RE: flywheel improvement (and balancing)

["Bergman, Micke" <M.Bergman@domain.elided>]

Speaking of Alfa flywheels some basics should be considered.

a) Engine type (inline 4 / V6)
b) Gearbox front (i.e. 105) or rear (i.e. 116) (skipping FWD since I don't
know a squat about them)

The inline engine's flywheel can be balanced separately without any problem.
For the V6, I would balance it with the crankshaft. I don't have any
experience in these yet though.

The transaxle cars have a big problem with too much inertia in the
crankshaft/front flywheel/Propeller shaft/rear flywheel+Clutch assy.

I calculated the power consumption for accelerating the rotating parts of a
standard Alfetta GTV. The following percentages are rotating/total
consumption in different gears:
1	2	3	4
22%	11%	6%	3%

For tuning, I recommend making every part as light as you can. I revolved
the front flywheel to 5 kg (original 8 to 10 kg) and the rear one (one disk
clutch) from 7.5 to 4.7 kg.

With this modification you can still let your grandmother drive the car and
there's no disadvantage at all.

The improvement in acceleration is 13% in 1st gear!! (6% in 2nd, etc.)

The front gearbox models have much less inertia to begin with as they only
have one flywheel. There is no immediate need to tear the car apart just for
this if you're not removing the flywheel anyway.

Personally I would (and did) make it as light as possible without risking
that it breaks.

The crankshaft (2.0) is so heavy that with my 2 kg lightened flywheel I
don't have any problem of stalling the engine.


BTW! As it is my next project. Does anybody have experience in lightening
the crankshaft of a 2.0 Alfa engine?


Micke

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