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Data Acquisition Systems and Engine Controllers
Engine builders - especially those building performance engines - must become part computer geek as well.
By Brendan Baker
Motorsports in general and Formula One in particular is the leading edge (or bleeding edge, depending on how you look at it) of development of these electronic systems. With carburetors looking more and more like dinosaurs compared to modern electronically controlled engine management systems, engine builders - especially those building performance engines - must become part computer geek as well.
Flip on the television to a Formula One, Champ Car, IRL or, to a lesser extent, NASCAR race and you will notice almost as much coverage about the technology in the sport as you do about the race. What used to seem like space-age gadgetry has, in fact, become reality. Computers, almost as much as the mechanical components themselves, run the racecar, and through the many inputs, outputs, sensors and telemetry, race engineers and crew chiefs play as an important role in the outcome of a race as the driver.
An outspoken former Formula One driver once said that thanks to the age of electronic everything a monkey could just as easily drive a Formula One car. Obviously, most drivers strongly disagreed, but team managers were suddenly scampering to put the first monkey under contract or at least use one as leverage to help negotiate their driver's upcoming contract.
In this age of electronics, building a modern race engine or even a high performance street engine requires some computer knowledge, without a doubt. You don't have to be Bill Gates or Steve Jobs of Apple to run the necessary programs needed to tune these engines, but having their resources wouldn't hurt.
Along with the engine management system, engineers analyze logged data from the ECU and other sensors on the car via another piece of high-tech wizardry called Data Acquisition Systems (DAQ) so they can view and manipulate "real events" and generate useable information from such things as crank position, manifold boost pressure, steering angle, wheel speed, brake pressure, and so on.
There are a plethora of choices in the performance ECU and DAQ markets respectively. We talked to noted data logging and engine control system experts to find out some of the options that are available for engine builders. We also wanted to know how interconnected these systems are and how advanced the technology has become.
It's important to know what features these systems have and how they operate, so you can make the best choice for your racing customers. Although, most engine builders will not have much to do with the DAQ systems it may be beneficial to know how the data is collected and viewed as a complete electronic system.
On the ECU side of the aisle, there are several distinct types of systems, and some that fall somewhere in between. If you are building an engine for a customer's club-level car you will not need the same level of features that a top professional team would need (although it would be nice to have if your customer wanted to pony up the money for one).
"The way I see it is there are really only three tiers in the ECU market," says Neel Vasavada, Apex Speed Technology, a dealer, developer and tuner for several lines of ECUs including Pectel, Motec, AEM and EFI Technology. AST also helps develop many of these systems for the manufacturers.
According to Vasavada, the low-end ECU market consists of more basic systems with few extra features. "The Holley 850 Commander is a low-end system in the sub-$1,000 range of ECUs, and these types of systems are mainly for hobbyists," explains Vasavada. "It's mainly for people who don't need a lot of sophistication and who don't necessarily need a lot of the high-end reliability features. Mid-range ECU units include AEM and Autronic (for which they are dealers also) and have more of the high-end features, but they don't have all the bells and whistles."
Vasavada explains the differences between mid-range and high-end ECUs to his customers this way: "A Geo Metro and a Mercedes Benz S600 both have air-conditioning, but the Mercedes has automatic climate control which cools the seats and your sandwich in the glove box, and it switches to an activated charcoal filter when you pass a diesel truck. Both accomplish the same goal of cooling the passengers, but the Mercedes has a much more sophisticated system."
Vasavada says he doesn't push any particular brand of ECU over another but he knows from experience what works best through working with his many racing customers. One of Apex Speed Technology's customers is Intersport Racing in the American LeMans Series LMP2 class to which AST is the supplier of all the electronic hardware (ECU and DAQ systems) and software.
"I think we are one of the only dealers in the country that represent such a wide line of engine management systems," says Vasavada. "And on top of that, we tune all makes and models of ECUs, and we have quite a bit experience tuning Autronic, Bosch and others as well. We work with manufacturers like Motec, Pectel and EFI Technologies to develop new features and new products."
Industry experts say that one of the biggest differences between ECUs is that the high-end offers a level of sophistication and control that is beyond what the mid-range ECUs can do. "The proof is in the pudding," Vasavada states. "You just don't see mid-range units in professional motorsports."
Experts say one of the biggest difficulties in choosing the right ECU for your application is that you can look at many of them and see similar features. You may think they are the same thing, but they are not. There are some distinct differences.
"With ECU's, like the Pectel system for instance, you can add an accelerometer and a beacon and draw tack maps," Vasavada notes. "So you can do maps with it and set up many different kinds of plots."
He also notes that some of the high-end ECUs also take on certain features of a DAQ system, allowing you to control and monitor parameters that were once the domain of a standalone DAQ system such as traction control strategies and ability to drive a dashboard, as well as allowing unused pins to be used for other sensors. So the high-end ECUs are much more flexible in what you can do with them.
Pectel SQ6 ECU
One of the powerful newcomers to the mid- to high-end market is Pectel Engine Control's SQ6/SQ6M system. According to Julian Wray of Pi Research, parent company of Pectel, the SQ6 has a full-line of features including on-board data logging in this high-end but mid-priced system.
"We've done a lot of development work with single-make spec series classes so we could find out what these engine builders needed from an ECU," Wray explains. "We have worked with Formula Ford series right through to Formula Atlantics and now we're working with the 2007 Champ Car program. During this course we've learned a lot of information about what a spec series requires and wants. We have things such as engine logbooks built-in, so you can log all the starts, and engine builders can use various levels of editing in the code to customize the system for their use. Several manufacturers, like Nissan for example, can make a base map and then give it off to engine builders in that series to tune further. In a spec series this works very well. We call it a developer ID or sub-developer."
Wray says that manufacturers aren't particularly eager to hand out base maps but in the case of a spec series with one engine supplier it's beneficial for the manufacturers to do so for a certain level of protection. Otherwise engine builders would be starting from scratch and have to build the entire map table themselves. Additionally, Wray points out that in one-off situations where the manufacturer does not support the series or provide a base map, Pectel will step in and supply one for engine builders to have a starting point. That way you don't have to do everything completely from scratch.
One of the more unique features of the SQ6 ECU is its crank pattern recognition system. According to Wray, Pectel has developed a more sophisticated algorithm to recognize many different types of patterns.
"It actually has a processor that is dedicated to synchronization," says Wray. "In many cases it's sometimes difficult for an ECU to recognize complex patterns, whereas this system has been specifically designed to read any tooth pattern. It has to be configured for the specific application, but it's very flexible. And rather than forcing engine builders to use a specific trigger wheel or have to modify an OEM system, this system has the ability to be configured to recognize the more complex systems."
The crank pattern can be configured within the mapping software, DescproW, which is the companion software for the SQ6 ECU. The Descpro software allows you to edit the map on the fly so you can see the changes instantly, in real-time, with the engine running, according to Wray. One of the key things in the calibration tool software is the ability to log your way through the process so that you can find your way back should you happen to go down a dead-end road.
According to our experts the SQ6 is very comparable to the Motec M800. The M800 has many of the same features and capabilities and some believe it is the best package available right now because the software has more built in support. But experts also agree that the SQ6 is a very formidable challenger and for about a two-thirds the cost.
"We are also Motec dealers, and I think they make some of the best ECUs in the world right now," says Apex Speed Technologies' Vasavada. "When you compare apples to apples and you get the Motec M800 with all the options that are standard on the Pectel system, the Pectel system is at least a third less expensive. And the hardware, I think, is more sophisticated. But the Motec system still has the best calibration software, which is the I2 interpreter and V3 engine software. Motec has added more base support features; for instance, Pectel still hasn't added 350Z drive-by-wire motors to their software even though the hardware is there to run it. As Pectel continues to develop their software, they're going to catch up very quickly, but Motec has had more time to develop their package at this point."
Vasavada also says that he believes for engine builders doing high-end V8 engines, engines that don't need to have features like variable valve timing and drive by wire throttle control - the SQ6 system is the best value available.
Data Acquisition Systems
Often electronic systems have been referred to as the "brains" of the racecar but if that's the case, you might look at the data acquisition system as the "logic" part of the brain. For the most part, engine builders won't be working on the DAQ systems, but there are some interesting areas that overlap into engine control areas. Today data acquisition systems come in many forms and for many different sized budgets. Depending on your hardware needs, a DAQ system can run over 100 different channels of sensors that are measuring real time events from air-speed and pressure, to wheel speed and suspension load sensors. Simple systems may run 2-4 channels in a go-kart and up to 60-plus in a Champ Car or IRL car, and Formula One cars may run over 100 different channels. A simple but useable DAQ system may cost as little as $2,000 and be tied in with your ECU to give you full functionality to run systems, monitor and log data. High-end DAQs are quite a bit more costly, but have many more features and channel inputs/outputs. Much of the development has been for lighter and more powerful systems that have been adapted from Formula One, of course.
"Through our Formula One relationships, we've developed a lightweight, powerful system that is very resilient," says Pi Research's Wray. "The electronics for the junction box can be mounted on the back of the gearbox, which is a huge advantage because it saves all that extra weight in the wiring harnesses and other junctions that may have been needed. It's able to survive in high temperatures (up to 239° F), and it's a network across the car instead of running all sorts of sensor links all over the place. The sensors are now connected more locally around a 'node module.'
"If you look at one corner of a Champ Car, for example, there are a number of sensors being driven such as tire pressure, tire temperature, brake disc temperature, brake upright travel, brake caliper travel, upright temperature, suspension load, shock position and travel, etc - just on one corner of the car!" Wray points out.
Sensors are driven through either the ECU or the DAQ system and can be monitored and logged through a telemetry system, which is essentially a radio network that connects the car's sensor output and feeds the signal to pit lane in real-time, so engineer can monitor any problems and make strategic race decisions during the race and improve the performance of the car.
There are a couple of different ways teams log data from the computer systems on the car. It is not always possible to stream all of the channels over the radio and into pit lane, so many teams use a logger box to record all the data for downloading at a later point, such as when the car comes into the pits for practice. The data that is streamed over the radio is logged at the box but also can be logged at the computer in pit lane.
"In the event that the car stops on the track," says Wray, "you can look at your logged data and you don't have to wait to plug in and download the data. This is a pretty powerful feature in endurance events where it's a long race and a team may have several cars and you want to find out why the car stopped. The telemetry may reveal an injector problem or some other sensor issue that would red flag a problem."
Common to both engine controllers and data systems is an analysis software package. One of the prime abilities of this software is to monitor many layers of information and analyze it very quickly. It's basically a workbook with individual sheets that can be pre-configured for looking at the same things all the time, so you're not continually manipulating graphs and scaling things. You can pre-build all of the parameters you want to have instant access to and then very quickly monitor the data characteristics in the engine and chassis coming from the ECU and DAQ.
Pi Research's Pi Toolbox software is widely recognized as being one of the most convenient tools for race engineering, says Wray: "It can be massively customized for almost innumerable user preferences. There is a whole suite of channels and graphs and channel displays, maps, etc. The result is you can get at your data very quickly and identify certain characteristics, rather than endlessly searching through traces and looking up values and bitmap indicators and a whole range of controls that aren't formatted."
Current generation ECUs and DAQ systems are evolving into more lightweight and powerful systems, and the price to enter into this technology is also dropping. This may mark the beginning of the computerized racecar which is affordable to more and more of your race engine customers, so now's the time to brush up on those computer skills.