[urq] Urq, WX, Head Problems, etc.

[Fluhr]

>Are you still running the MAC-02 for timing?  The reason that I ask is 
>that IME, you will need some serious retuning of the ignition maps with 
>increased boost and 8.5:1 compression or you are going to have big 
>detonation problems.


Speaking of which, my urquattro is running again after the
suspension conversion (two-piece struts, cast front control
arms, rear S2 sway bar).  It seems a little sluggish, running
only 5psi @ 3K rpms.   I was goofing with the ignition map a
long time ago, but I last left it at stock timing before I tore
it down for the work.   I did raise the overboost and put on a
zener diode so I can run > 1bar boost pressure.  Currently I
get ~17psi when I crank the spring down.

I'd like to get back to tweaking the ignition timing.  This
map was made for 87 octane, and I always run 93 octane.
There has to be some room for improvement.  I looked at
RDH's old maps and he only went ~2 degrees more advanced
at any timing point.  That seems a little conservative.
Is there any kind of formula that I can use to estimate
what ignition timing should be given a specific boost pressure,
compression ratio, fuel octane, and maybe some other
parameters that affect the result?   I would like to compare
it to the stock map and see if there is any headroom there.

Thanks,
Eric
'82 urq