BASIC INSTALLATION AND OPERATION ISSUES
Question: DynoSim won't run and produces an error messge stating that a
.DLL file is missing.
Answer: Some Windows
installations do not have the correct versions of required dynamic-linking
library files needed for the DynoSim to operate properly. If you are using
the DynoSim and you've received a message indicating that a ".dll" file is
missing, download program updaters
the download is complete, double-click on the Updater to add the necessary
files and patches. If all else fails, upgrade Windows and make sure
Internet Explorer is installed and working (do not uninstall Internet Explorer
as this removes essential system files).
Question: Received an "Error Reading Drive D" (or another drive) message
when attempting to run or install the DynoSim. What does this mean?
Answer: This means your computer
cannot read the disk in your CD-ROM drive. The disk may not be properly seated
in your drive, the drive may be defective, or the disk may be damaged. If you
can properly read other CD-ROM disks in your drive, but the DynoSim
distribution disk produces error messages, try requesting a directory of a
known-good disk by entering DIR X: or CHKDSK X: (where X
is the drive letter of your CD-ROM drive) and then perform those same
operations with the DynoSim disk. If these operations produce an error
message only when using the DynoSim disk, the disk is defective. Return the
disk to ProRacing Sim Software for a free replacement (address at bottom of
Tech Support Form).
Question: Received a "Canít find E:\SETUP.EXE..." (or another drive)
message when attempting to install the DynoSim. What does this mean?
your computer cannot find the install files on the DynoSim disk your CD-ROM
drive. The problem is due to an outdated CD-ROM drive or driver software. You
can get around this program by creating a TEMP folder on your hard drive. Use
the Windows Explorer to copy all files from the DynoSim CD-ROM to the TEMP
directory (youíll need about 350MB of free disk space to complete this
process). Then run the SETUP.EXE file from the TEMP directory. When the
installation is complete, delete the TEMP folder.
Question: After installing the DynoSim (using Compact or
Custom install options) I am unable to access the DeskTop
Software Video files from the HELP menu in the DynoSim. I get a message
referring me to the Installation Guide or Users Manual. How do I fix this
Answer: Reinstall the
DynoSim from the CD-ROM. When you are presented with the three install
options (Typical, Compact, Custom) choose Custom. Then remove the check marks
from all files except the DeskTop Software Videos. Continue the installation
to reinstall just the Video files.
Question: When I tried to access the Users Manual from
the Help menu in the DynoSim, I get an error message that says that Adobe
Reader can not be found in the registry. How to I access the Users Manual?
Answer: You need to
install Adobe Reader on your system. Double click on the AR3W95.EXE (or
AR4W95.EXE) file located in the Acroread folder on the DynoSim CD-ROM. This
will install Reader (or go back to the support page to download the same
file). After installation is complete, you can open the DynoSim Users Manual
by selecting User Manual from the DynoSim Help menu or select Users
Manual from the Start, Programs, DynoSim Windows menus.
Question: Encountered "Could not locate the DynoSim CD-ROM" disk error
message when trying to run the DynoSim. Why?
Answer: Please insert the
DynoSim disk in your CD-ROM drive. Occasionally, the DynoSim will need to
access the CD. Please keep the DynoSim disk handy.
Question: The DynoSim produced an Assertion Failure error. What
should I do?
Answer: Please note down
all of the information presented in the message box, provide a quick synopsis
of what lead up to the error, include the version of your software, then send
this information to
ProRacing Sim Software. Thank you for your
assistance in helping us improve the DynoSim. Also, download program updaters
They eliminate several Assertion Failures.
Question: Everyone talks about how longer rods make more power. Why isnít
rod length one of the choices in the pull-down menus?
Answer: Tests we have
performed with the DynoSim show that rod length has virtually no affect on
power. We realize that many actual dyno tests have shown power increases, but
our simulation tests tell us that the power, when found, probably has little
to do with piston dwell at TDC (and the associated thermodynamic effects) or
changes in rod angularity on the crank pin. The measured power differences are
most likely due to a reduction of friction on the cylinderwall from changes in
side-loading on the piston. This can vary with bore finish, ring stability,
piston shape, the frictional properties of the lubricant, etc. These
variabilities are highly unpredictable. Some development, after all,
can only be done in the real world on a engine dynamometer.
Question: The DynoSim calculated the total Combustion Volume at 92ccs.
But I know my cylinder heads have only 75ccs. Whatís wrong with the software?
Answer: The confusion
comes from assuming that the calculated Total Combustion Volume
displayed in the component-selection screen is the same as your measured
combustion-chamber volume. The Total Combustion Volume is the entire volume
that remains in the cylinder when the piston reaches top dead center. See page
25 in the User Guide for more information about compression volumes.
Question: When I choose a carburetor that is too large for an engine (for
example 1200cfm on a 283 Chevy), why does the power increase without the
typically seen "bog" at low speeds?
Answer The DynoSim, along with
virtually any current computer simulation program, cannot model
over-carburetion and show the usual reduction in low-end performance that this
causes. In reality, carburetors that are too large for an engine develop fuel
atomization and air/fuel ratio instabilities, phenomena that is carburetor
specific and extremely difficult to model. The DynoSim assumes an
optimum air/fuel ratio regardless of the selected CFM rating. While the
program produces positive results from larger-and-larger induction flows (by
the way, this is not far from reality when optimum air/fuel ratios can be
maintained, as is the case in electronic fuel-injection systems), you canít go
wrong if you use common sense when selecting induction/carburetor flow
Question: The engine I am building uses two 660-cfm Holley carburetors.
How can I simulate the airflow?
Answer: The DynoSim will
simulate induction airflow from 100 to 3000cfm, rated at either standard
4-barrel pressure drop of 1.5-inches of mercury or at standard 2-barrel
pressure drop of 3.0-inches of mercury (a pressure drop of 1 inch of mercury
is equivalent to 13.55 inches of water). To simulate two, 660cfm, 4-barrel
carburetors, simply add the airflow and enter the total 1320cfm value into the
component-selection screen (make sure the pressure drop shown in the INDUCTION
category is 1.5-in/Hg).
Question: I am
working on some custom 2-barrel carbs. My buddy has a flow bench and has
tested some of my handiwork, but he used a pressure drop of 30 inches of water
instead of the "standard" 3-inches of mercury. Can I convert these flow
numbers to 1.5-inches of mercury so that I can test them in the Dyno?
Yes. Use the AirFlow calculator incorporated in the DynoSim version 3.08 and
later. Download program updaters
Question: I built a relatively stock engine but installed a drag-race
camshaft. The engine only produced 9 hp @ Sim rpm. Is this correct?
Answer: Yes. Very low
power outputs at low engine speeds occur when radical camshafts are used
without complementary components, such as high-flow cylinder heads, high
compression ratios, and exhaust system components that match the performance
potential of the cam. In fact, some low performance engines with radical
camshafts will show zero horsepower at low speeds. This means that if the
engine was assembled and installed on a dynamometer, it would not produce
enough power to offset any measurable load.
Question: The horsepower produced when I enter the seat-to-seat timing on
my cam card does not match the horsepower when I enter the 0.050-inch timing
figures for the same camshaft. Why are there differences?
Answer The DynoSim uses the
timing specs found on your cam card, and in cam manufacturerís catalogs, to
develop a valve-motion curve (and from this, develops the instantaneous
airflow for each port). Neither the seat-to-seat nor 0.050-inch timing figures
precisely describe actual valve motion; you would need to measure valve
position at each degree of crank rotation to come close to developing an exact
valve-motion diagram! Lacking this, the DynoSim "creates" its own
seat-to-seat valve-motion diagram for use in later calculations of power and
torque. A lot can happen in induction airflow between the time the valve rests
on the seat and when is reaches 0.050-inch of lifter rise. When in
doubt, use seat-to-seat timing figures. They provide the DynoSim more
information about valve motion at low lifts, and are more likely to produce
accurate simulated power levels.
Question: How does the DynoSim allow for hydraulic, solid, and roller
Answer: The DynoSim
calculates a valve-motion diagram that is used in subsequent calculations to
predict horsepower and torque. When the choice is made to move from hydraulic
to solid, and then from solid to roller lifters, the DynoSim increases the
valve acceleration rates to coincide with the lobe shapes that are commonly
found on these cam grinds. See pages 53 in the User Guide for more information
about lifter selection.
Question: Can I change rockerarm ratios with the DynoSim?
Answer: Yes. Simply use
this formula to alter valve lift (the DynoSim will calculate the new valve
motion throughout the lift curve):
New Lift = Old Lift x -------------
When you have calculated the new valve lifts
for the intake and exhaust valves, enter these numbers directly into the
component-selection screen (make sure Auto Valve Lift is turned off).
Question: I found the published factory seat-to-seat valve timing for
Pontiac engine that I am building. The IVC occurs at 112 degrees (ABDC).
Something goes wrong when it enter the valve events into the DynoSim.
Answer There are so many ways
that cam specs can be described for cataloging purposes that itís confusing
for anyone trying to enter timing specs into an engine simulation program.
Your Pontiac is a classic example of this lack of standards. The Pontiac cam
listed in the factory manual is a hydraulic grind with seat-to-seat timing
measured at 0.001-inch lifter rise. Because the cam is designed for long life
and quite operation, it has shallow opening ramps. This is the reason for the
large number of crank degrees between the opening and closing points. In fact,
during the first 35 degrees of crank rotation, the lifter rises less than
0.010-inch. If this wasnít the case and the valve opened and closed at the
specified timing points listed in the factory manual, the cam would have over
350-degrees duration, and itís unlikely the engine would even start! The
DynoSim can use 0.004- or 0.006-inch valve rise,
0.007-open/0.010-close valve rise, or even 0.020-inch lifter
rise for seat-to-seat timing. But the 0.001-inch lifter-rise figures published
in your factory manual are useless for engine simulation purposes.
Question: My cam manufacturerís catalog does not list seat-to-seat
valve-event timing. But it does list seat-to-seat intake and exhaust duration,
lobe-center angle, and intake centerline. Can I calculate the valve-event
timing from these figures?
Answer Yes. Use the Cam Math
Calculator built into the DynoSim to calculate the intake and exhaust
opening and closing points. Youíll need all of the following information:
- 1) Intake Duration
- 2) Exhaust Duration
- 3) Lobe-Center Angle (sometimes
called lobe separation angle).
- 4) And the Intake Centerline Angle.
- See the User Guide for more information on
the Cam Math Calculator.
Question: I have been attempting to test camshafts from a listing in a
catalog. I can find the duration and lobe center angle. The cam manufacturer
wonít give me the seat-to-seat timing (they act like itís a trade secret). Can
I use the available data to test their cams?
Answer: No. As stated in
the previous answer, you also need the intake-center angle to relate cam lobe
positions to TDC and, therefore, crank position. Freely providing seat-to-seat
timing or any of the other cam specs used in the DynoSim poses no threat to
any cam grinder. It takes a lot more than valve-event timing to manufacture a
quality cam; full profiles of the lobes are needed to ensure mechanically and
dynamically stable operation. Cam companies that refuse to provide potential
customers with simple valve-event information for evaluation in programs like
the DynoSim are simply living in the "dark ages." Our suggestion is to
contact another cam manufacturer.
RUNNING A SIMULATION
Question: The DynoSim displayed an error message "The DynoSim was unable
to complete the simulation. A more balanced combination of components..." What
Answer: The combination of
components you have selected produced a calculation error in the simulation
process. This is often caused by using restrictive induction flow on
large-displacement engines, using a very short stroke, or by using radical cam
timing on otherwise mild engines. Try reducing the EVO timing specs,
increasing the induction flow, lengthening the stroke, selecting a cam with
less duration, or reducing the compression ratio. A balanced group of
components should not produce this error.
Question: The DynoSim Iterator takes several seconds to complete one
cycle of a several-thousand run test. A full series takes way too long. Is
there a problem with my computer or the software?
Answer: The DynoSim is a
full 32-bit highly optimized program, however, it uses a powerful full-cycle
simulation that performs millions of calculations for each point on the power
curves, and this takes some time. Refer to pages 7 and 8 for more information
on computation times for several computer systems.
Question: I have tried many different engine combinations using the same
engine displacements and have noticed that several of the power curves begin
at nearly the same horsepower and torque values at Simrpm. Why are they so
similar at this engine speed?
Answer: Since the DynoSim
uses a simulation technique that iterates toward an answer this is different
from built-in Iterative Testing the first power point must be developed based
on educated "guesses" about mass flow and other variables. The next point, at
2500rpm, is calculated from the starting point, plus the data obtained from
the completed simulation, so accuracy is higher. By 3000rpm, the power points
are based on simulation calculations with virtually no remaining influence
from the initial estimations.
Question: When I run a simulation, part of the horsepower and torque graph
doesn't appear on my screen. What can I do to correct the display?
Answer: Open the Graph
Options menu (right-click on the graph) and select Auto Range for the
Y1 or Y2 variable. See the User Guide for more information about
graph scaling and plotting variables.
Question: While using the Iterator, II specified a 30-degree
range of values for IVO cam timing with 5 degree steps. But the number of
steps displayed is zero. Whatís the problem?
Answer: Always specify the
lower (smaller) number in the left range box and the higher number in the
right range box. The Iterator increments the left-box value with the
step value until it reaches the right-box value.
If you havenít found an answer to your problem
Sim Software provides technical service to registered
users only. If you haven't already,
your software today). We will review your problem and
return an answer to you as soon as possible.