RE: Switching from the k24 to the k26 on the dual

[ptimmerm@mashtun.JPL.NASA.GOV]

martin wrote,

>The K24 works better on the Ur-q becouse of the low compression ratio.
>A K26 will most likely be an improvement on a higher compression motor 
>in a 200t. It will definetly improve high end power (high flow with 
>high pressure).  And becouse of high compression ratio he will 
>probably not loose any low end.

********

That's an interesting arguement, and certianly runs contrary to
the industry in general and audi in particular.  I'm just not
sure that it is right, however.

A lower compression ratio engine, properly intercooled, will 
have more top end that a high compression ratio engine, if the
turbo is sized up.  Fine, now decrease the size to enhance the low end.
What have you done to the top end?  You have more backpressure on
the hot side, and more heat on the cold side.  These are bad things.

A high compression ratio enginemight be able to spin up a big turbo
more easily, but it will not be able to take full advantage of the
big turbo's top end.  You don't need high pressure AND high flow
for the high compression motor.

The answer may be that neither "non stock" version (hi-C/little-T
or low-C/big-T) may still limited by our stock CIS sytems at the
top end and thus these quibbles are second order effects.

Where does that leave my 82 UrQ with low-C / Big-T and puny CIS?

no wheres ville man!  The worst of all worlds.

paul timmerman (was this a contribution?)