We've all had that argument about whos line is correct. Some say corner 2 is a double apex. Others swear that it is one. The Carousel? Namerow? The Key Hole? Who's line is right?

Forget about racing for a moment. Let's assume you are lapping or qualifying and you don't have to defend anything.

Does am M3 really need a different line than a GT3? What do you think?

The driving gloves come off....

I noticed and Ross Bentley confirms in one of his books (more secrets for pro drivers?) that fwd cars need to apex a tad later because when they get on the power they understeer more than rwd cars. At my first real event in my new fwd mini my instructor told me that I could apex extra early in my fwd car. It wasn't super slow but I corded 4 brand new michelin pilot sport 2s in 2 1/2 days. Waiting that extra 1/2 second to get on the power made all the difference.

Part of the problem you are going to have with answering this (loaded) question is to define what the "line" is. Is it where your car feels the best thru the corner, or is it where it will barely hang on and shreds the tires and brakes, to get the fastest time thru the corner and best exit speed? Obviously a data logger would help to determine these things, but without that information at hand, other measures lead me to say that yes, different cars can react differently in turns than others, depending on drivetrain (front/rear/all wheel drive), suspension, weight, weight distribution, torque, etc etc etc, and all that can/will have a bearing on what is that car's best line.

For example, a heavy car with soft suspension but infinite torque can stop, point, and squirt thru Turn 5 (Mosport) faster than fighting its hideous understeer with a "carry momentum" approach, because you can get back to the gas sooner and quickly make up the time that was lost. Comparing that with something light and nimble, yet lacking the big powerplant (such as a Lotus Elise, for example), can skate thru Turn 5 much faster using a momentum approach.

All that said, my opinion is that most of the fastest "line" definition will be based less on the vehicle, and more on the (often flawed) carbon unit that is feeding the inputs into the car. And each of those carbon units tends to be different from other carbon units, so just in that you will find different "best lines" for different vehicle/carbon unit pairings. Enjoy the melee! :-)

The std line is to make the turn somewhat tighter in the beginning and open up at the end which is a late apex compared to the perfect constant G orbital path around the corner. The idea is to enter a little more slowly and exit more quickly under power. It follows then that if you have a lot more power you should push the apex later (more turn at the beginning, longer runway for acceleration). If you have no power at all (spec miata), you follow the perfect constant G orbital path and conserve momentum/speed. This is an earlier apex.

FWIW, if you have constant Gs to spend, the inside line gets you through the corner in the least time, but doesn't give you the max exit speed. Think orbital mechanics. The sattelites at a higher altitude are going faster but take longer to get around the planet.

No comment on the V shaped lines lots of porches seem to use. I used to do these in my m coupe sometimes and it was certainly fun.

And then there are the NASCAR drivers that like to turn an oval into a diamond. :-)

Hi Peter

For racing, as you know, there's no line. You just go wherever it is possible to put your nose. Freshmen out of years of driving schools usually don't do well in racing, at least initially. They were told by very average instructors to keep on doing ONE line, and get lost when they don't do the SCHOOL line. The good HPDE instructors would tell them all the facets of a corner, and try them all. On line. Off line. Early, late apex. The aim being to be comfortable, yet relatively fast in any situation.

The famous racing line actually doesn't even exist... It's a chimera. He, he.

There may not be a racing line, but there is for sure a qualifying line. In a race, if you can get a little space, the qualifying line keeps all those slower guys off your back. If you spend too much time dicing around on the qualifying line even I catch up and if you screw up, I'm there. If our cars are similar, it could take you a long long time to pass me even if I'm nowhere near as fast as you are.

I look at it this way. Imagine you had a car with infinite power. What would be the fastest line? It would probably look like a straight line, stop, turn and a straight line out. Now imagine you had a car with almost no power? In that case you wouldn't want to have to accelerate, so you need a large radius curve in order to maintain momentum. Real cars are somewhere inbetween, by varying degrees. Imagine the different extremes when applied to different aspects of the car. Thus, different cars, different lines.

This reminds me of another religious argument that frequently occurs - should you always use the entire track? The way I look at that is to imagine that there was an infinite amount of asphalt on the outside of the track. How wide would you go on entry/exit? Obviously you wouldn't go 100's of feet wide on entry, so how far would you go? Thus, there is nothing magical about the edge of the pavement.

Summary: Go where your car needs you to go.

I would like to try the car with infinite lightness so I could just drive the shortest distance around the inside of the track.