Scotty

[MARK 99STS]

Hi Scotty,

Any ideas on how the HP dosen't change with a change in A/R ratio? Unfortunately we don't have BBob to help us out.

Also since the base dyno done by Corsa showed 206 HP I have to assume a loss of about 94 Hp from the flywheel to the wheels. Adding that back to my dyno results I should be pushing about 344 HP. I was very close on my guess of 350 HP.

[Scotty]

Hi Scotty,

Any ideas on how the HP dosen't change with a change in A/R ratio? Unfortunately we don't have BBob to help us out.

I think that some of the other guys will chime in on this one, but my guess is that it has to do with Stoichiometric Combustion which is the the ideal combustion process during which a fuel is burned completely. A complete combustion is a process which burns all the carbon © to (CO2), all hydrogen (H) to (H2O) and all sulfur (S) to (SO2). If there are unburned components in the exhaust gas such as C, H2, CO the combustion process is uncompleted.

Excess Air is defined as the amount of air in excess of the stoichiometric amount. It is common to use more air than the stoichiometric amount in the combustion chamber. It increases the chances of complete combustion. Excess air can also be used to control the temperature of combustion chamber.

My guess is that you were just exhausting unburned fuel when you were running rich?

See this related link

http://www.cadillacforums.com/forums/showt...hlight=air-fuel

[Scotty]

Rich fuel mixtures resist detonation while lean ones do not.

Air leaks in vacuum lines, intake manifold gaskets, carburetor gaskets or the induction plumbing downstream of a fuel injection throttle can all admit extra air into the engine and lean out the fuel mixture. Lean mixtures can also be caused by dirty fuel injectors, carburetor jets clogged with fuel deposits or dirt, a restricted fuel filter or a weak fuel pump.

If the fuel mixture becomes too lean, "lean misfire" may occur as the load on the engine increases. This can cause a hesitation, stumble and/or rough idle problem as well.

My guess is that the stock computer is programed to richen up the mixture on power demand.

I put a question out to a friend of mine to see what he thinks, maybe it has to do with timing also.

[Scotty]

Here was some interesting information:

http://www.knfilters.com/airfuelmonitors.htm

[Ranger]

Just a shot in the dark here, but could the O2 sensors be sending the info back to the PCM and it is making the corrections and overriding your inputs.

[MARK 99STS]

Just a shot in the dark here, but could the O2 sensors be sending the info back to the PCM and it is making the corrections and overriding your inputs.

If that were true, then the wide band from the dyno test would have shown no change in AFR. The readings came from their wide band up the tail pipe, not from my computer proving that there was a change in AFR.