Lifting Stains... and Gains

[Rob Andrews]

That is kinda what I figured.  But is there a such thing as cam that would
give higher lift without more valve overlap?


> -----Original Message-----
> From: JShadzi at aol.com [mailto:JShadzi at aol.com]
> Sent: Monday, January 28, 2002 10:53 AM
> To: randrews at sbcglobal.net; qshipq at aol.com; mlped at qwest.net;
> quattro at audifans.com; 200q20v at audifans.com; s-car-list at yahoogroups.com
> Subject: RE: Lifting Stains... and Gains
>
>
> Rob, in a supercharged application which is getting boost
> from crank speed not exhaust speed, greater overlap will
> cause power loss due to lost boost.  So yes, no need to go to
> a more aggressive cam really unless you are looking to take
> some power off the bottom and add it up top for greater peak power.
>
> In a turbo applicaiton, however, increased overlap isn't
> quite *as* bad of a thing.  Unlike a supercharger where boost
> out the exhaust heads down the exhaust, in a turbo
> application boost heads back through the exh turbine, thus
> creating more boost energy on the intake side.
>
> I'm more of a proponent for agressive overlap (relatively
> speaking) in turbo applications than most since unlike a
> supercharger, a turbo can actually help spool itself up with
> a little overlap.
>
> Javad
>
> > Good conversation fellows...But I have been wondering this now....
> > I run a 2.8 30 v V6.  It is aftermarket supercharged....
> > SOOO....would I gain anything by adding a cam, or would I
> be blowing too
> > much boost out through valve overlap?
>
>