or the negative battery terminal.  Failure to do so can result in damage to the Optimizer.

1. Locate the Fuel Injector(s) which is typically situated on the throttle body or on a fuel rail
2. Unplug the OEM Connector from the Fuel Injector.
3. Connect the Female Optimizer Connector to the Fuel Injector.
4. Connect the Male Optimizer Connector to the OEM Fuel Injection Wire Harness.
5. Repeat for all injectors. The harness on the Optimizer is not injector specific. 
6. Mount the Optimizer in a safe area where you have easy access to it for on site tuning.
7. Route the HMF Optimizer wires so they’re clear of any moving or hot parts. 
(i.e. exhaust system, head pipe, s-bend, oil lines, hydraulic lines, etc.)


What Does the Optimizer Do?
It's an often misconception that a fuel-injected engine will automatically tune itself when an aftermarket part is added.  This is not typically the case.  When adding an aftermarket part that directly affects the engine, retuning or remapping will be required.

Since the vehicle's computer cannot see intake air volume or monitor the oxygen content in the exhaust (on most machines), it does not know additional fuel is needed. That's where the HMF Optimizer will take over. The HMF Optimizer will change the signal to the fuel injector to compensate for added aftermarket parts. It is a piggy-back fuel controller that plugs directly into the vehicle wiring harness and stays connected so long as it is needed. It's small, water-resistant, and mounts just about anywhere. 


What are the Optimizer Modes?
There are 3 modes that will allow you to increase or decrease fuel percentage from the original fuel map. 

Mode 1 - Green: This controls fuel delivery at lower throttle positions and RPM 
Mode 2 - Yellow: This controls fuel delivery at mid-range throttle input and RPM 
Mode 3 - Red: This controls fuel delivery in higher throttle positions and RPM 

There are two (in some cases three) more modes that are often misunderstood.

Mode 4 - Green and Blue typically will control the timing of the green mode or an accelerator pump feature found on select models.  In some cases this mode may be omitted entirely from the map.   
When used as a timing mode: Lower on the number scale will bring in the green mode (and overall fueling changes) sooner.  Higher on the number scale will bring in the green mode later.  
When used as an accelerator pump function: Lower on the number scale will give you less fuel change when you stab the throttle. Higher on the number scale will give you more fuel when you stab the throttle. 
Mode 5 - Yellow and Blue typically controls the timing of your yellow mode. 
Lower on the number scale in this mode will bring your yellow mode in sooner. Higher on the number scale will bring your yellow mode in later. 
Mode 6 - Red and Blue typically control the timing of your red mode. 
Lower on the number scale in this mode will bring your red mode in sooner. Higher on the number scale will bring your red mode in later.

Modes 4-6 should generally be left alone when doing any tuning unless the vehicle is significanly modified and highly customized tuning is required.


Is each Optimizer different?
Yes.  Each and every Optimizer has a different map that's been programmed for that specific machine with our HMF exhaust systems.  After we have completed exhaust development on a new machine, we dyno for horsepower testing and fuel tuning. Air-Fuel ratio (AFR) is measured by a wide band Oxygen sensor placed in the head pipe of the exhaust. If the AFR is rich (too much fuel) or lean (not enough fuel) we use the Optimizer tuning software to build a custom fuel map that meets the needs of the particular model that we are working with. The software lets us add fuel based on RPM, load or, a ratio of both. When it is all said and done, we have an affordable fuel controller with a map created specifically for the vehicle we are working with. The problem is no two engines are the same, and most of the time you aren't going to stop with an exhaust.


What about other modifications?
You will likely add a free-flowing air filter, maybe a cam, big bore kit, porting, etc. All of these can change the fuel demand. That's why we leave users the ability to make tweaks to the fuel map. The best way to be sure your Optimizer is set perfect for your individual machine is with a wideband oxygen sensor. If you do not have access or are not familiar with this equipment or other tuning methods, it is best to take your machine to an experienced tuner.  Improper tuning will not only lead to less than ideal performance, but can also lead to engine damage.  


If you encounter a drivability problem like a stumble, pop, or misfire, take a look at the Optimizer display when the problem occurs. If the lights are yellow when the problem occurs, try making an adjustment to the yellow mode and see if the problem goes away. If the lights are red when the problem occurs, try making an adjustment to the red mode and see if the problem goes away. 

  • Make all mode adjustments with the engine idling.
  • To increase fuel for any of these modes push the plus button. (While in that particular mode) The L.E.D. lights will move to higher numbers.
  • To decrease fuel, push the minus button. The L.E.D. lights will move to lower numbers.


What does it mean when 1 and 8 are flashing green/red alternately? 
This simply means the Optimizer is receiving power, but no fuel is being added over the stock fuel map (if the engine is currently running). It is common to see this with the key on and engine off, or during off-throttle deceleration. 

Posted Monday, July 22, 2019


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