Franco gear

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <199711141322.IAA01709@lemur.dpspps.kodak.com> kavanagh@kodak.com (David Kavanagh staff) writes:

> I was think about this also. I seems like the static distributor timing
> could be reset after installing the Franco gear, and startup would
> be OK. I was just not sure if the change in the hall effect sensor
> position relative to the crank sensors would mess up the computer's ability
> to correct the timing.

Remember - I'm obsessed with turbos and their ECUs.
 
However - it seems that the distributor Hall effect sensor is not used for any 
timing purpose at all.  The flywheel sensors offer much greater precision for 
triggering timing - but the flywheel revolves _TWICE_ per firing cycle against 
the camshaft and distributor's one rotation.
 
I think in some applications the Hall sensor serves only to differentiate a #1 
TDC _firing_stroke_ from a #1 TDC _induction_stroke_.  As far as the flywheel-
based sensors are concerned, these events are indistinguishable - a 'phase' 
signal is required to determine which of the two flywheel pulses within a 
complete cycle is actually the firing stroke.  Once this is done, the ECU can 
disregard the Hall sensor completely.

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club