The underlying concept behind this program is the vehicle. While the name implies that it is solely used for selected transmission gear ratios, this can not be done properly without taking the entire vehicle into consideration. The same ratios might not be appropriate for vehicles with different engines or weights so we have gone forward and used all this information to help you select the proper ratios for optimum performance. With this concept in mind it does have to be understood by the user that you do need all this information about your vehicle in order to get the full benefit of this software. Ideally you need to know the vehicle weight, area and Cd. You should also have a dyno sheet for the engine that shows either the torque(preferred) or horsepower for the engine over the intended rpm range you are interested in using with this software. These torque and horsepower numbers need to be corrected to sea level, something that most modern engine dynamometers will do for you automatically via the software included with the unit. Any information you have on the existing transmission is also helpful as a starting point. Sample engines and transmissions have been included as examples are not guaranteed to be a usable example for your vehicle. These entries are for demonstration purposes only!

Organization

The program is comprised of several databases with some samples to play with and to add your own vehicles. These databases will hold tens of thousands of records so feel free to keep trying different things and is ideal for someone that has to maintain many racing cars at different venues.

Intended audience

This software is designed for road racing, and road going vehicles as a primary audience. There is further information on terminal speeds that would be of interest to teams building vehicles for land speed record attempts. There is a lot of information that is useful for drag racers but the software is not optimized for that venue and no attempts have been made to come up with 60 ft times and quarter mile elapsed times. The reason behind this small limitation is there are no efforts taken for a standing start as most racing vehicles do not consider the time it takes to get from a standing start to some minimal speed to be of any consequence other than drag racing. All the information on torque curves and power applied to the wheels would be of equal value to a drag racer as well as anyone else interested in the overall performance of their vehicle.

Hardware requirements

This software will operate with the system requirements listed below. Be advised we offer no tech help in setting up your PC, please call your dealer for this information.

Processor Intel Pentium or better

Memory 32 meg or more

Screen resolution 1024 X 768

Color True 32 bit color suggested

Operating system Windows 95b or greater

Registration

This software is copy protected and will need to be registered to run.  The easiest way to do this is to use the "Registration" menu selection under the help menu. This will compose an e-mail to the tech department with your User Name and Machine ID number. Do not edit any of this information unless instructed to do so as it will make getting a proper unlock key virtually impossible. Please send this to us and add at the bottom of it your full name and address and the date and number of the check being sent in the amount of $79.95 payable to Engine Management Systems, 2 Ashby Street, Mystic,CT. 06355. Please put a copy of your e-mail with the check as well to help keep our records straight. You will then receive a temporary key via e-mail that will be good until your check clears at which point to will receive the permanent key.

Updates

Updates will be available to registered users on the Engine Management Systems web site. A direct link to the site is in the software.

Contacting EMS

There is a "contact" menu selection Item in the "Help" menu.  Please use this to contact us directly with any questions or comments concerning this software.
 

Program

Basic navigation

This software is windows based and makes a lot of use of standard windows features to make the use simple and familiar. The pull down menus work as they would in all standard Windows based software. Drag and drop is also employed in the Gear Manger software that is included.

The various databases also use a standard method of entering and updating information. They all have the same database navigator tool bar that is associated with the table being accessed. They have standard Windows 'fly over' hints to refresh your memory as to their proper use as well as what is listed here.

From left to right these are the actions associated with the Navigator buttons.

Button Action

Go to First record in database

Go to Previous record in database

Go to Next record in database

Go to Last record in database

Add a record to database

Delete a record in database

Update a record in database

Post changes in database

Cancel changes in database

Refresh database

All complex software has some bugs. There are no known major ones in this release. If you find any please let us know about them and do document them thoroughly. Having a different opinion of what might happen under a set of inputs is not a bug it is a difference of opinion unless you document it completely with known good data that encompasses all the database entries as you may have some entries that you made assumptions with and therefore all bets are off as to the final results. If you have any printing problems they are all generally related to printer drivers.  There have been some issues with printing to a network printer as well.
 
 

Main screen

The main screen of this software has many things to offer. The first and most obvious is the graphs of all the shift points along with the torque at the wheel and the required torque (road load). Pay attention to both the shape of the plots for torque as well as the numerical values for the torque. Understand that the plots in this chart are limited by both screen resolution and to a lesser degree rounding errors along with any assumptions that have been made by the user about the values of the entries that have been used to describe the vehicle. The better the information that goes in the more accurate the information that comes out.

In the Torque in column you will see if there is a torque spike during a gear change by the color of the entry. Red indicates that the torque in the next gear is greater than the torque at the end of the previous gear. The magnitude of this change is for the user to decide what is tolerable in their own chassis setup. With that said I would be somewhat more cautious in a traction limited vehicle and want these spikes at a minimum, but it may or may not be faster around the race track with a different setup. In essence this software supplies you with a lot of information but in the end it is to the user to decide what things are valid to their particular combination and what items are not of any concern.

Also displayed here are most of the entries for the vehicle that has been loaded into the software. At this point it is easy to try different engines, transmissions, shift points etc until the desired results are obtained.
 
 

Databases

Vehicle

The Vehicle database encapsulates the concept behind this software and all of the entries have to be filled in with valid data in order to get a series of plots. It will not calculate on partial data. As you can see this is where all of the details are stored and where you can build your vehicle or start with an existing one and modify it to suit your uses. At program start up generally you would load a vehicle into the program form the file menu. You can alternatively open each database and define your vehicle as to engine, chassis, transmission, and venue. At that point open the vehicle database and add a new record to it with the name of your vehicle and pick the engine, chassis, transmission and venue that you have created. You can then fill in the data about tires, ring and pinion, acceleration limits, nitrous if used and shift points. Currently this is the only place to add the nitrous information so if you want to experiment with when it is activated you will have to open the vehicle database make your changes and save them, at that point just click the load button to make your changes take effect in the software. There are currently no entries that describe the turn on characteristics of the nitrous stages. This could lead to some misleading results in the torque in column , most notably there may be some spikes that show up in read that have no bearing on what would happen in real life. This difference is caused primarily with line lengths, bottle pressure and jet sizes. There are a myriad of variables to consider the turn on time besides these few variables and we chose not to try to predict them for this reason. As a guideline once in use if you would like to soften the hit add length to the nitrous line between the solenoid and the jets.

There are two more things that do need to be mentioned. Pick a name for the vehicle that is descriptive, ex. MWE F500 Atlanta. Do use the notes section at the end to describe any important features of this setup. With a sports car you will probably have a different setup for each track that will effect the entries for transmission, venue and shift points. A drag race car would more likely have different nitrous settings, and a road going car would tend to become static unless the engine was changed or anything else that would redefine the vehicle.

Chassis

This database contains information about the chassis. Information needed is the weight, cross sectional area and the Cd for aerodynamic considerations. The weight is in pounds and is the total weight, corner weights are not necessary for what we need to get done here. If you have corner weights just add them up and if you are unsure about the weight it can be found in several ways. Easiest is to see if it is published, next is to go to a truck weigh station and see if they will check it for you. Another alternative is to go to anyplace that they sell things by the truckload by weight. Obviously the more valuable the commodity they are selling the more likely the scales will be very accurate. Cd numbers can be found in a variety of ways. If you have a very popular vehicle they are probably published either by the manufacturer or on the web in a special interest group that races what you are racing. If these places turn up no clues and you have no idea what the Cd might be for your vehicle there are a few mores ways to find a suitable value. Remember that anything that gets in the air stream makes the number generally larger and creates more drag. Also anything that generates down force will have a drag penalty as well. Open cockpit cars also have more drag as well but there may be exceptions for all these rules.

In the broadest terms these numbers are a start…

Sedan 0.35 to 0.50

Sports Car 0.29 to 0.40

Roadster(ex 32 Ford) 0.40 to 0.65

Open wheeled sports car 0.40 to 0.80

Bonneville streamliner 0.17 to 0.25

Here is a sample of what the chassis database screen looks like… as you can see you can name the chassis anything you want that is meaningful to you.

Engine

The engine database contains information about the torque output of the engine at various operating speeds. Anything from 2500 rpm to over 14000 can be input in 500 rpm breakpoints. If you know the horsepower at a given rpm but not the torque just right click on the form and a torque calculator will pop up to give you a hand getting the correct number entered. These values also need to be corrected torque numbers, these are typical of what a manufacturer would quote or what comes off an engine dynamometer. There are also a few sample engines that are included so you can get a feel as to what it should look like when you are done entering the correct values. You do need as many values as possible as the program will not calculate anything for an rpm that you do not have any information about the engine torque.

Most engines have a relatively smooth torque curve that goes from a lower starting point to the torque peak and then tapers off to a value of approximately 15 to 20% less than the peak torque when you reach peak horsepower. Exceptions to this are engines with mismatched components such as headers and intake systems or camshafts that just make no sense compared to the other parts that are included in the engine build. As a side note to this problem you have to remember that for the engine to be useful it does have to fit in the chassis. This may cause some problems with the torque curve as the headers that you should be using or the intake manifold system that is optimum will just not physically fit in the chassis. Another notable exception are small displacement turbo charged engines. The Ford Probe GTP engine is used as an example of this phenomena, you can see plainly that the engine goes from 200 ft/lbs. to 400 in about 1000 rpm. This is due to the engine coming up on boost very rapidly. It goes from almost no boost to 28 lbs. in that short spread of rpm and will place some serious demands on transmission gear selection and driver ability to stay in the "sweet spot" of engine operation. These are ideal situations to take advantage of this software to optimize the gearing using a "total vehicle approach" rather than just a gear chart to select transmission ratios for the vehicle. If you find that it seems to be impossible to select the proper gearing then it might be time to have a serious talk with you engine builder or cam grinder to discuss the ability to add some area under the torque curve and find out from them what sacrifices would have to be made in other areas. You can then create an engine with these proposed changes and see if the overall performance of the vehicle improves to a point that the changes are worth while.

Torque Calculator

This handy little calculator is part of the engine database screen. A right click on the mouse will bring up this window to calculate the torque from a known rpm and horsepower, you can then insert the value into the appropriate rpm column.

Transmission

The transmission database is the one that you will store transmission data and combinations that have been worked out already. It is advisable to give them an appropriate name that will help you identify them as to the use intended. A typical name might look like "Buick March Hew DB Atlanta" there is an application notes area that you can enter other data such as the date and possibly the name of the file downloaded from the data acquisition system. Lap times or any other special notes that would make you pick this transmission for another project might be another use.

When entering data into this data base remember that to limit the number of gears in the transmission all that needs to be done is to use the same ratio for all gears above the last one. An example of this shown below is the "t 10 A" it is a four speed transmission and the software will ignore fifth and sixth gear entries because they are the same as fourth gear. The only other thing to keep in mind is the ratios need to be continually decreasing. An entry of 1.00 for third and 1.25 for fourth will produce undermined results and is not a combination that would be expected to be found in a real life situation.

Also please note there is currently no support for torque converters in automatic transmissions so all data and examples use manual transmissions only. There is also no support for slider type clutches that use counter weighted levers to adjust the amount of lock up as they are not commonly used by the target audience of this software.

Venue

The venue database is very straight forward in what it holds for information. In this current release there are only 2 entries used, the Air Density and the Surface Cf. Later releases will calculate air density from the other entries. The air density entry will have an effect on the aero portion of the road load and also change the available torque to the wheels due to changes in engine power production. The Surface Cf is of worthy of some discussion in its own right but for this exercise I will offer some guidelines that should help to determine the appropriate value. It does have a large effect on the road load of the vehicle but is unfortunately a tough one to predict with absolute certainty. To begin with as the numbers get smaller the surface is deforming more and absorbing more torque rather than using that torque to move the vehicle forward. If we leave out the concept of driving in quick sand then the worse would be beach sand that would have a value around 0.2 to 0.3 the best would be concrete that I would assign a value of 1.0 as I doubt if you will find anything harder that is commonly used a paving medium. Other notable entries that are common would be asphalt at about 0.8 to 0.95 and the various dry salt lakes that can range depending on surface conditions from a 0.5 to a 0.75 value. Most other surfaces can be fairly easily interpolated using these basic guidelines.

There are things that can make the Surface Cf numbers incorrect and is worth discussing. The definition involves the deformation of the road surface, there are many special cases that can throw these values completely out of normal ranges. The type of tire used is the first and the weight of the vehicle is the second when you get to the regions of small numbers. What is really boils down to is the unit loading between the road surface and the tire. As this increases you will have a larger deformation of the surface and get a lower number than initially calculated or if this decreases the number will get larger as the surface deforms less. A fine balance needs to be reached between unit loading and the surface area of the tire along with the associated side wall flex of the tire. These relationships are easily shown with a worst case scenario. Consider a surface of beach sand and a vehicle that weighs 5000 lbs. If you fit this vehicle with tires that are 18 inches wide with soft side walls it will sit on top of the sand deforming it very little due to the low unit loading. The downside to this is the side walls will flex and there will be some aero losses as well at higher speeds due to the width. Now take the opposite situation fit this vehicle with 2 inch wide steel wheels. These will sink deeply into the sand and deform the surface greatly. If you could get this vehicle to move the aero losses would be low and the side wall flex zero unfortunately it probably would not move.
 
 

Gear Manager

The Gear Manager is a database that holds many transmission families that share the common feature of having a myriad or ratios available for each position. On the top section of the screen you can select the family of transmission that you want to work with, you can obviously add your own as well. Also on the top section are a set of filters that you can use to help narrow down the choices of gears. many of these transmissions have separate subsets of gears that will only fit in certain positions with first and second being the most typical situation to have a separate set of gears dedicated to those positions. You can also filter on whether you have the particular gear set or if it is even available. The filter option for "Position" uses drag and drop technology that allows you to just drag the value for position used and drop it in the position filter box or you may type it in but it is case sensitive and spelling does count here.. This also applies to the "Ratio" entry as you can drag and drop the ratio into the main form while you are selecting and evaluating different combinations.

The column entries of "On Hand" and "Available" are useful to help keep track of what gear sets you own and the ones you might want to purchase in the future if they show an increase in performance. The "Driving Gear" and "Driven Gear" columns are there to help you identify the gear sets are they are customarily labeled in that fashion. You will seldom see a label that says you have a 2.111 ratio, but will most likely encounter a label that reads 18/38 for the particular gear set.

Graphing

There are additional graphs that are very useful other than the main one showing Rpm and Torque. There are graphs for both acceleration vs. speed and time and distance vs. speed. These graphs have a wealth of information in their own right and are worthy of some careful scrutiny while working on setting up a transmission to properly suit a vehicle and particular race track.

Keyboard shortcuts

The acceleration graph shows three items, the "Acceleration limit" that you put in when describing the vehicle, the road load that was calculated along with the calculated acceleration rate. Optionally if you have selected "Show gear change markers" in the main graphing setup they will be carried over to this set of plots as well. When the acceleration has gone to 0 you have reached a terminal speed and when it is over the acceleration limit that you have decided on you are probably spinning the wheels to some degree. These areas ( slip and spin) are not further evaluated in this plot and it is left to the user to understand these issues on their own. The shape of the acceleration plot will mirror the composite torque curve very closely and help identify what might happen with the torque spikes if they are present and to what degree they could upset the handling of the vehicle.

Time and distance

The time and distance graph has some interesting things that can be put to good use. The most obvious is to determine if the car is geared correctly overall. This can be observed in a couple of different ways. In a road race car if you know the speed and gear you exit the corner just before the longest straight you should be able to get a good picture from the plot as to what your speed will be at the end of the straight. If you have a lot of rpm left to go in high gear then you are possibly running too tall a gear for this particular race track, conversely if you have reached a terminal speed before the end of the straight the you might want to take a little gear away so that you reach a higher speed on the longest of straight sections. Another interesting use would be with a land speed record attempt, you can see if you will have enough race track available to reach terminal speed and adjust the factors involved to reach the fastest speed in the available distance. This graph does take into account the "Acceleration Limit" entered in the Vehicle database and whenever the acceleration rate is greater than the acceleration limit the software will use the acceleration limit instead of the calculated values.