5000 or 200

[Ken Keith]

On 4 Dec 2001, at 8:12, Eric_R_Kissell at email.whirlpool.com wrote:
>
> Ken wrote:
> [snip]
> >I think the whole "tranny bolt" method of securing the crank when doing
> >the timing belt depends on the presence of the lip that is only
> >on the heavier flywheel.
> [snip]
> >Your sig says you're running a K24 on your '86, which is the low
> >compression MC-1 (1 knock sensor) motor, right?  Did you put that
> >on, or was it already like that?  What can you tell me about the
> >conversion?  I assume it's a feature. :-)  Do you like it?
>
> I have done the "tranny bolt" method on this car, so I guess it is the
> older heavy flywheel. One question I have about the flywheel is that if
> lighter is better, why did they make the flywheel so heavy in the earlier
> cars? Did they want to make sure that the engine felt really smooth or
> what?

I think lighter is more towards the "performance at the expense of
luxury" end of the spectrum.  A lighter flywheel would require the motor
be revved higher to get the car moving (maybe having to slip the clutch
more?), which maybe isn't what they wanted their owners to experience.
 A heavier flywheel makes starting the car from a stop easier.  I believe
it feels like a torquier motor off the line, but revs up and down slower.

The change in the flywheel to use less material is partially made up for
by the redesign of the pressure plate.  As far as net change in total
rotating mass (moment of inertia? read that in the archives), it's not
necessarily lighter by how much less the newer flywheel itself weighs.  I
haven't weighed the pressure plates (or the flywheels), but basically the
newer version replaces the thick steel lip with the much thinner stamped
metal of the pressure plate cover.

> I upgraded the '86 5000cstq with the SJM 1.8 bar boost upgrade using the
> original K26. It was nice, but did not spool soon enough for my liking so I
> went and found a K24 from a 1990 200q in a wrecking yard for $200. This K24
> was a direct bolt-in swap. In my opinion swapping the turbo was not very
> hard at all. Much easier than a timing belt. The car now feels much better
> at lower rpm. I now see 1.4 bar on the dash by 2000rpm and I can see 1.8
> bar by 2500rpm.

Cool, kind of like the low rpm grunt of the 1.8t setup?  I'm sure some
opine that running a K24 at those higher boost pressures pushes it
towards the edge of it's efficiency.  Does it seem to keep up at higher
rpms?  How does the high rpm performance compare between the K26
and K24?

Thanks,

Ken