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Engine data can be very
helpful for increasing both performance and reliability.
Drag racers and tractor pullers, for example, find that
knowing what the Exhaust Gas Temperatures (EGT) and supercharger
boost were during the whole run. This allows them to tune the
engine for performance and to prevent expensive
meltdowns. Many racers also monitor fuel pressure and
nitrous pressure for the same reason. Several customers
have reported that the system saved them an engine by letting
them detect a problem before the engine was destroyed.
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Engine RPM is the most
basic thing to record. Knowing RPM at every instant is
a big help, especially combined with g readings and throttle
position. In any class where you can change your gear
ratios, this is very important to be competitive. A tach
with a telltale might tell you that max RPM was 8200,
but you don’t know if that was once, or every lap.
Corsa Data Acquisition systems can show the exact engine RPM every moment on the track. You can even get a histogram that tells you
how much time the engine spends at each different RPM
range. You can combine this with throttle position
or accelerometer data so you aren’t fooled by the
times when the driver was off the gas.
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Troubleshooting is much
easier with a data recorder. If you have a miss or a stumble
or if you’re just a little slower than you’d
like, you can look at the data and see what’s causing
it. Was the boost pressure up where it should be? Were
there any dips or problems with fuel pressure? Did you
have one cylinder going cold (or worse yet too hot)? Was
the engine turning the RPM it should? Was the clutch or
torque converter working properly? Were you getting more
wheel spin than you want? We have all seen teams struggle
chasing a “mysterious” problem. At Corsa we
often hear from customers “We found our problem
the first time out with the Corsa system. I wish we had
bought this sooner!”
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Wideband air-fuel-ratio (AFR)
sensors are extremely useful for tuning carburetors or
fuel injection systems. The Corsa AFR sensor gives you
a graph showing the exact air-fuel-ratio (for example,
13:1) under all conditions. You can see how the fuel mixture
changes with RPM, and how it changes with load or throttle
position or other variables. This is exactly the information
you need to tune and troubleshoot your fuel system. It’s
much more convenient and accurate than reading sparkplugs
and it can show you the conditions all through the race
– not just what the sparkplug saw the instant before
the engine was shut down. Note that the Corsa AFR sensor
is a true wideband unit that will give accurate readings
from about 10.5 :1 to17:1. Inexpensive "O2"
sensors only tell you if your fuel ratio is lean or rich.
They can't tell you if you're only a little bit lean or
about to destroy your engine. Our sensor can help you
quickly determine how much tuning you need to do. The
Corsa AFR sensor will work with leaded or unleaded gasoline,
alcohol, and other fuels. (Sensor life is reduced when
using leaded fuel.)
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Driver development in
road racing and oval track racing can result in very large
improvements in lap times. A data recorder allows the
driver to analyze what he’s doing, and how to improve.
If you have two drivers, they can compare their laps and
see where each one gains or loses time, and why. A driver
can compare his best lap to other laps and see where the
difference is. Drivers can try different techniques or
styles and see what difference they make. Many customers
report a substantial improvement in lap times from analyzing
braking performance alone. In addition to stripcharts
and other data, the Corsa system can display the “traction
circle” which is a way to see how fully the driver
is using the car’s potential. The DeBrief 3 software
automatically makes a map of the track and plots the data
within the map so it’s easy to understand what you’re
seeing.
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Vehicle and suspension tuning.
A data acquisition system can help you tune almost every
part of the car. You can spot understeer and oversteer
in the data. You can see how the car responds to the driver’s
input. With suspension position sensors you can measure
body roll, squat and dive, and wheel motions for suspension
and shock absorber tuning.
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Before and after testing.
When you make a change on the car, you’d like to
know what that change did. Lap times are part of the story,
but some changes help the car in one place and hurt in
another. With the Corsa system, you can look at data from
before and after the change was made, and see exactly
how much it helps or hurts performance at every instant
on the track.
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Ease of use: Our wireless
One Button Download means that it's extremely easy to
get, use, and quickly understand your data. The Corsa system is designed
to be easy for ordinary racers to use.
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Expandability: The standard
Corsa system comes with 11 channels, and there are expansion
boxes to add as many channels as needed. You can easily
add more sensors later without having to throw away or change your
existing equipment.
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Price: The Corsa system
is very reasonably priced compared to other systems. We
want to make the competitive advantages of data acquisition
available to the average racer.
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Support: Corsa has free
toll-free phone support. Our staff are very willing to
help you solve your problems.
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Experience: Corsa has
been in the racing data acquisition business since 1991. We've learned over the years how to help people in ways they may not have even realized.
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Improve your Performance!
Using the Corsa data acquisition system will help you
learn more every time you go on the track. You'll be able
to get a good setup in a very short amount of time, be able to spot expensive problems
before they become expensive, and best of all, lower your track times quickly. Those are
real competitive advantages for every team.
How can I understand
all that data? ( Back To Top)
Some of it is easier than you think. Many of our customers
start out with one question; a variable they already know
they need to measure. For instance they want to know how much
torque converter slip they have, or they need to know turbocharger
boost pressure. Generally you can answer a question like that
the first time you use a Corsa Data Logger. You can look at the
graph of boost pressure versus time in the race for instance,
and it’s easy to understand.
The next step is to look at more channels and see how they
relate to each other. For instance you can put engine RPM
and driveshaft or input shaft RPM in the same window and
see the differences. This is your torque converter or clutch
slip. You can get fancy and make calculated channels to
read slip directly in each gear, but just looking at the
engine RPM in detail all during the pass and comparing it
to driveshaft RPM can tell you a lot. Similarly you can
look exhaust gas temperatures (EGT's) to see if the engine
is running too rich or lean. Then compare the EGT graphs
for all the cylinders, and see what you can find. Every
engine is different, but for your engine you’ll probably
have a pretty good idea what it means if cylinder 1 is running
hotter than the rest and what you might do to change it.
Once the basic questions are answered and a few different
races have been recorded, the smart racer will start asking
questions. “What caused this funny dip in the accelerometer
trace?” Or, “What can I see in the data that
relates to a problem the driver reported at this point on
the track?” That’s the fun part – using
the data to improve your performance.
What about accuracy and resolution?
(Back To Top)
The accuracy of the Corsa system is more than adequate for
almost any application. Wireless Corsa Data Loggers are 16 bits digital
and 12 bits analog. Accuracy is one part
in 4096, or about 0.025% of full scale for analog measurements.
If you are measuring pressure from 0 to 200 PSI, the data
is accurate to 0.05 PSI. As accuracy depends on good installation of quality sensors, Corsa only supplies sensors that have been tested and proven superior. In other words, Corsa Data Loggers are is extremely accurate.
What kind of PC is needed to use
the Corsa system? (Back To Top)
You need a computer that runs Windows 98 or later (Windows
ME is not supported). It needs to have a USB port for the Corsa radio, and at least 25mb disk space available. You don’t need
to take your latest and most expensive computer to the track,
an older laptop will do fine. You could even install an old desktop computer
in your trailer!
What if I need help installing my system? (Back To Top)
In addition to our installation and operations manual, Corsa
offers free technical support over the phone and via e-mail.
We can help you get up and running with the system, answer
questions about sensor hookup and anything else. You can
email us your data files and we can discuss them with you
on the phone.
We also offer paid installation and support services. A
Corsa technician can meet you at your shop, at the track,
or you can bring your vehicle to our shop in Michigan. We
can help you install the system, we can help you learn to
use it, and we can help you analyze your data at the track.
In some cases, we have been able to work informally with
teams on special projects. Whenever possible, we do like
to meet our customers at the racetrack. We can’t guarantee
free at-track support, but call us about your project and
your schedule and we’ll see what we can do.
Can I hook it up to my fuel injection
system? (Back To Top)
The wireless EZ II Data Logger can usually be hooked up to the sensors
your fuel injection system already has. Vehicle speed, engine
RPM, and throttle position are common examples. The Corsa
system has an optional CAN bus interface that can read data
from your ECU if it has CAN output.
What sampling rates should I use?
(Back To Top)
This depends on what you’re measuring, and what type
of racing you do. You need to sample fast enough so you
don’t miss an important change, but if you sample
too fast you spend a lot more money and end up with huge
data files that don’t really tell you any more. Some drag racers sample EGT’s 100 times
a second, but the truth is that the thermocouple physically
can’t change temperature that fast. On the other hand,
you need 100 samples per second or more to measure shock
absorber velocity. Here are some suggestions:
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Drag racing: Start with
20 samples a second for each channel. That is fine for
most sampling except for suspension motion during the
launch.
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Tractor pulling: 20
samples a second is good.
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Road and oval track racing:
10 samples per second is common for driver inputs and
vehicle acceleration. The driver and the car can’t
do much in less than 1/10 second. Faster sampling is
only good if you have memory to spare; it's not essential. Because road races are longer, you need either slow sampling
rates or a lot of memory.
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Suspension and shock absorbers:
For body motion (roll, squat, dive) 10 or 20 samples per
second is usually good.
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Shock velocity measurement:
100 - 500 samples per second. This high rate is needed
partly because shock position data is differentiated in
the software to get shock velocity.
Are there non-racing applications?
(Back To Top)
Corsa data acquisition systems are currently being used in a variety of applications. We have customers measuring and testing everything from
aerobatic aircraft to heavy equipment. Corsa systems can
be used on dynos or test bench setups as well as on on in vehicles.
Corsa systems can work well for field test or equipment
monitoring, as well as for development testing. If you have
an application outside racing, please call us to discuss
how we can help. Here are a few points to consider:
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Price: Wireless Corsa data logger systems
are extremely reasonable compared to most other industrial
data acquisition systems.
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Ease of Use: Corsa systems
can automatically start and stop recording as needed and
work with no operator intervention.
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Long recording times:
The EZ-CF datalogger uses removable Compact Flash memory
cards and can record for days or weeks with no operator
action needed.
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Simplicity: Corsa systems
are easy to install, configure and use. We designed our
systems to “plug and play” with sensors
and your vehicle.
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Durability: Wireless Corsa Data Loggers
are small, light, and very rugged. They are easy to install
and draw very little power from the vehicle.
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Flexibility: A wide range
of sensors and options are available. The EZ II Data Logger can
be connected to your own equipment as well as to standard
Corsa sensors. Analog, speed, thermocouple, and CAN signals
are all supported.
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Data Analysis: Use our
general-purpose data viewer, or save files in .CSV (comma
separated variables) format and bring them into almost
any data analysis package from Excel to MatLab to custom
applications.
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Customizable: We’d
be happy to discuss custom versions or additions to tailor
the system to your needs. Corsa firmware and software architecture makes
it easy to design to custom peripherals and different
versions at a reasonable cost.
What is a CAN bus? (Back
To Top)
CAN (controller area network) is a 2-wire communication
system used in many vehicles. Some engine control units
(ECU) will have a CAN output. CAN is used in some racing
fuel injection computers, and in most new vehicle applications.
The optional EZ-CAN module allows the Corsa Data Logger to record
any CAN messages, just as if they were from conventional
sensors. For instance, you could record engine RPM without
having to install another sensor since the ECU already broadcasts
an RPM message. If your ECU broadcasts messages for ignition
timing or fuel injection duty cycle, you could log that
data even though there’s no sensor that measures it
directly.
To use the CAN bus, you need to confirm that your ECU (or
other devices on the car) broadcasts CAN messages, and find
out what messages are available. Then it’s a simple
matter to set up the EZ-CAN to look for those messages and
record them. This will depend on what’s installed
on your vehicle, so call Corsa to discuss the details.
What is SAE J1939? (Back
To Top)
SAE J1939 is a standard for CAN bus communication, commonly
used on diesel trucks. The Corsa EZ-J1939 module supports
this standard. If your vehicle uses J1939, it’s easy
to record many different channels from the engine controller.
Engine RPM, injector duty cycle, commanded fueling, load
or throttle position, vehicle speed, intake temperature
and pressure are just a few common examples.
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