.car spreadsheet calculator

[Tomte]

Hello guys,

Don wrote a lot of nonsense about 'Tomte physics' and such... Of course, I didn't create any physics, I just merely made up a spreadsheet which allows to calculate some of the .car data from given specifications and 3D model data. The spreadsheet follows my personal logic, therefore it might not be very clear to understand. I'm an engineer, I'm into formulae, not into GUI...
The spreadsheet evolved slowly, from time to time got updated to include more calculations, based on discussions with members of the community (thanks to all involved, especially to c14ru5, Brook, Giles, Don, Val, theSnail).

This work is in no way meant to replace Brook's excellent dotcar editor, they can be used hand in hand. Of course, it would be most practical to include my calculations into Brook's editor, but I don't know if Brook is still around...

The latest version got a tiny graphical overhaul. All the calculations are now on the first sheet, the second sheet contains specific sections of a typical .car file using values from the calculations of the first sheet.

In order to use the spreadsheet, you either need a google account, Excel or OpenOffice. When you click on the link below, you will access the original spreadsheet, which is locked. In the (google) menu, you click File/Make a copy (if you have a Google account) or File/Download as... (if you use Excel or OpenOffice).

If you want to get some meaningful results, you will need to enter data into ALL the grey and blue fields ON THE LEFT of the first spreadsheet. The data on the right (aero/inertia/wheel size/positioning/friction...) will be calculated from the fields on the left.
It is imperative that you know how to measure certain positions/dimensions on the cars 3D model (axle placement and offset etc...)

The 'Torque and Power Check' table tells you if your engine specs follow the logic of torque and power. You probably saw me positing several times that certain bhp figures do not work at a specific rpm with a given torque... well, this is the calculation to check it. The idea is that your engine cannot produce more torque at max power as it stated for max torque.
As long as the Check field below 'Torque at Max Power' is green and says "OK", you're good. If not play around with it or ask me.
Same goes for the 'Power at Max Torque' check.

The power and torque values in this table are also used in the wheels.friction calculation, so it is necessary to enter these together with the top gear and final drive ratios.

If you happen not to have power or torque in the Redline format (i.e. Watt and Newton Meter), there is one translator for each value. You can use German PS, bhp or kW for power and Nm (obvious....) and lb-ft for torque. The power values here are used to calculate the wheels.friction, so it is important to enter these. The valus from the translators are not linked to the 'Torque and Power Check' table, as I don't know what are your base values.

Now, enough of this, here you go:
.car specs spreadsheet

EDIT
----
I just found out that my (French) version of Excel and OpenOffice do not seem to like the rounding command on the second page (inertia, power and wheels.friction lines). I wonder if it is the same at your end in case you are using a non-English version. Just to be clear, the calculations on page 1 are not affected, only the .car sections on page 2!

The google-spreadsheet is not affected by that.

[DonaemouS]

one question about the car configutaror.

Is any chance to have the standardize those values as well?

Code:

engineInertia x
engineBaseFriction x
engineRPMFriction x

I remember I read somewhere that those values depend from the engine "capacity" (aka liters) Is there any other infos we should to know before placing random numbers?

[Tomte]

one question about the car configutaror.

Code:

engineInertia x
engineBaseFriction x
engineRPMFriction x

I don't have any insight about engine inertias. I believe it has a lot to do with the material used, the number of cam shafts, balancer shafts, weight of the clutch plates, weight of the (one part or two part) fly wheel... everything that rotates in an engine.
The base friction settings are dependent on the number of pistons, valves, bearings, engine configuration, basically everything that moves longitudinal or that rotates.
EngineRPMFriction should be dependent on displacement, compression ratio, maybe rpm?

All in all, I don't know enough about it. I don't think that from the 4 values we know about engines we can determine all that.

Next thing you ask is to automatically calculate the suspension settings... no no no, there must be some creative work left for the plugin developer.

[Tomte]

Ok, screw Excel and OpenOffice... or Google's export function. On the page with the .car file sections, I used a rounding operation in order to avoid something like

Code:

Power 192357.12388463

. Apparently, the round command is either not exported properly or Excel/OO do not properly interpret it. Furthermore, there seems to be a problem with the cell reference.

None of the calculated values on the page 'Redline .car calculations' is affected, all works as it should be here. So if you want to use the .car code snippets, you need a Google Account.

[NoNameBrand]

Time to start playing with this.

[DonaemouS]

Time to start playing with this.

Welcome Back!!!

[Sponsored content]