16v or 8v turbo?

[Larry" <rocco16v@netzero.com (Larry)]

You know, what you said makes perfect sense.
(Should I be alarmed?)

Larry

> ok, now that requires a slightly different explanation.
>     BMEP is the MEAN pressure, i.e. the average pressure. for this you
have to picture whats going
> on during the combustion process. you cant simply consider the peak
pressure, you must consider the
> pressure maintained during the combustion stroke. after all, the peak
pressure at tdc is doing
> effectively no work at all (picture bicycle pedal at tdc). as the piston
moves downward, the effect
> is a pressure drop (naturally). combustion continues well beyond tdc, so
combustion keeps the
> pressure up, acting against the pressure drop. this results in a large
pressure being maintained 90
> (crank) degrees beyond tdc (pedal parallel to ground). it is that pressure
that is doing the work
> for you, ultimately resulting in high BMEP numbers.
>     now lets go back to the 8v vs 16v stuff. keep in mind i am talking
stock engines (with added
> turbos) in both cases. previously we established that we had to limit peak
pressure (at tdc) by
> using lower boost on the 16v. another aspect of the peak pressure to
consider is that spark occurs
> before tdc, so your calculated peak pressure is actually lower than the
actual peak that the engine
> sees. what this peak is actually accomplishing is detonation, since the
air/fuel has had so much