The term "backfire" describes the phenomenon in which the fuel burns in a different area than the combustion chamber of the engine. While this is an action you should generally avoid, the explosion in the exhaust or intake duct has a rather impressive effect. The car will look like a monstrous dragster vehicle, with all the smoke and flames coming out of the rear and the engine "roaring"! Remember that backfire can be very dangerous; you should not attempt this maneuver unless you are absolutely sure of what you are doing.
Steps
Method 1 of 2: On Old Models
Step 1. Consider why the machine flashes back
Although it is a relatively easy phenomenon to achieve manually with older cars, it is important to understand its mechanisms and causes. A spark in the wrong place or a sudden supply of fuel or air causes a noisy detonation in the engine. Although modern vehicles are equipped with systems that regulate these factors through the engine control unit, older ones (produced roughly before 1990) are more manageable.
It is important to remember the reasons why these regulation systems are installed. Excessive backfire causes a lot of damage to the car and eventually inevitably leads to the replacement of several components
Step 2. Start the engine
Run it to a constant number of revolutions and set up the machine as you usually would. In this case, normal safety checks (including oil leaks) are even more important, as you are about to generate an open flame.
You should proceed in an open place, relatively free of flammable objects (including people). Keep a safe distance of about 10m
Step 3. Turn off the engine with your foot on the accelerator pedal
This way, you prepare the car for flashback. Theoretically, you don't have to start moving quickly while starting the vehicle, so keep a gentle pressure.
Step 4. Wait a few seconds and start the engine again
Keep your foot on the gas pedal during this phase and, once the vehicle is turned on, press the accelerator as hard as you can; this sequence should trigger a flashback.
Method 2 of 2: On Modern Models
Step 1. Be aware that the car may already have a flashback
Some modern sports cars intentionally behave this way when they decelerate. Manufacturers allow this phenomenon to give the vehicle a more "bold" and aggressive look. Considering that it is much more difficult to correctly generate a flashback in recent vehicles, you have to take advantage of all the opportunities that already exist. Try to decelerate after reaching a good speed (about 100 km / h) and pay attention if you can hear the sound of this explosion; better yet, ask a friend to observe the tailpipe as you drive and reduce your speed.
Step 2. Prepare the vehicle properly
Modern cars (produced roughly after 1990) need a few more tweaks before they safely emit a flashback. Since there is a control unit that intervenes to avoid this phenomenon, the car chassis is not designed to withstand it; in this case, a more robust exhaust (such as the Tomei Type 80) must be provided to minimize damage to the bodywork.
Step 3. Install a new engine control unit
Depending on the model there should be a port with a programming kit (or something similar) connected to the car, which allows you to directly change the ECU software settings. By resetting the control unit you can change the timing and speed of fuel injection. Unfortunately, this operation is quite expensive and it may be necessary to invest as much as 800-900 euros.
Remember that the changes to be made to the control unit are often specific to certain models; you must therefore do some research before finding the right configuration for your vehicle
Step 4. Enter the ECU program and change the fuel injection speed
This is the tricky part that requires knowing the specifics of the car. You have to define at what number of revolutions you want the engine to start flashing back. If you just want a loud noise and a blaze, choose a number of revolutions at which to stop all the fuel supply; instead set a higher number if you want to emit real flames. It goes without saying that higher doses of fuel are also more dangerous; if you've never tried these tweaks before, you should stick to the less risky ones first.
- Although the specifications vary according to the type of vehicle and engine control unit kit, in general your goal is to change the timing of the injection and cut-off of gasoline in correspondence with the number of revolutions at which you want the engine to be generated. backfire. For example, if you are using a "Flash Tune Kit" programming kit, set the fuel supply to the minimum negative integer that the system accepts. Enter these negative integers (for example -15) for a range of about 200 revolutions per minute; basically, this is the "trick" that triggers the detonation.
- By setting the wrong numbers you could inadvertently destroy the machine; you shouldn't even think about making these changes without the support of an experienced mechanic.
Advice
- Although it has no technical use, the flashback can impress people at a party thanks to its "pyrotechnic" effect. Always make sure the audience is at a safe distance to avoid causing burns!
- If you're looking to get flames out of the exhaust, it's worth stocking up on some fuel. Gasoline flows into the engine more quickly during this maneuver, so you need to consider this if you intend to proceed.
Warnings
- Engines that backfire are extremely noisy, so you should only use them in places where noise pollution is not a problem.
- There is no need to remember that, if you care about the integrity of the engine, it is not advisable to regularly generate a backfire; in modern cars this phenomenon causes serious damage, so proceed with caution.
