Visualize the outcome

I'll have to think about the rest of your post later, but I just want to say finishing 6-8s behind in a race is pretty durn good. That's not considered "6 seconds off the pace". Only your lap time difference is how far off the pace you are. Sounds like you are actually only 1s off the pace? If so, that's outstanding!

 

Well to me the answers are complex and dependant on many variables. You could answer in many ways including controling your entry to maximize middle and exit corner speeds and looking through your corner as opposed to looking "at" your corner more in line with "visualizing your outcome" idea. My first thought however is that you need to decide if your post is about racecraft or timetrialing. The two are very different and the answers are different for different games. Your early sentence talks about racecraft which to me is not about going fast but beating the other guy. You end with a question which really talks about finding the ideal timetrial line and maximizing your momentum through it. These are really separate issues in my mind. In my own case I am decent racer but lousy timetrialer. Some would say how can you win if you can't drive fast? Well racing is about driving fast enough not driving that fastest golden lap.

 

fatbillybob, i have to respectfully disagree. yes, racecraft is so important, but driving the fast line, well, as fast as possible, is also a critical skill to finish well among equal cars, you must also qualify well. also, even during a race, if you are 1s off the pace yet in the lead, you are giving your competition many opportunities to keep up and be there when you make a mistake. if you are faster than the pack by 1s, you quickly build yourself a cushion for mistakes. so i think you need both skills and you are under-emphasizing the importance of being able to turn a fast lap.

as far as the "two" keys to fast corner speeds, well the way the question is phrased it does seem to be asking about min corner speed and not overall corner speed. i would say that first and foremost, the first key to going fast is most time spent at full throttle. so to maximize this through a corner, you need to select a line that allows that -- which is the slow in, fast out line. 2nd, brake less.

this is obviously wrong. the longest line through a corner is around the widest radius. clearly that is not fast. i'm sure you meant something else. (also, the fastest line through a single corner may not be the BEST line through that corner; you have to consider what's next.)

 

Yes I agree with your statement but...it is really a "balance" that makes good racecraft. That's why I called it "fast enough". Many a fast driver has wasted their car building a gap only to be passed by a smarter guy who saved his car and himself in the finishing laps of the race. IMO the import part of the race is the start and the finish. The middle laps are there for you to set-up to be there at the finish.

 

and how do you set yourself up for the end? by running fast laps during the middle. if you get yourself a cushion you can then back off a little. if you are 1s off the pace and always fending off the guy behind you, you are wearing yourself out. once you do get passed, forget getting by again (if you are 1s off).

 

That's it.

Exactly. You have to resolve to drive 100% every turn, every lap, every session.

You neglect to tell people that you were more than twice your finishing gap off the pace starting out. The rate of improvement was pretty significant just on Friday, but in reality, YOU are the one that pushes the pedal. YOU have to take responsibility for your performance. That's what's great about racing!

With your permission, I'll post your velocity versus distance graphs in this thread comparing your performance on Friday to a reference lap and you will see that your evaluation of your T5-on to T10 and T12 "exhale" is on the mark. Part of what we worked on was getting you more familiar with the track so that you could have a plan, instead of falling steadily behind by not being able to KNOW what was ahead.

I think you're being hard on yourself. You're thinking a little too much. You have good analytical skills, you've done the research out of Carl's book, but now you have to push the boundaries a little...

 

That could probably use some fine tuning, but I think it does capture the idea pretty well -- for a flat corner in a neutral car.

But for example, there's a turn at MMP where (in my understeering car) you have to overdrive the first half of the turn, lift at the apex to point in, and then power again for the 2nd half. Definitely not the straightest arc. Classic double apex I guess. But the similar turn on other tracks, but where there might be a little banking or other characteristic, is a single apex.

Also, different cars with different levels of power and different tire grip have different ideas of what constitutes a "straight line". So some cars can tolerate a tighter radius on the exit and still pull away at full acceleration, hence their fast line will be tighter than a less capable car's.

I'm not picking on you here, but I've seen others use the term "fast-in/fast-out" and unlike yourself, where I have seen it before the person is talking as if they are god's gift to racing and in any case certainly better than their instructors who are teaching them slow-in/fast-out. So I'm going to take the opportunity to present my thoughts on that.

There is no such thing as fast-in/fast-out. Slow-in does not mean absolutely slow, it means relatively slow -- you are taking a line such that you are giving up entry speed to gain exit speed. e.g. by driving the outside radius with geometric apex, you have a certain entry speed -- I think the maximum possible actually. But by starting from the outside, on a line whereby the exit is as straight as possible, you are necessarily giving up entry speed relative to the maximum possible entry speed, because your turn-in radius is necessarily tighter than it would be otherwise.

So the "slow" part of slow-in just means slower than the maximum possible had you been on a line with wider initial radius. It doesn't mean slower than the car can actually go when you are on the fast line. You still drive fast enough to utilize all available grip. The Skip Barber book talks a lot about the geometry of all this and is fantastic IMHO.

When someone is slow on entry, that's not slow-in, that's just plain slow. When someone is fast on the exit, they necessarily were slow-in.

Just my 0.02. I'm certainly no expert.

 

mousecather...I starter another thread to not hijack this one regarding your last comments. Would you go there please, title: "throttle steer/lift oversteer"

 

That's unfortunate. Racing, or even track days, is such good therapy. Too bad it is so expensive.

 

I love that turn!

 

In Alan Johnson's book he states "don't listen to what you hear about cornering, road races are won and lost on the straights" (my paraphrasing)...

Of course, he is right, that maximizing speed out of the corner (via an expanding radius) gets you down the stratights faster and makes for a fast lap. Most everybody tries to do that and, assuming that you are were you are supposed to be, there won't be a huge difference between you and the others in similar cars.

If you look at the track geometry from above, you easily see the concept of an expanding radius and the idea of getting down the straight. What lots of folks don't see is that it applies on the entry too, where if you trail brake you can get down to the apex in less time than if you slow down too much on corner entry and spend a lot more time at max lateral g. While a trail braking entry is harder to do than braking more in a srtaight line, you cover more distance at a higher speed (the early part of the corner were you still aren't at maximum lateral acceleration and still braking), and that is where the time is often gained. One reason that it is elusive is that it happens pretty fast, and it is difficult to realize the potential gains.

There are places however, like on a 180 degree corner where you might want to trail brake in and then hug the inside for a bit and then expand the radius out to maximize exit speed. If you watch the NASCAR guys race on the road course at Sears Point, you will see the experienced road racers picking off the NASCAR guys by doing that at turn 11.

What happens here is that the guys going the long way may, (and I say may) get a bit more speed down the straight, but they loose a lot of time in the turn waiting to get on the gas and therefore that makes for a longer lap time.