- Joined
- Dec 8, 2011
- Points
- 145
100% agree with you.I am no fan of "bolt on" performance parts in general. All cars are manufactured as design compromises, mostly between cost, performance, economy and usability/comfort. Much is invested by the manufacturer to get this right for the "standard customer", whoever he or she is. You may improve one aspect whilst degrading another with "enhancements" which is fine as long as the likely outcome is considered and acceptable. The aftermarket air filter is a good example: you pays money for it (the aftermarket supplier is happy), likely the noise increases (some may like this, some may not) and quite possibly performance/economy decreases (likely not enough to notice and the placebo effect might kick in). There is real possibility that the design is compromised and the real time and long term reliability thereby impacted.
I can fully understand engine tuning for a track/race car where performance and safety are paramount but for road cars I would urge caution.
That said, I am considering lowering springs and new shocks for the Z3 (and replacing all suspension bushes with OEM). Possibly also H&R stiffer antiroll bars. I know that this will cost circa £1K, I will get a firmer ride (less comfort), the car will look better (I hope) and allow the car to out handle bigger engined cars on track
Just some thoughts!
In my opinion, most of the restrictions in the inlet and exhaust are for sound suppression. For legal reasons and to satisfy the majority of prospective buyers of the NEW car, BMW need to make the car a nice place to be. Most NEW buyers who were parting with £40k+ in 1998 would not be happy with a car that was too noisy and would rattle the showroom windows.
Most modifications to the inlet and exhaust are an attempt to increase airflow. Most of these modifications would make the car too noisy for BMW to sell to the maximum number of punters.
Some inlet modifications create more noise by restricting the airflow. This is because of what I call the "syringe effect". This is where the engine is trying to pull air into the engine faster than it can flow. It sounds impressive, but is actually very inefficient.
As @t-tony said, there are lots of videos on Youtube showing rolling road evidence that "performance" inlets are a poor investment for performance, but they can sound good.
