OT: HHO (Browns Gas) Conversion For Your Car
alex.esplin at gmail.com
Wed Jun 11 23:55:00 MDT 2008
On Wed, Jun 11, 2008 at 11:39 PM, Levi Pearson <levi at cold.org> wrote:
> piston and/or cylinder apart or bending the rods. High-compression
> gas engines are more efficient, but they also require high-octane fuel
> to avoid pre-detonation.
> Turbocharging effectively increases the compression ratio, making
> pre-detonation even more likely. Thus, timing has to be pulled and
> more fuel added as boost increases beyond atmospheric pressure, which
> dramatically reduces efficiency and power below what optimum spark
> timing and fuel mixture would bring. This is why turbocharged gas
> engines can be tuned to much higher performance on race gas than pump
This is why all decent engine-management systems advance the timing of
your ignition cycle when the turbo is making boost. Obviously there's
a limit to how far you can advance your timing, but in order to be
"safer than sorry", many production, stock engines actually fire
slightly after top-dead-center. Advancing the timing as close as you
can to top-dead-center slightly mitigates the problem.
Timing advancement is _not_ a substitute for effective octane level.
It merely helps a little. And you are correct, in that a turbo only
increases efficiency when it is producing boost and the amount of fuel
stays constant. Which is why my Passat got better mileage at 90+ mph
(turbo was making boost but the valve timing was still in "cruising"
mode) than at lower speeds. The combination of slight boost + slight
timing advancement with (nearly)constant fuel consumption made it more
efficient. That was one of the things I hated about that car.
Because the powerband vs. boost-production curves weren't very well
matched it got _horrible_ mileage in-town (usually below 20).
Well, brethren, I believe we have beat this horse well beyond death
and are bordering on the glue phase.
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