| 00:00 |
- Now that we understand what EFI is, the next obvious question might be, why do we need to make adjustments to our tune in the first place? The answer really depends on what you're driving and what you're trying to achieve, and in some cases, the answer may be, you don't.
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| 00:20 |
Let's say you've got a stock standard road car that's running the factory-fitted engine management, and everything's running just fine.
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| 00:28 |
Obviously there's no actual need in this situation to make any changes, but since you've got this far, then chances are, you've got a desire to improve performance and engine power, and I can relate to that.
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| 00:41 |
When the factory engineers develop the calibration for the engine management system in a new vehicle, their aims aren't going to be the same as ours.
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| 00:51 |
Their main aim is to always ensure the engine meets emission standards.
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| 00:57 |
Beyond that, they also need to consider that the same vehicle might be sold to several different markets around the world.
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| 01:04 |
It may operate on a range of fuel octanes and be expected to perform under a wide range of climates, from extreme cold to extreme heat.
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| 01:15 |
This requires a level of safety to be built into the factory calibration, that often leaves some potential for power and torque on the table.
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| 01:26 |
In the aftermarket, we can often take advantage of this, by optimising the tune to suit our exact operating conditions, as well as the specific fuel we're running the car on.
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| 01:39 |
The results can be quite variable, but it's not uncommon to see gains of 10% or more in power, without adding any hardware modifications.
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| 01:50 |
Conversely, there are some cars on the market where the calibration, along with an ECU that is self-learning, can mean that there is little to no gains to be had, unless you're prepared to make some hardware changes too.
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| 02:04 |
One of the best examples where aftermarket tuning can pay huge dividends, is in the situation where the manufacturer has several models in their lineup that share the same basic engine package.
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| 02:17 |
Often the manufacturer will differentiate between a cheaper base model and a more expensive premium model, by providing the premium model with more engine power.
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| 02:28 |
This can be done by purposely de-tuning the base model, and in the aftermarket, we can right those wrongs, often with impressive results, and a minimal outlay of both time and money.
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| 02:41 |
Of course, the real benefit of aftermarket tuning is realised when we begin making hardware changes to our engine.
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| 02:49 |
I'm talking here, for example, about changes such as adding a new exhaust system, aftermarket headers, and a better flowing intake.
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| 02:58 |
Alternatively, more extreme changes could be made, such as porting the cylinder heads and fitting a more aggressive cam.
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| 03:06 |
Lastly, we could also go ahead and fit a turbo or super-charger to an engine that was originally naturally aspirated.
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| 03:14 |
In any of these situations, we're significantly altering the amount of air flowing through the engine, and hence, we're going to need to adjust our tuning parameters to ensure that we're still supplying the right amount of fuel, and igniting it at the right time.
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| 03:31 |
Failing to adjust our tuning to suit these kinds of modifications could result in us leaving potential power untapped, or it may result in the possibility of engine damage.
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| 03:43 |
The more serious and extreme the modifications we perform, the more likely we're going to need to alter the tuning parameters to keep our engine running happily.
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| 03:53 |
For example, if you were to simply fit a cat back exhaust to an otherwise standard vehicle, chances are, the car will still run adequately on the stock tune.
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| 04:04 |
Try fitting a turbo to a naturally aspirated engine though, and it's going to be a very different story.
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| 04:11 |
Now we know why we might want to make tuning changes, we can move on and look at how we can actually achieve this, in the next section.
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