[Diy_efi] Timing Advance Curve?

[Patrick Cahill]

Dave wrote


I am in the USA in Connecticut..
Unfortunately the map is the property of the guy I tuned the engine for..
His
money spent not mine to give away. I can forward your e-mail to him though
and
let him reply directly. Sorry if it was for my car you could have it. The
engine
has TWM throttle bodies and the SCCA required restrictors so I am not sure
how
much there would be to learn anyway. I will comment that this was one of the
most efficient engines I have worked on in along while. The BSFC was
routinely
in 0.38 to 0.36 range. I thought the dyno was broken to be honest but we
checked
the fuel flow meters and they are correct and the correction factors were
all
right as well. The engine seems to like A/F ratios around 13.8 at WOT and
does
not need a lot of timing as well around 32 to 34 at WOT with race fuel ,
C-12
and 13.5/1 CR. You can add more timing but it makes no more power and it did
not
improve response either. The same with the fuel you can fatten it up a bit
and
the power goes down.
Dave

Rod Hiorns wrote:
>
> Hi Dave,
> I hope you won't mind me asking. A buddy & I are just starting tuning on
> our miatas and wonder if you have suitable maps I can compare to see how
> we're doing. My buddy has a 1.6 at up to 12 psi using a MoTeC, and I
> have a lowly stock 1.8, with a MiataLink, shortly to be turbo'd to 10 psi.
> I know all engines are unique, but any info would be really helpful.
> We're in London, UK. Are you anywhere near?
> Cheers,
> Rod


I can back up what Dave said about timing on these things. They are quite
amazing in terms of efficiency and detonation resistance. The Mazda motor
that I referred to in a post from a couple of days ago as being detonation
proof was a 1.6L Miata engine and it is actually the test mule at MoTeC
right here in Melbourne. I have seen it run 40plus deg timing on pump fuel
without pre igniting. As Dave said, it just loses power. I can only put it
down to an excellent cylinder head design as the main factor.

As a consequence of this, they do like to run on the lean side and I
wouldn't bother with anymore than 32deg on any Miata. What MoTeC does your
mate have? If it has the internal logging and lambda upgrades, these can be
an easy way to tune on the run so to speak.

I have a great deal of experience with all MoTeC systems (V8Supercar to F3)
and would be happy to look at your map for you if you would like a second
set of eyes.


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi