Well guys, i have figured out how to accurately graph the power of the cars in LFS. Not sure if anyone else has done this yet, but here we go.

Here are the first two "Dyno" Graphs i have made for the XRG and XFG.

Theres an equation i found in one of my physics books that relates gforce to torque. I attempted to join this with another equation that related gear ratio, final drive, and weight to feet/second. Combining these equations, and with a bit of reading, i was able to come up with this equation....

(A)

(Gear Ratio x Final Drive Ratio x 0.85)

(B) (Driving Weight x Rolling Radius(ft))

Torque= A x B

Now lets apply that to making Dyno graphs for the cars in LFS....

Now that you know the contents of the equation, lets go through the procedure.

First off, take out a peice of paper (unless you want to apply the data directly to excel), and make a table; 3 columns wide, left side RPM, middle is Torque, Right side is Horsepower. In the RPM column, start at 1000rpm and list down the line in 500rpm intervals until you reach the car's redline.

Secondly, for those of you without a clutch pedal, make sure you DISABLE autoclutch so that you can retreive torque readings below 2200rpm.

Lets start with the XFG. The XFG weighs 2231lbs with 1 driver and 5% fuel. The Rolling Radius of the wheels is equal to about 1 foot. As a control, i use the (Hard track) settings for every test. This means the gearing is pretty much standard. Open up Drag Strip.

The first test point will be 1000rpms. Accelerate up easy. 3rd gear is good for this car for this test. My 3rd gear ratio was 2.180 with a final drive ratio of 3.20. Get in to 3rd gear and slow down until the engine is revving at about 800rpm. Mash the gas and watch what the geforce meter reads as your engine hits 1000rpms. Do this a few times in order to get an average accurate reading. In my tests with the (hard track) gearing, 3rd gear at 1000rpm full throttle yeilded about 0.155g's. Lets plug this into our equation.

(A)

(2.180 x 3.20 x 0.85)

(B) ( 2231 x 1 )

A x B =

Now, in order to convert to horsepower, all you do is the following....

HP = (Torque x RPM) / 5252.... So (59.59 x 1000)/ 5252 =

So , as you begin cussing at your XFG for its pitty of an automobile, you mark this down on the table. Then you will do the same exact thing, but test at 1500rpm. Then 2000. and so on....

After you get your full table of data with torque and horsepower, open up Microsoft Excel. In the left column, starting at 1000, list the RPM's in 500rpm intervals going down until you reach the redline rpm (just like you did for your data table on a peice of paper). Then the next column list the Torque numbers corresponding. Then the Horsepower numbers in the next column. Then, click on the Chart Wizard icon. Set series 1 as horsepower and series 2 as torque. Assign the horsepower series with an X value of RPM and the Y value of your horsepower numbers. Do the same for the Torque Series and torque numbers. Then you will select a Line graph, the first one. It will plot your dyno graph. Add titles and labels as you wish.

And thats it guys!!! Keep in mind, these numbers are actually power to the drive wheels (so they will not necessarily match the power information in the Info tab in the garage). I think someone should be able to make a program that automatically calculates everything using the information i provided. Unfortunetly, i dont have those skills!!!

Enjoy!!!

-HK-TheStig

http://www.hkracers.com

Here are the first two "Dyno" Graphs i have made for the XRG and XFG.

Theres an equation i found in one of my physics books that relates gforce to torque. I attempted to join this with another equation that related gear ratio, final drive, and weight to feet/second. Combining these equations, and with a bit of reading, i was able to come up with this equation....

(A)

__(Gforce)__(Gear Ratio x Final Drive Ratio x 0.85)

(B) (Driving Weight x Rolling Radius(ft))

Torque= A x B

Now lets apply that to making Dyno graphs for the cars in LFS....

**Gforce:**Press F9 in-game and you will see Lateral and Longitudenal G-force information displays under the steering meter. This is a key tool.**Gear Ratio x Final Drive:**You can do these "dyno runs" in any gear, however it is easier to test in a higher gear so that the rpms do not jump up very quick. Take the Gear ratio of the gear you are in and multiply it by the final drive ratio.**0.85:**Just a mathematical constant used in the equation.**Driving Weight:**This is the weight of the car + driver + whatever fuel you start with. Make sure when you factor in this weight in the calculations, that you click on the__Driver__and__Fuel__tabs on the left in the garage to add those items to your race weight.**Rolling Radius:**Knowing wheel specifications of each car is important. The rolling radius is half the diameter of the whole wheel (center of wheel to end of treds). (NOTE: Visit this website http://www.carbibles.com/tyre_bible.html and scroll half way down. There is a Rolling Radius calculater on that page, giving you the Rolling Radius in Millimeters. You then will need to convert this to inches, and then to feet. An easy way to do it: Take that RR number and put it in the "mm" box on this website: http://mg-jewelry.com/mmtoinches.html . This will give you the RR in FEET).Now that you know the contents of the equation, lets go through the procedure.

First off, take out a peice of paper (unless you want to apply the data directly to excel), and make a table; 3 columns wide, left side RPM, middle is Torque, Right side is Horsepower. In the RPM column, start at 1000rpm and list down the line in 500rpm intervals until you reach the car's redline.

Secondly, for those of you without a clutch pedal, make sure you DISABLE autoclutch so that you can retreive torque readings below 2200rpm.

Lets start with the XFG. The XFG weighs 2231lbs with 1 driver and 5% fuel. The Rolling Radius of the wheels is equal to about 1 foot. As a control, i use the (Hard track) settings for every test. This means the gearing is pretty much standard. Open up Drag Strip.

The first test point will be 1000rpms. Accelerate up easy. 3rd gear is good for this car for this test. My 3rd gear ratio was 2.180 with a final drive ratio of 3.20. Get in to 3rd gear and slow down until the engine is revving at about 800rpm. Mash the gas and watch what the geforce meter reads as your engine hits 1000rpms. Do this a few times in order to get an average accurate reading. In my tests with the (hard track) gearing, 3rd gear at 1000rpm full throttle yeilded about 0.155g's. Lets plug this into our equation.

(A)

__(0.155)__(2.180 x 3.20 x 0.85)

(B) ( 2231 x 1 )

A x B =

**59.59 ftlbs torque @ 1000rpm**... illepallNow, in order to convert to horsepower, all you do is the following....

HP = (Torque x RPM) / 5252.... So (59.59 x 1000)/ 5252 =

**11.35 HP**So , as you begin cussing at your XFG for its pitty of an automobile, you mark this down on the table. Then you will do the same exact thing, but test at 1500rpm. Then 2000. and so on....

After you get your full table of data with torque and horsepower, open up Microsoft Excel. In the left column, starting at 1000, list the RPM's in 500rpm intervals going down until you reach the redline rpm (just like you did for your data table on a peice of paper). Then the next column list the Torque numbers corresponding. Then the Horsepower numbers in the next column. Then, click on the Chart Wizard icon. Set series 1 as horsepower and series 2 as torque. Assign the horsepower series with an X value of RPM and the Y value of your horsepower numbers. Do the same for the Torque Series and torque numbers. Then you will select a Line graph, the first one. It will plot your dyno graph. Add titles and labels as you wish.

And thats it guys!!! Keep in mind, these numbers are actually power to the drive wheels (so they will not necessarily match the power information in the Info tab in the garage). I think someone should be able to make a program that automatically calculates everything using the information i provided. Unfortunetly, i dont have those skills!!!

Enjoy!!!

-HK-TheStig

http://www.hkracers.com