Monster Products :: The Masters of Off Road Fuel Injections

What's the difference between the Tune Monster and a fuel controller / programmer?
A fuel controller or programmer is an electronic device that connects between the stock ECM and the fuel injectors. This device interrupts the fuel injector (pulse) signal from the stock ECM. It then looks up the programmed user changes and re pulses the injector by a percentage for a longer (and iwith some devices) a shorter period. This adds or subtracts fuel over the stock ECM. These basic systems rely on the stock ECM and its incoming signal to work. The downfalls are that they delay the fuel injection event to the engine. (Fuel injects when the valves, cam and piston are at a different spot than what the stock ECM, OEM and engineers intended. This cannot be controlled and optimum tuning cannot be achieved. The problem is also more pronounced when longer duration camshafts are installed. Another problem is the stock ECM base injector pulse is always changing and these units can only correct the same programmed percentage amount. So, they can work in constant situations but when the ambient air temperature or elevation changes- they need to be readjusted. When the load on the engine changes (high range to low range or a manual transmission - they cannot adapt to each gear. (Some companies have "tried" ways to accommodate this by having different fuel maps per gear selection) Some devices can only adjust both cylinders by the same correction, they cannot tune both cylinders individually.

The Tune Monster ECM is much more powerful. It has the capability to control the entire engine. It fully replaces the stock ECM's control by it's own control. ECM's can be stand alone or in some circumstances be used to work with the stock ECM if there would be an advantage. Our ECM works the same as the stock ECM and will modify the fuel with temperature and altitude changes. They also do not correct the stock ECM, but takes over and directly controls the injectors. They use the actual sensor inputs to measure and calculate the actual amount of air entering the cylinders. As well as control all the other functions like rev limit, cooling fan, ignition timing, start up fuel, warm up enrichment's (like a carburetor choke).

What is injection timing or fuel injector timing?
Injector timing is the relation between when a fuel injector puts fuel into the engine compared to the exact position of the piston and valves.

How does the injector timing affect the engine?
Fuel needs to be injected at the optimum time to achieve the best power, best fuel economy and best engine longevity. We actually use the fuel timing as another tuning parameter to optimize over the stock ECM settings. Example- the stock injector timing is set for stock cams which open the valves at a certain piston position. When longer duration cams are installed, the stock ECM now injects the fuel too late. Then adding a device that delay's the injection makes the problem even worse. An ECM will inject fuel even sooner. This will provide the best power and atomization of the fuel.

How does the Tune Monster differ from a fuel controller regarding atmospheric air temperature changes?
The stock ECM uses corrections that are applied to the main fuel tables when it encounters different altitudes. The pulse to the injector is then modified. When a fuel controller / programmer is used, this means that the input injector pulse that it reads is changing. And then the user entered device corrections do not work anymore and retuning is required. This problem is there regardless if the device uses throttle mapping or pulse width mapping. The Tune Monster acts the same way as the stock ECM. Except that it is fully user configurable. The main fuel tables are tuned in to your main environment. Then when you encounter different elevations, there is user table entries to apply any amount of correction that you want for each variable. This equals perfect tuning all the time.

How does the Tune Monster differ from using a fuel controller regarding elevation or altitude changes?
The stock ECM uses corrections that are applied to the main fuel tables when it encounters different air temperatures. The pulse to the injector is then modified. When a fuel controller / programmer is used, this means that the input injector pulse that it reads is changing. And then the user entered device corrections do not work anymore and retuning is required. This problem is there regardless if the device uses throttle mapping or pulse width mapping. The Tune Monster acts the same way as the stock ECM. Except that it is fully user configurable. The main fuel tables are tuned in to your main environment. Then when you encounter different temperatures, there is user table entries to apply any amount of correction that you want for each variable. This equals perfect tuning all the time.

What is the effect of the fuel/engine during elevation changes?
Contrary to popular belief, an engine requires more fuel as altitude increases (for the same given air pressure).

The misconception is that as air pressure decreases, less fuel is needed. This is true, and why carburetors need the jetting leaned out. But this is only part of what is going on. An air pressure of 80kPa at sea level requires less fuel than the same 80kPa air pressure at 10 000 ft. Why ??? Because the air is less dense. This reduces the back pressure of the exhaust. Less back pressure means a more efficient engine. (A more efficient air pump). The higher efficiency engine now requires more fuel (for the same given air pressure). The ambient pressure drop vs. decreased fuel is automatically done in the fuel table with the Tune Monster. (Lower pressure automatically receives less fuel because the ECM calculates fuel based on real engine load / air pressure). The Tune Monster fuel tables use the MAP sensor readings as part of the tables. The addition fuel correction is set by the user to their exact machine and requirements. Perfect tuning, all the time.

Can I make full throttle starts if I want to?
Absolutely. There is an easy setting that allows you to do this.

Why is the stock ECM still used?
The stock ECM is left in service to control the dash / operators display, power steering, air suspension and the key security system.

Will the Tune Monster make my engine more powerful?
Absolutely. Optimum tuning will extract the most power possible out of any engine combination. Just as proper and improper clutch setup will have a dramatic effect on your machine. The stock ECM was optimized, or better said " compromised" for fuel economy, emission standards, engine safety, restrictions, using bad fuel, low grade pump fuel, all different temperature climates, all different altitudes, a stock motor and a target hp output. Which one of these is optimized on your particular machine? Was the factory programming done for pure hp? Detuned? Emissions? Fuel Economy? Safety?

Is there any other benefit besides the most power and optimum tuning?
Yes, over coming all of the stock ECM limitations and restrictions. Having a cooler running engine with a lower fan cycle temperature. Access to all sensor data. (live and datalogs)

How long does it take to install the kit on my machine? How long to remove?
Total installation time is only a few minutes. You just connect the supplied harness to your machine. Removing is the exact same.

How long does it take to tune an engine using the Tune Monster?
This can vary quite a bit from user to user. It depends on your tuning background, computer skills, and your ability to read the supplied manuals and documents. There is how to tuning manuals supplied as well.

Normally a couple hours will get you pretty close. Squeezing every drop of power or economy can be more time consuming. Tuning the cold warm-up and cold starts (like an electronic carburetor choke) may take a few days to get perfect, or even redone at a different season. We would definitely recommend setting aside a few days if you are starting from scratch. You must learn the software and ECM operation as you tune along the way. Remember that cold engine starts might be only gotten once or twice per day. Once learned and familiar it doesn't take long at all to dial in some optimum tuning.

Can I use a single cylinder / table tune with the Tune Monster?
Yes. But it's not recommended. Having a 2 cylinder engine with different intake and exhaust tracks will have different fuel requirements per cylinder. Using an ECM is also different than using a correction device. The correction device or fuel controller can use a single table tuning, but these are correcting a dual tuning from the stock ECM. They are just correcting both cylinders the same. The stock ECM still has dual tuning as the base signals. This is another problem / downfall when using a correction device. The Tune Monster should be programmed for each cylinder separately for the best results and engine safety. If you test your engine configuration and both cylinder's fuel requirements are pretty close than by all means, use a single table tuning. But we recommend you check it first.

Can the Tune Monster tune itself?
Yes, there are many ways to tune. The ECM has automatic internal tuning (Self-Tune), tuning from the software using the powerful processor and memory from your laptop (Auto-Tune), there is an option to tune from datalogs (Datalog-Tuning), and there is also a manual tuning software page (Manual-Tuning).

What is Auto-Tune?
Auto-Tune is part of our Tune Monster software program that uses all of the engine sensor inputs and exhaust feedback to automatically tune your fuel tables to your desired Air Fuel Ratio. The software uses the powerful memory and speed of a laptop. It looks at data not available or even thought about and at calculation speeds that far surpass a human trying to manually tune an ECM.

What is Self-Tune?
Self-Tune is a slimmed down version of Auto-Tune that's programmed right into the ECM. No laptop is needed, the ECM tunes the fuel tables all by itself.

What is Manual Tuning?
Manual Tuning is a page in our software that brings up certain gauges and the fuel tables side by side. It also adds keyboard short cuts as well as the computer mouse to change fuel tables.

What is Datalog Tuning?
Datalog Tuning uses a very similar software program as our Auto-Tune but it looks at datalogs instead of live readings. This is part of the datalogging software we use but is not affiliated with us. The software comes supplied, but the tuning option must be purchased through them. (if ever wanted)

What does stoichiometric mean?
Stoichiometric is the ratio of air to fuel in that the mixture is completely burned and nothing is left over. This is 14.7 to 1 AFR. This means a ratio between 1 part of fuel (by mass) to 14.7 parts air (by mass). This is not by volume which is usually mistakenly thought. Stoich creates hot exhaust gases though and IS NOT a safe ratio under wot or load. Additional fuel is added for cooling of the internal engine parts and the exhaust gases. The rule of thumb for straight gasoline has always been to tune for 13:1 AFR at peak torque and 12.5:1 at peak horsepower for a little more additional cooling at the higher rpm because the engine can see this rpm for a longer period when driving. Theses are only a guideline, by all means not necessarily the best for your engine. Lighter engine loads used for cruising can run up to stoich (14.7 15:1) for economy in those cruising zones. Idle usually needs to be richer than stoich to obtain idle smoothness.

Can lean mixtures really destroy my engine?
Yes. Lean mixtures make an engine run hotter. And when too hot will cause the piston or rings to over-expand and then gall into the cylinder causing damage. The idea that lean mixtures at high loads burns holes in pistons is correct, but it is for a different reason than some people think. The exhaust gases are always hot, to different degrees. However, with a lean mixture, there is extra oxygen left over in the combustion products (by the very definition of lean). Combining very hot oxygen with hot aluminum results in the aluminum (the piston) burning. Under pressure, the aluminum chemically combines with the left-over oxygen, just like if it had been hit with an oxy-acetylene gas cutting torch!!! The burning of the aluminum adds further heat, and the process gets catastrophically destructive in a hurry.

Can rich mixtures really destroy my engine?
Yes. Too much fuel washes the oil off the cylinder walls removing the much needed lubrication. Running too rich will overheat the exhaust system. This wears out any packing and accelerates rust. It can also damage or overheat any components around the exhaust.

How can I tell if my engine is rich or lean during acceleration which is too fast or hard to read a wideband sensor?
There are many symptoms that an engine will give you.

Rich Symptoms:
long surge, slow bog, misfires with louder exhaust noise, dull engine sound, reluctant to rev, rpm will drop off while trying to hold a steady rpm, muffled pops in the exhaust, firecracker pops in exhaust (very rich), black smoke from the exhaust, (don't confuse with normal black soot in tailpipe), strong smell, watering eyes and difficult breathing/coughing if in a semi enclosed area, hot exhaust, runs better in high than low or uphills (higher load), performance is flat/ not crisp, condition is worse when hot/ runs better cold

Lean Symptoms:
short continuous surges, tries to rev but can't, misfires with regular exhaust tone, quick bog, pop in intake/ airbox, hot engine, runs better in low range (less load), engine pinging (preignition), acceleration is poor, performance improves slightly when warmed up, will accelerate up to the mid range than pause or stumble

When tuning for fuel economy under light loads, why shouldn't I tune over 15:1 AFR?
Some automobiles might be tuned up to 17:1 in light cruising areas. But there is a reason they can safely do that. Automobiles have an EGR valve system that redirects exhaust gases back into the combustion chamber that effectively dilutes the mixture with inert gases. They can run 17:1 ratio because overall they are getting much less of a fuel / air mixture into the chamber. This drastically lowers the explosion, power output, and heat created. This is a very different application.

Does using 10% ethanol gas have an effect?
Yes it does. Both on power and air fuel ratio. When using fuel with 10% ethanol, this changes the wanted AFR ratio a bit. Pure gasoline has a stoichiometric ratio of 14.7:1. (best ratio where all the fuel is burned and there is no additional cooling) When ethanol is added it dilutes the fuel with an extra oxygen molecule and has a lower btu output. (heat content/ power of the fuel). Since straight ethanol has a stoich ratio of 9:1, when mixed in with gas at 10% volume, this changes the stoich ratio to about 14.2:1. So the fuel will make your engine leaner. You need to lower your target ratio by the same percentage. So when using 10% ethanol fuel and you tune to 12.5:1, you will actually be at the same power as 13:1 (or 12.7 to get 13.2:1) with pure gasoline. For basic calculations to use ethanol blend, take 3.5% off of your target ratio used with pure gasoline.

What is a wideband? Do I need one, two?
A wideband sensor (also called oxygen sensor or exhaust sensor) is a sensor that goes into your exhaust pipe and measures the left over oxygen in the gasses after combustion. This will indicate the AFR (air fuel ratio) of the engine. A wideband differs from a narrowband in that it can measure a complete range. Like 10 AFR to 20 AFR. A narrowband sensor can only indicate if it's above or below 14.7 AFR. To accurately determine how an engine is running, a wideband sensor or exhaust temperature sensor must be used. Most dyno's or tuner shops have their own wideband setup and can tune for you. Tuning yourself is the best way because you learn and you can re-tune yourself anytime you do more modifications. (Or run at different elevations or seasonal temperatures).

You can use 1 sensor with our ECM or 2. Having 2 is definitely easier when tuning 2 cylinders. But you can do it fine with 1 sensor and a little more work. Dual cylinder tuning with 1 sensor is easy, but changing the sensor out of each head pipe when hot is not. Waiting for the exhaust to cool down is a little more time consuming.

Why use a wideband? Can I not just read my spark plugs?
No. Reading plugs in an EFI engine is meaningless except for signs of oil burning or that detonation has occurred. You cannot read them for fuel tuning or state of mixture.

It worked well, back in the day of leaded fuel and carburetors. Unleaded fuel leaves black soot, and is a normal combustion by-product. (= doesn't mean a rich mixture if spark plug is black). A carburetor has 3 circuits, and using 3 plug chops (not looking at a used plug but installing a new plug and shutting of engine at a throttle position) you could check the condition at each circuit. (pilot jet, needle jet & main jet). But an EFI engine has tables of 144++ cells. There is no way to check the condition / mixture at all throttle positions and RPMs by looking at a spark plug. Let alone a used spark plug that has been ran for several hours. What cell would you be checking? If you had a rich idle and let it idle before shutting off - it could hide very lean conditions. Or vice versa. Or gas with a lot of additives will show black plugs. Even a wrong plug heat range will give false information. (doesn't burn off or gets too hot). You could have a rich cruise area of the table and a dead lean WOT part. If you spend 80% of your riding cruising or in slow terrain - you will never see the damage that is going to happen when you open it up down a road sometime. You could have a rich warm-up table/ acceleration pump and lean running fuel table - which one is the plug going to read???

Don't even bother trying to read spark plugs for mixture. The only valuable information you can get from plugs, is signs of oil in the chamber or that detonation has occurred. The only way to tune or monitor an EFI engine is with a wideband exhaust sensor.

What is exhaust sensor latency or sensor delay? How does this effect anything?
Often over looked. Every exhaust sensor and controller have a time needed to measure the information, report this to the controller or ECM and then the device or ECM needs to respond. This is the sensor latency. Then there is the delay in which sensor mounting has a huge effect. Most systems don't take this into consideration, but the distance from the piston to the sensor will take a certain amount of time for the exhaust gases to flow. This also changes with RPM. Without taking these 2 critical variables into consideration, the accuracy of sensors or any kind of accurate auto tuning cannot be achieved. We have inputs to set these variables so that the exact engine / exhaust pulse can be matched exactly to the injector pulse that created it. How else can tuning be accurate ???

Why does a wideband Sensor need to have a controller?
A controller is needed to operate the sensor heating element inside the sensor. The sensors need to stay in a specific heat range to operate properly. The controller converts the signal into a 0-5v DC signal that can be read by an ECM or device. As well, the controller sets and memorizes the calibrations. The sensor needs to be calibrated to the outside air (free air) to use as a reference point. All widebands must use a controller.

Can you explain what ignition timing or spark timing is? How does changing it effect the engine?
Sure. It's the ignition or lighting of the fuel and air mixture in the engine combustion chamber to push the piston down and use that energy. And the exact time this occurs in relation to where the piston is.

There are basically two things to consider for spark timing. Controlling and limiting the explosion and the exact time of the peak explosion pressure in relation to the piston position.

Controlling the burn:
You are adjusting when the fuel mixture ignites compared to the piston position. Top dead center (TDC) is when the piston is at the very top of the cylinder. The time of mixture ignition needs to be adjusted because the speed that the flame travels across the piston top changes with rpm, engine load, engine design and fuel used. Once the mixture is ignited, the flame starts to travel and expand outwards from the spark plug. It quickly turns into an explosion as the whole mixture is burned. The explosion (burn speed) must be controlled so its not too instant or violent but a continuous building of pressure. The more a mixture is compressed, the faster it will explode. This is why fuel octane rating, compression ratio (amount the mixture is compressed), and spark timing greatly effect each other. It's all about controlling the burn and limiting the explosion from causing engine damage.

The Timing Window:
As the mixture starts to burn into an explosion, we want the peak explosion pressure to push the piston down the cylinder as close to TDC as we can. This transfers the greatest amount of energy to the piston, crank, and out to the wheels. Ideally, the time at which the mixture should be fully burnt is about 15-20 degrees after top dead center. The period between the spark firing and the complete combustion of the mixture is very short at roughly 2ms on average. Igniting the mixture too early, the flame pressure pushes against the piston as it is still coming up and energy is wasted. If extreme, this turns into spark knock or detonation and very quickly leads to internal engine damage. Igniting the mixture too late, the flame pressure builds while the piston is already moving down in the cylinder. The mixture charge is not compressed as much so peak combustion pressure is much lower and less power output is produced. Igniting the mixture even later can cause engine damage, but at a slower rate and to a lesser degree. (If the flame is ignited too late or is allowed to burn too long from excess fuel, the flame travels out of the cylinder into the exhaust ports and then heats up the exhaust valves, seats, guides, seals, and complete exhaust system. Over time the excess heat will damage these components.)

Spark knock, preigition and detonation:
These terms are often used interchangeably but they are all different, but very closely related. Spark knock happens when the flame is started too early and the piston tilts in the bore at TDC causing it to knock. Detonation happens when the flame travels too fast or the explosion is just too intense and violent causing the piston to rattle in the bore. Preignition is when something other than the spark ignites the fuel (From too much heat or mixture compression). A super heated or glowing part in the chamber like the spark plug electrode, a sharp edge, foreign or loose material that ignites the mixture. (Lean mixtures or previous detonation can damage engine parts and leave pieces of material.) Or the air entering the chamber is too hot or heated too quickly and ignites from being compressed. Compressing the air too much can ignite it, and the hotter the air, the easier it is to ignite. Both spark knock and preignition lead to detonation. Detonation can also cause preignition on the next cycle. (small pieces of engine parts can stay in chamber glowing red and ignite the next mixture coming in). Violent rattling of the piston (detonation) destroys engines very quickly.

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