initial timing advance

[drew@dyermaker.cs.uoguelph.ca (drew)]

There seem to be two schools of thougyht here - 1) set it to 12* BTDC, or
2) keep it at the stock 6*.

I believe the thinking behind the stock value is that if you set initial
advance to high you'll get pinging earlier in the knock box ignition
advance curve because total advance is higher than the ignition map is
accounting for.  The box will then retard timing by 5 degrees or more to
beat the knock, robbing the engine of power in the process.  By leaving it
at the stock setting, you will be reaching the maximum advance that a
clean, carbon-free combustion chamber can handle on good quality pump gas
(or airplane gas if you live in Ohio - sorry Daun... :) )

There may be gains to setting it higher if you run high octane or octane
boosters, but you'd probably have to run some tests to detemrine this, and
it likely would vary based on weather and engine condition etc.

I run mine about 8* or so, and run 87 octane E10 blend year round
(although the car is mainly driven in the winter) with no pinging, and now
that I have a reliable knock box again, no loss in power.

Drew


On Wed, 20 Nov 2002, Kervin wrote:

> How far do most people set their initial timing advance?  I've got a knock 
> sensor with a Audi distributor that has electronic advance.  With my 
> adjustable timing light that has a dial, I have been using 11* with a idle 
> at 900 rpm.  Today I set it at 13* and there is not any pinging.  Should I 
> just advance it until I get pinging under load and back off from there? 
>  Any advantages to lots of initial advance?
> 
> Kervin
> 86 Scirocco 8v 2.0 p&p 4k+80% and lots of other numbers and letters
> 88 GTI 16v Still sitting and it's winter time now
> 00 tt600
> 
> 
> 
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Drew MacPherson - '84 Wolfsburg Edition Scirocco TurboDiesel