Patrick,
You are pretty much correct in your statements in regards to power and
efficiency, but there is another part to this equation and it is called
NOx. As power is
increased through efficiency, (more fuel, air and better combustion),
combustion temps. rise and NOx increases and it is not linear. The
automakers use EGR
equipment to dilute the fuel/air charge to slow the burn and reduce
cylinder temps. and pressure. Federal emissions requirements now include
a dyno run at
idle and cruise (generally around 2,000 to 3,000 RPM) to test for NOX,
we already have it here in Calif. The approach for street driven
vehicles when it comes to power should be to know the emissions levels
allowed (HC's, CO, CO2, & NOx), and the weaknesses surrounding the test
(eg. no test for WOT). and make changes to take you up to but not over
the limits (we can't hide from the EPA Gods). Fuel injection is far
better than carburation when it comes to emissions, but they don't look
at that relationship, (only year and model requirements) and I would
hate to go back to the days of carburators on new street vehicles.
> -----Original Message-----
> From: Patrick and Kelly Engram [SMTP:shetland@erols.com]
> Sent: Monday, August 10, 1998 8:47 PM
> To: dakota-truck@buffnet.net
> Subject: DML: Hi po computers and emissions
>
> Some one was writing in about how dirty their truck might be and fail
> emissions by using an ungraded computer.
> To maximize power, the computer is designed to precisely meter the
> correct amount of fuel and burn it the most effectively to give
> maximimum power output, and this is done in closed-loop via the oxygen
> sensor. In other words, maximizing power, if done correctly, should
> minimize emissions.
> To back up my point, here are the readings from my last emissions
> test. Keep in mind that I run headers, hi-flow cat and exhaust, hi
> flow
> fuel injectors, upgraded cam (mopar stage 1), computer, jacobs
> ignition,
> and so on.
> HC= 55 ppm, state standard 220 ppm
> CO= .12 % state standard 1.20%
> CO2= 14.4% state standard 6.0%
> You can get any cleaner than that. I'll tell you what, I was even
> surprised how clean it was!
> A properly designed fuel injection system with the proper cam setup
> will probably beat a carbureted setup everytime because of the
> feedback
> capabilities of the fuel injection computer system, and how it can
> optimize fuel delivery and spark timing.
> They tried to do this with carburetors-remember the old feedback
> electronic carburetors?
>
> Patrick
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