Lightweight flywheels on turbo cars

[George Roffe]

Terry Heick, Modern Sports Car wrote:

>Which brings me to a question I often have: take a turbo car and do a roll
>on in first gear -it runs out of revs because of the gearing before the
>turbo can really start making some boost. This being the case, are
>lightweight flywheels really a good idea for a turbo car -wouldn't it like
>the load a stock flywheel provides, and to not keep form outrevving the
>turbo?

Terry, I can't tell you that I know the answer definitively, but....

What is your goal?

Fastest acceleration or full boost?

In theory, a low mass flywheel will allow the engine to rev faster
(especially off-boost with a low compression engine) which in turn will get
you into the boost quicker.  You may not see full boost by the time you
shift out of first, but I strongly think you will get out of first faster.

What I *can* say is that my SR20DET is so smooth there is little
perceptible turbo lag.  It almost feels like my killer NA engine except
when nailing the throttle at about 2k rpm.  Then the engine takes some time
to build boost.

Interesting discussion, but I still think I would lean towards low mass
components.

George Roffe
Houston, TX
91 SE-R (well modded)
91 G20 turbo (well modded)
84 944 SCCA ITS race car under construction
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