Note the sensor in the left...
Note the sensor in the left header's collector. Although shown here on a fuel-injected LS3 engine, the PEMS device can be effectively used on a circle track engine to locate horsepower gains through the analysis of the engine's emissions. Jim Mcfarland
OK, that's a mouthful, but it has relevance to circle track racing. Many of us have already experienced the impact of noise abatement at racetracks. Exhaust system parts manufacturers (notably for mufflers) have addressed this issue, at least to some extent. And, thankfully, the focus upon track, driver, and spectator safety has increased considerably in recent years. But what about racetrack air quality? Are there ways to have a favorable impact on this issue without stifling on-track competition and spectator appeal? Will current concerns about the use of gasoline, including those of a political nature, become problematic for circle track racing? At the moment, it's not abundantly clear how these factors are going to play out, but the magazine you're holding is taking some initiatives on your behalf. And while it's a bit premature to share our plans at this point, following is an example of what you can expect to see more in the coming issues of CT.
A few months ago in this column, we shared some comments from a well-known and recently-retired GM executive, Herb Fishel, up to his wheelwells in a massive green racing program's development. The initiative in which Herb is involved has triggered numerous satellite activities, one of which addresses concerns about racetrack environmental factors. In the context of this activity, I became aware of a relatively new technology I'd like to share. It has a bearing on the subject at hand. You will be hearing more about it, sooner than later.
Essentially, the product enables an engine's exhaust emissions to be measured, virtually in real time. While this capability has been primarily directed to environmental concerns, here's how it can work in a racing engine development atmosphere. Of the emissions measured, one is oxides of nitrogen (NOx) in the exhaust stream. NOx is combustion heat related and can be used when comparing brake horsepower (where power measurements are made at specific engine speeds and loads) with simultaneous oxides of nitrogen emissions data. For example, a "fast burn" combustion process can net a power gain and be accompanied by a reduction in NOx, within the exhaust gas. How, you ask? Essentially, because more useable combustion heat was liberated to providing productive work and residual temperature was thereby reduced prior to beginning the exhaust event. Thus, modifications to an engine outside its combustion space can be quantified beyond the scope of a power change. Elements as to "why" the event occurred are determinable, then leading to how further changes can improve net engine performance. This has a cascading effect on analyzing the progression of engine modifications.
So you can quantify this efficiency improvement by noting the degree of NOx reduction and, therefore, use emissions measurement as a "design" or analysis tool during dyna-mometer evaluations. Interesting? Furthermore, it's not too far-fetched to imagine a time when racing engines (regardless of the fuel type) will be built/developed by including emissions measurements as a prerequisite to meeting some level of environmental requirements-voluntary or otherwise. And don't forget about the use of low-restriction catalytic converters.
As an analysis and development tool, we recently observed such testing during which a range of emissions were measured (including unburned hydrocarbons [HC], carbon monoxide [CO], oxides of nitrogen [NOx] and carbon dioxide [CO2]) during a specific engine dynamometer test session. The equipment used (understandably) is called a "portable emissions measuring system" (PEMS) as built by Sensors, Inc. (Saline, MI). It's a technologically remarkable device. You can check it out at www.sensors-inc.com. Click on the SEMTECH products and take a look.
Of course, the key word here is "portable." Does that mean it can be used on-road? Yes. Off-highway? Yes, again. On a racetrack and in a race car? Thought you'd never ask. Certainly. In fact, at the risk of getting ahead of what's to come, this type of equipment stands to play a key role in material you can look forward to seeing in future issues of this magazine. The plans are forming, some of which are already made, and you'll be privy to getting a first-hand look at portions of what appears ahead on the horizon of motorsports.
Integral to the material you'll be reading are the parts that relate to circle track engines, thus the reason for discussing it in this column now. Power measurement as a function of exhaust emissions will be included, connecting the combustion process with techniques about which you're already familiar for analyzing engine dynamometer data. It's part of the next step in developing not only future engines for circle track applications but parts that enhance their performance. It's also a direct link for enabling our ongoing sport to become and remain more environmentally responsible, an issue that appears as unavoidable as the opportunities such changes will bring.