Effects of camshaft timing on turbo spool-up

[Bruce]

16d?.
Let me guess this is just what one gear tooth is.
that is a huge change.
Moving the intake valves closing point that much will have a huge effect on
actual compression ratio.  If moving a cam that far works, I'd suggest
getting a new grind.
6d is the most I've moved a cam (and it ran worse).
Bruce

From: "Camden Lindsay" <cjl169 at hotmail.com>
Subject: Effects of camshaft timing on turbo spool-up
> Hello,
> I'm sorry if this is not EFI enough to be considered on this list.  If you
> feel it is not, please email to me personally....
> I was wondering if anyone could tell me why camshaft timing effects turbo
> spool-up--
> On my audi (83 turbo motor)  peak boost stock occured at appx 4500
> rpm-6000rpm (8-9 psi, manual wastegate... that is, just a spring, not
> electronics..)... I had read on audifans that retarding the cam (maybe i
> have this reversed-- maybe it was crank retard-- but don't remember) would
> cause spool up to be earlier, which i investigated (purchased an
adjustable
> cam gear).  Indeed it did-  by retarding the cam timing 16 degrees or so,
> (which is what they said to try it at first) the peak boost dropped to
about
> 3000 rpm and the high rpm boost dropped significantly (so it was about
even
> with the  3000 rpm boost, which was 5-6 psi)
>
> The main thing i noticed was the wastegate popping ALOT earlier (3k
rpm)...
> so what'd i do...?  Put a stronger spring in!  After that it ran 8-9 psi
> from 3k to 5.8k or so, with a small taper above that.


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