Simulated FJR vs C14 race

[UselessPickles]

Adjusting the final gearing has effects that surprised me a bit, but make sense now that I've seen it. Conventional wisdom is simply that lower gearing means more acceleration, but lower top speed (if you reduce the gearing enough such that top speed is now limited by redline rather than drag).

That's true to a certain point. In any given gear at any given RPM, you will always accelerate faster if you have lower final gearing. However, it does not have much of an affect on maximum possible acceleration beyond peak HP in 1st gear. The biggest change with lower final gearing is 1st gear acceleration. Hard to explain; maybe I can make a graph to illustrate later.

I finally created a nifty chart to help explain this here: https://www.fjrforum.com/forum//index.php?showtopic=142573

Just out of curiosity, are you doing it all in Excel? (The graphs obviously are.)

All the calculations are done in custom software that I am currently developing. I just dump the results out as CSV so I can put it in a spreadsheet and make charts.

 

[mcatrophy]

...

Just out of curiosity, are you doing it all in Excel? (The graphs obviously are.)

All the calculations are done in custom software that I am currently developing. I just dump the results out as CSV so I can put it in a spreadsheet and make charts.

I'm glad of that, I was thinking "How the h*ll does he do it in Excel?"

...If anyone wants more details about these calculations, I can show all formulas used

I would be interested, and in the software you are using to implement it all, thanks in advance.

 

[UselessPickles]

...If anyone wants more details about these calculations, I can show all formulas used

I would be interested, and in the software you are using to implement it all, thanks in advance.

Crap! I was using that as a scare tactic, but it didn't work on you

Is there anything in particular that you would like to know about the formulas involved? My "I can show all formulas involved" was originally related to calculating the drag coefficient from a known top speed, then calculating what the top speed could be if optimally geared for top speed. Is that what you want, or something else? I'm not going to just generally explain all formulas I used for everything, because that would take too long.

For example, here's explanations of the air density calculations that I used: https://wahiduddin.net/calc/density_altitude.htm

And SAE dyno correction: https://wahiduddin.net/calc/cf.htm

As for the software I'm using:

• Notepad++: Just a fancy text editor that does syntax highlighting for various programming languages and file formats.
  
• FireFox (the web browser).
  
• FireBug plugin for FireFox.
  

My code is written in javascript (all written by me). I currently have no user interface for anything. I have an HTML file that simply includes all of my javascript files so that I can load up the HTML page in FireFox and use the javascript console provided by FireBug to directly run various parts of my code with whatever parameters I want.

 

[mcatrophy]

...If anyone wants more details about these calculations, I can show all formulas used

I would be interested, and in the software you are using to implement it all, thanks in advance.

Crap! I was using that as a scare tactic, but it didn't work on you

I don't scare that easily.

Is there anything in particular that you would like to know about the formulas involved?

My "I can show all formulas involved" was originally related to calculating the drag coefficient from a known top speed, then calculating what the top speed could be if optimally geared for top speed. Is that what you want, or something else? I'm not going to just generally explain all formulas I used for everything, because that would take too long.

For example, here's explanations of the air density calculations that I used: https://wahiduddin.ne...ty_altitude.htm

Interesting.

And SAE dyno correction: https://wahiduddin.net/calc/cf.htm

A little easier.

As for the software I'm using:

• Notepad++: Just a fancy text editor that does syntax highlighting for various programming languages and file formats.
• FireFox (the web browser).
• FireBug plugin for FireFox.

My code is written in javascript (all written by me). I currently have no user interface for anything. I have an HTML file that simply includes all of my javascript files so that I can load up the HTML page in FireFox and use the javascript console provided by FireBug to directly run various parts of my code with whatever parameters I want.

Ah.

My background is as an electronics engineer (retired), always employed in areas that service turbine engines, so while I am not directly involved with airflow calculations, I am at least familiar with them and many aspects of mechanical engineering.

I was expecting you to have used either special purpose software, or something like Matlab, but using JavaScript makes sense, it means you have to do everything for yourself. Congrats.

At home I tend to use PHP for "real" programs or OpenOffice where appropriate, a simple example (I suspect all mine are simple compared with yours) of my PHP programming is in my gearing calculator (which agrees very closely with your rpm/mph ratio, mine says 75.46 mph @ 4004 rpm).

Thanks for the insight.