Friday, January 27, 2012

Modification Harmony (Yin and Yang)


I've talked about whether or not to boost in a previous post and perhaps I might elaborate on the consequences and compensations of modifications.

A lot of people think that modifying a car from it's original design (without compensating its effects) will always better for the car. I believe this isn't the case.

For each modification, you usually need to compensate it with one or more compensating factors.

Think of the original design as the balanced model. Yin and Yang. Adding or removing something to the car changes its balance, slightly or significantly. You then apply some sort of compensating factor to harmonise the entire system to a new balance model. When I talk about balance, I mean the balance of all the subsystems that make up the car from tires, brakes, suspension, chassis and power train. Changes in one subsystem, affects the entire system.

When a modification is applied and actually brings about a better balanced model (without any compensation) means the original system was not balanced in the first place. Here, a compensating factor (or modification) is applied to return system harmony.

Let's take the air intake as a typical example.

If you remove your existing air-box paper filter intake and replace it with an aftermarket pod filter it seems you are doing good to your engine as you've removed most of the restriction. In some cases this is correct but what if the original design was already good enough and there was no restriction in the first place? LOL no gain! (but its still balanced).


Here are few other things that may affect your car's performance when changing your air filter:
  • Power Band: if your car was restricted, removing the restriction should give you more power. But sometimes the power is not distributed evenly throughout the full power band. This may affect your driving style.
  • Placement: if your aftermarket filter is poorly placed, it maybe sucking up hot air from under the bonnet. Hotter air reduces engine performance as air is less dense.
  • Tune: in most cases, changing your air-filter will change the tune of your car's computer. Most drivers won't notice this as computers these days are quite intelligent and "trim" out the difference. But in a lot of cases, especially for boosted cars, changing your air-filter may give it a leaner condition as more air is allowed to be compressed by the turbo/supercharger. Leaving it like this may be fine if the computer adjusts for the additional air, but if not, the higher temps caused by the lean condition can reduce your engine life.

To battle these consequences you'll need to compensate!

  • Power Band: you can re-tune your computer (if you are able to) to adjust the power band to suit your driving style, if you cannot re-tune your computer, you can just adjust your driving style and explore the new power band and find what works for you.
  • Placement: moving your air filter to a more appropriate position or even adding ducting to direct fresh air to the air filter helps compensate the modification.
  • Tune: Re-tune! Retuning can help balance those lean spots and can even make you more power as some rich spots can be tuned. Re-tuning harmonises your Ying and Yang.

The little analysis above is only for the air-filter. Think about what happens when you add boost.. or even change the springs on your car!

Each modification has its consequences and for each consequence comes one or more compensating factors!

So keep this in mind when bringing your car to its new and exciting balanced model!


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