Glossary of Terms - VEC3 and Roe Supercharger

[DAMN YANKEE]

I have prepared a glossary of many of the important terms used when discussing operations surrounding the VEC3 and Roe Supercharger. These include terms like long-term Fuel Trim Additives, Lamda, Injection Pulse Duration, Duty Cycle and a whole host of little gems like PCM, Pull, PWM, IAT, IAC, etc. etc.

For most, this is, understandably, useless stuff, for others involved with, considering or interested in the VEC system it is a solid glossary. This is my effort to explain these terms for my own use as I work through a full blown VEC3 build-out with the intent to fine tune a supercharged engine.

I would normally just put up the Word file on a forum thread, but that function is, understandably, turned off here at VCA. If anybody has a good idea of how to make a Word file available to all, please let me know.

Neither sanctioned or official, I offer it up for general consumption as a work in progress. Questions, additions, corrections, comments are all welcome and appreciated. Hopefully, we will get to the point where the Illustrated Guides will include VEC or INNOVATE (or, as in my use both) build outs among other more advanced projects.

 

[V10SpeedLuvr]

I would just copy and paste the glossary into this thread

 

[DAMN YANKEE]

Thought of that...its too long.

Example, a single entry

Lamda

When air and gasoline are mixed together and ignited, the chemical reaction requires a certain amount of air to completely burn all of the fuel. The exact amount is 14.7 lbs of air for every pound of fuel. This is called the "stoichiometric" air/fuel ratio. It's also referred to the Greek letter "lambda." When lambda equals one, you have a 14.7:1 stoichiometric air/fuel ratio and ideal combustion. When the air/fuel ratio is greater than 14.7:1, lambda also will be greater than one and the engine will have a lean mixture. Having stated that, it is important to note that, under load, a normally aspirated motor may perform best at 12.9:1, while a forced induction motor may perform best anywhere from 11.5:1 to 12.5:1 depending on air temperature and other variables.

Lean mixtures improve fuel economy but also cause a sharp rise in oxides of nitrogen (NOX). If the mixture goes too lean, it may not ignite at all causing "lean misfire" and a huge increase in unburned hydrocarbon (HC) emissions. This can cause rough idle, hard starting and stalling, and may even damage the catalytic converter. Lean mixtures also increase the risk of spark knock (detonation) when the engine is under load.

When the air/fuel ratio is less than 14.7:1, lambda also is less than one and the engine has a rich fuel mixture. A rich fuel mixture is necessary when a cold engine is first started, and additional fuel is needed when the engine is under load. But rich mixtures cause a sharp increase in carbon monoxide (CO) emissions, generating more heat at the catalytic converter with resulting damage.

When the relative proportions of air and fuel are "just right," the mixture burns clearly and produces the fewest emissions. The trick is balancing the mixture as driving conditions, temperatures and loads are constantly changing.

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Its just too long for the threads.....

 

[NoRice]

Save it as a pdf host it somewhere and post the link. Or at the very least email to me.

james-at-vasnv-dot-com

 

[SYNFULL]

Don't mean to hijack your thread, but can anyone tell me the difference between vec 2 and 3. Roe doesn't even have the vec 3 listed on their site as far as i can see.


Thanks
Gary

 

[Knight Viper]

Not sure of the best way to post them but I do know a lot of us blown and NA guys would love to read it. Knowledge is POWER.