Friday, December 10, 2010

A lap around Martinsville

Ladies and gentlemen - holy fuck, we've done it. Some upbeat tunes are in order. If you're not a fan of my tunes, well, that's why this is my blog and not yours.
Allow me to show you a 30.1 second lap around Martinsville:
Right about now you may be saying to yourself, "Daaaang homie, that shit is fly." Alternatively you might be saying, "Well that looks fuckin' dumb." You'd be correct either way. It's a dinky little short track, it's not gonna look very cool. Also, admittedly, a 30 second lap at Martinsville is pretty damn slow! Cup cars (NASCAR) get around in under 20 seconds. However, my numbers for drag, downforce, tire grip level, and gearing, are all arbitrary. Also, my "driver" doesn't trail brake nor ease into the throttle, so again - absolute numbers are BS.

Believe it or not, for weighing literally over one ton more than a F1000, Cup cars also have a better power to weight ratio. A 358 ci (5.9L) V8 turning over 9000 RPM will do that!

Still got some stuff to check out to make sure everything looks legit, and then I can start breaking down a road course and seeing what it comes up with. Will have to see if I can dig up some actual F1000 DAQ at some racetrack to back-calculate appropriate numbers for drag, downforce, and mechanical grip. But for now... I'm catching up on Mad Men.

1 comment:

Jersey Tom said...

There is no driver model, as there doesn't need to be one :) Keeping things simple for now. Instead of a closed-loop feedback sim that follows a path.. it's more of a 'segment analyzer'. Track is defined by a list of segments (corners and straights), each with an associated radius and/or length. It then steps through each segment and basically just adjusts braking points and corner speeds until all the 'rules' are met (namely that speed trace has to be continuous and you can't exceed the cornering grip limit).

Really pretty straightforward, and I'd say I probably have less than 8 hours in the whole thing. Hour or two a night over a handful of nights. If someone wanted to write their own version of this, shouldn't take more than a work day!

Will post up some more interesting plots tomorrow when I break down Road America and start playing with parameters.. lateral vs longitudinal grip, etc.