> Just curious... Is the lack of backpressure a problem? Or does the
> cat create enough backpressure? I'm not sure about 4 stroke engines
> but on 2 strokes, a tuned exaust is a very important part of the
> system. The back pressure pulses work together with the engine
> for the most power. A little more backpressure or a little less
> backpressure would result in less HP.
>
> Is this the same for the Dak, or is this a whole 'nother animal?
>
> (And isn't popping and backfiring a problem without enough backpressure?)
>
>
> -Jon-
Jon:
Yes, too little backpressure is a bad thing. The exhaust system on
any vehicle is very importand to the performance of the engine. Why?
Well, it removes the burnt gases from the combustion chamber and
helps pull in the fresh charge. As the exhaust charge moves down the
tailpipe, it has momentum. When the exhaust valve opens, the
momentum of the gas that is already downstream "pulls" the gases out
of the combustion chamber and even helps to pull in fresh fuel and
air to burn.
I've also heard the term "overscavenging" used in these discussions.
It's possible that fresh fuel and air actually get pulled out the
exhaust valve when the cylinder is trying to purge itself of old air
and fill itself with new air.
Or so I've heard... ;^)
=Scott Vieth http://www.msn.fullfeed.com/~scottv
'68 Camaro RS, 327/PG
'97 Dakota Sport 4x4 Club Cab, Magnum V8/5-spd, Gibson cat-back, FIPK-clone
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:38 EDT