On Mon, 18 Feb 2008 04:46:09 +0000, Lanny Chambers wrote:
> In article <Xns9A47B6DE9D647xs11emailinatorcom@[EMAIL PROTECTED]
>,
> XS11E <xs11e@[EMAIL PROTECTED]
> wrote:
>
>> Only if the knock sensor detects "pinging", otherwise the timing will
>> remain the same as it would with premium gasoline.
>
> I'm not sure exactly how the NC's knock sensor functions,
I would assume it listens for the characteristic sound frequencies
like others?
> but such
> devices typically retard timing FAR more than necessary at the first
> ping, and don't recover quickly.
I do not know about that. The point is that if you discover unacceptable
knock, you already have red-hot carbon deposits on your solid surfaces.
The device *must* retard the ignition much more than would be needed
if it was advanced earlier to prevent knock and the resulting red-hot
deposits in the first place. And the device must stick to retarding
large amounts until they are cooled down enough.
> It's not an efficient way to control
> the ignition on a routine basis, it's an emergency safeguard to prevent
> engine damage.
I would agree completely there. But I would think designing optimized
controls against knock is complicated by the fact that these devices have
no clue about how big carbon build-ups are in the engine. And how bad
their geometry is. And the equation is further complicated by the fact
that a moderate amount of knock is perfectly acceptable.
I would guess Mazda would take the conservative view and assume that
people may have squeezed a piece of coal in their cylinders.
> I wonder if it throws an OBDII code?
I would hope it would at least make a note if the maximum retard did not
manage to get knock within acceptable parameters, but I do not know.
Leon
--
Leon :) Bess :) Bozo .)
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