"nick smith" > wrote in message
...
> Isn't it partly down to enhancing the max power available,

Yes

at the same time as
> reducing the margins of safety

No. Any vehicle at any speed or power can be very safe or very unsafe
depending on how the performance enhancement is achivieved and especially,
how it is used by the driver.

longevity ?

Any time you use anything harder or put more stress on it you should shorten
it's life. However, a properly done mod used used reasonably may in fact
cause less long term wear to an engine than driving a stock engine hard and
neglecting maintenance. It's all a tradeoff and up to the individual to
decide if it's worth it to him. You could probably get 1000 hp out of any
BMW engine but the longevity might be reduced to hours instead of years.
Look at NASCAR engines - they have lots of horsepower but a life of several
hours.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.788 / Virus Database: 533 - Release Date: 11/1/2004