rev limiter

[Joel Mello]

See below...

[-------------- snip --------------]
>  I see what you're saying now. Each miss is equal to one pump of unburned
>air/fuel in the manifold/exhaust system/turbo. More misses=bigger bang.
(light->bulb on above head)
>  
>  I'm kinda handy with a soldering iron, but new to making radio-shack
gizmos. >I might try to make something from a 555 timer that is adjustable
for percent >of miss. Any hints for a newby are welcome.
[-----------------------------------]

Here's something that just popped into my head as I was reading this mail. 
Basically, you want a rev limiter, but you don't want the 'banging' to occur
in the turbo.  Here's something that you could implement:

If you're controlling your own injection (meaning that you've built your
ECM, and you can reprogram it), you might be able to solve the banging
problem permenantly.  If your engine/ECM utilizes SEFI (each injector gets
an individual pulse), you could have the ECM miss __BOTH__ a cylinder's
injection of gas, AND spark.  This would cause the cylinder to simply
compress air from the lower/upper manifolds, but wouldn't throw a spark to
it.

Doing this would result in one full cylinder of air to be dumped out into
the exhaust manifold, but it wouldn't have any gasoline it in, which means
it wouldn't ignite further on down the line (causing the banging).  This
method of rev-limiting would cause the O2 sensor to pick up more O2 than
normal, which would make it think it's running lean, but -- this shouldn't
really matter, as you should be at WOT, which means that the ECM ignores O2
readings.

Just an idea.

Joel


Joel A. Mello
Email - Mr-mello at excite.com
Phone - (775) 265-4380
Web - Http://homepages.go.com/~joelmello/





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