Randall says:
"....Which points out what may be a downside to some people ... running a
lightweight flywheel does make the engine a lot rougher under power at very
low rpm, making the car at least somewhat harder to launch from a stop.
It's still not particularly difficult, but you can no longer just take your
foot off the clutch and know it won't stall.
In perhaps 15 years of driving my TR3A to work in traffic almost every day,
I killed the engine maybe twice with the stock 30+ pound flywheel. After
installing a 14# aluminum, I killed it probably 6 times in the next month.
Now you're free to think that's my poor driving skills ... perhaps it is.
But I've driven manual transmissions all my life, and I've never had one
that was quite as hard to launch smoothly at low rpm as my TR3A was after
installing an aluminum flywheel.
Still, like Joe says, the transformation is amazing ... my next TR3 will
definitely have a lightened flywheel.
Randall"
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Randall and the List
I agree with Randall. My experience with a 10# flywheel is limited to track
time. I would suggest that 19#-21# would be more ideal for a street car. (I DID
say reasonably lightened flywheel)
The reason for a 31# in a TR is a bit lost to history, but there seems to be
no good reason for 31# when 21#s will do, make a significant impact on
performance. "Gene" in Phoenix reported to me that he took only 5# off of the
periphery and the results were astounding to him.
I have lightened flywheels to 17-19# (without the ring gear) to a blueprint,
and have no concerns with the TR3/TR4 flywheel. Kastner took the stock
flywheels a step further to 14#, but that is another story, and not mine to
tell.
Jack Drews took the process of lightening to the ring gear and took another
couple of lbs off, not much, but it is all at the extreme periphery. Many of us
run
Uncle Jack's Ring Gears.
All that being said, I am convinced that there is not a single other thing
that will give you the biggest bang for buck in TR3/TR4 performance. Oh
yes...reducing that rotational mass has an impact on braking, too.
Thanks,
Joe (A)
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