10V T pics-detonation

Jörgen Karlsson jorgen.m.karlsson at home.se
Thu Sep 27 11:15:40 EDT 2001

> > While I am guessing:
> > I don't know the AFR where the 10vt are most likely to detonate, this
> > are not the same for all engines. But I think that everyone will agree
> > all engines detonate easier at 13:1AFR then at 16:1AFR. With my latest
> > cuts in mind I guess that 13:1 to 13.5:1AFR is very dangerous, it is
> > easy to end up in that range since the car will feel very strong at
> > AFRs.
> I don't agree! You have it backward, a 16:1 AFR is MUCH leaner than 13:1,
> and for the most part, a richer mixture gives a cooler combustion chamber
> and less potential for detonation. AFR of 16:1 is WAAAYYY lean, Lambda 1
> 14.7:1, and most turbo engines run 12-13:1 in full boost.
> Mike

You missed the point, I know that 16:1 AFR is on the lean side of lambda=1.
But it is more likely to have a detonation at lambda=0.88 (13:1) then at
lambda=1.088 (16:1AFR).

Just like Javad's example told us, at a very (17:1-18:1 AFR?) lean mixture
the engine can handle a lot of boost without detonating. There will of corse
not be any power to talk about but that was not the point.

You may find http://naca.larc.nasa.gov/ interesting.


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