The landscape for building and evaluating circle-track engines is on the verge of new opportunities to incorporate some updated thinking. What does that mean? In reality, several factors come into play. Let's examine a few of them that may apply to us of the engine contingency.
Arguably so, chassis-minded circle track racers often advance the belief that power is power and it's an ability to put it on the track that counts. And, from many perspectives, that's a valid viewpoint. But in the background of we who are continually looking for ways to improve engine performance, there's a growing concern about and interest in making "efficient" power, for various reasons. It could be class rules that limit piston displacement or the allowable selection of power-enhancing components. Possibly a "spec" fuel is required. And the list continues. Further, within such restrictions, engine builders not only seek ways to circumvent or "interpret" the rules to some advantage but continually probe areas that yield an on-track power benefit.
From a practical standpoint, this quest for an edge leads to finding ways of evaluating changes that may either point toward or quantify the gain. Air flow benches, engine dynamometers, PC-based software packages, and other means of evaluation are frequently the yardsticks-the results from which are typically enhanced by operator skills and experience. And, quite frankly, the level of intellect now woven into the fabric of circle track engine development includes participants of the highest academic levels, populating the established network of builders who've accumulated decades of well-earned knowledge in the hard-knocks trenches of racing.
The Portable Emissions Measuring System or PEMS from Sensors Inc. has been used primarily
So what's the point of all this rhetoric? Changes in the way an engine's combustion efficiency is measured are emerging at the "grassroots" level, if you'll allow me the use of that term. On a week-to-week and season-to-season basis, these are the people who provide the experience while advancing the sport and business of circle track racing. Well, there's a new tool they may soon be using and, believe it or not, it's emerging from the environmental community where an engine's exhaust emissions are of concern and measured.
In the course of sharing this monthly column with you, we've advanced several ways to utilize a variety of engine conditions and measurables. Understanding engine cycle analysis (real-time cylinder pressure vs. crank angle data), reducing brake-specific fuel consumption (b.s.f.c.) into its elements for evaluating combustion efficiency, ways to quantify airflow pressure distribution maps in an induction system, and some of the basics of intake and exhaust parts selection and matching have been discussed. What he haven't chosen to do is introduce ways that evaluate combustion byproducts, as they pertain to how efficiently an engine is converting fuel into heat (power) . . . until now. It turns out this may be a new frontier by which racing engines are placed alongside their production, on-highway counterparts to determine not only emissions output but (coincidentally) become built to even higher levels of power and efficiency.
Note the sensor in the left header's collector. Although shown here on a fuel-injected LS3
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.