LD 200 gear ratios

[spitrans]

Hi, looking for a basic starting point on gear ratios for a formula ford on acb9 tyres
Thank you

[ydd]

Do you have the torque curve ?

If you do then it is possible to work out your gear ratios and ideal gear change rpm points - the latter I rarely see done.

Effectively you take the torque curve, the (driven) tyre size, the gear ratios and final drive ratios. You can then work out the torque at the wheels for any given road speed.

If you are starting from zero, you are going to want to try to get a gear ratio split that is progressive, and then use the final drive to offset this up and down the speed range to match the tracks and car characteristics (drag, mass etc)

I've a detailed post on my blog about this with all the calcs and a spreadsheet but can't post a link as I'm too new round here.

If you search google for "Guide to Optimum Gear Shift Points in Racing Car" then my blog (name in footer!) is fairly near the top.

It is likely you will be limited some where in this process - typically final drives and available gear box gears. However, with the spreadsheet you can at least determine the best compromise and quantify its effect.

Any questions or whatever, just ping back here and I'll try to help.