Re: So Slow

[Luis Marques <marques@rtis.ray.com>]

All I have to add about the Franco Cam Sprocket on top of what Alex
Kowalski and Gary Erickson said is "ditto".

The Franco "variable cam sprocket" does use a system of centrifugal
weights and springs to change the cam timing as a function of RPM, very
much like the centrifugal advance of the ignition distributor on N/A
cars.

Unfortunately, while the distributor is trying to advance the ignition
timing, the Franco sprocket is retarding the camshaft (and distributor)
so the net effect is that you don't gain anything on the top end.  I
guess you could gain some at the lower end, but you can achieve almost
the same results just by advancing the cam timing using a "fixed"
adjustable cam sprocket and you still end up with no top end.  So the
only options are to either not use it, or retrofit some kind of crank
triggered ignition system ($$).  It should work great on turbo cars
though.

I have read that some race teams (I think it was Toyota) have different
ignition maps for different gears and I think that the reasoning was
that more advanced ignition maps give better acceleration in lower
gears, but rob some power at high speed.  So the maps for, say 1st, 2nd,
and 3rd gears are more advanced, while the other gears use a less
aggressive timing map for greater speed on the straights.  Anyone else
heard of this or care to comment?

Luis Marques
'87 4kcsq