Dave Plowman (News) wrote:
The Natural Philosopher wrote:
Not at all. Certainly in my tuning days, the SINGLE most effective way
to increase power in MOST stock engines was to hit the exhaust first.

That's why I said *modern* production cars. Many older ones had extremely
poor manifolds and exhausts.

It seems to me that in many modern production cars the "performance
tuning" has already been done...