ProCoach

Not so at some of the larger Eastern and Midwestern tracks…

ProCoach

Great post, @ydd! Love JK!

It’s wonderful this fruitful discussion and exchange of ideas takes place and thank you for promoting a variety of valuable material on your podcasts and other offerings.

The idea of the apex area being the slowest point is a good one, and not necessarily one and the same as the clipping point. That’s one of the reasons why I prefer a definition of the apex which includes area.

I think many people paint a broad brush with the word overslowing. My interest is to find out where this is happening, how much and what to do about it.

It’s actually quite complex and dynamic. It moves in area and in volume of the drop in velocity under the ideal. And since basically velocity through a given radius (even a tiny portion of one) equals calculated g loadings, this is possible to do with careful study for MANY segments of that radius. Keep breaking it down to narrow down where, what and why this over slowing is happening. Then, devise a plan to incrementally fix it.

While conditions change, and while there is an aero component, it’s still the same at that moment, traveling through the desired trajectory at that corner. You just have to find it and reduce it incrementally through a very detailed plan.

mglobe

Yeah, I've driven an SR3, and it's not a slow car at all. I only got a handful of laps in it, but the things you can do with that car are amazing.

ProCoach

A purpose-built tool. A scalpel to the standard street car meat cleaver! Once you drive one, hard to go back!

Manifold

Guys with a lot of power and crappy tires remind people how crappy their tires are and don't mention their power.

Guys with lower power in light cars with grippy tires and aero remind people how little power they have and don't mention how light and grippy their cars are.

In the end, the lap time tells us what the cars can do.

Regarding top speed, my GT3 is rated for over 190 mph, but no track I've been to enables it to get to more than about 160 mph. I wouldn't want to be doing over 190 mph in a street car anyway, and I have no unmet desire to find out what that speed feels like.

ydd

Thanks Peter.

i've a question for you on this stuff. Assuming two perfectly executed drives through the same high speed corner, would you expect an earlier or later apex (area) to be faster?
Just wondering in this discussion whether any further contextual information is important or whether we have enough just by knowing it is a high speed corner in a car with some aero load... ?

My personal understanding is that an earlier apex (area), typically prior to the clipping point (to carry on the theme!) is going to be faster.
What do you think?

As an aside, nearly every F1 / pro engineer I've had on the podcast have all prioritised the slow corners as the ones where there is most lap time to be gained - simply because you spend more time in slow corners as a proportion of a lap.
This of course assumes the driver is near maximising all the grip in the faster corners - which in my experience coaching non-pro drivers, is not always the case i.e. high speed corners are scary!

If anyone is interested in the maths as to why the slow speed corners are worth your attention, below you can hopefully see a screen shot.



Comparing the speed difference needed to gain the same lap time improvement in both high speed and low speed corners

The image is trying to show you the difference in speed you need to gain 0.01 second in lap time over 1 metre, in both a slow and high speed corner / part of the track.

I appreciated this is quite a lot of lap time gain over a short distance - whatever units of measure you prefer for speed and distance - but it is just to illustrate the point really.

What I take away from this is that the gain in lap time between taking a corner faster in a high speed corner is not as much as I thought it would be. Equally, there are whole chunks of time to be found in the slow corners with relatively little extra speed.

Sorry if this appears a bit off topic but my hope is simply to share my experiences in the context of "at what point should you accept your high speed corners are probably good enough and then double down on finding time in the slow stuff."

ProCoach

@ydd Your excellent illustration is EXACTLY why I’ve stressed the outsized importance of navigating the slow corners well, because your math shows it exactly and correctly, jibing with my 18TB of collected data from all levels of drivers, but particularly top-level drivers including Daytona, Sebring and LeMans winners, along with a WDC and some current F1 driver data.

When you say: “Sorry if this appears a bit off topic but my hope is simply to share my experiences in the context of "at what point should you accept your high speed corners are probably good enough and then double down on finding time in the slow stuff,” This is NOT off-topic and completely germane to the conversation and the subject, which is the challenge of going faster.

I also believe people massively overstate the benefits of aero, based on not only their own limited GT experience going to a car that does in fact have usable and significant aero, but also the inability to conceive of, therefore execute, the increase in speed possible in the fastest corners. The idea of slow speed corner aero gain is really not on, so the goal is the same, aero car (formula or sports racing) or not (GT with some more planes bolted on).

I got into this debate many years ago with Ross Bentley and I think we’ve both helped each other to understand, but the reliance on eaking out the last mph (or couple), when proportionately or as a percentage, is NOT making a big difference, especially when it adds significant risk, is silly and the result of conversations at the bar or pub after the day between drivers, not factual information. He placed an inordinate importance on places like the Kink at RA, the Uphill Essex at VIR and other places, while I was all about T3, T5, T8, T12 and T14 at RA and T1, T4a, T12 and T14 at VIR. You’re just in the slow stuff SO much longer that a small difference makes a difference.

Thank you again for this stimulating conversation!

roadie13

Fixed that for ya

ProCoach

Yep, words matter. Thank you.

ProCoach

I'll just add that this is the NUMBER ONE challenge for most drivers I work with.

A natural corollary to this is "is a long lift better than a short brake?"

I propose generally not, simply because the higher percentage of the lap that the tires are used close to maximum demonstrated grip, the quicker people generally go.

Can't do that when "long lifting," and long lifting tends to be a premature coast...

txbdan

There is a Racer360 video talking about breaking a turn into two parts, entrance up to the apex and apex out. In this he talks about braking to the apex and throttling from apex out. It sounds simple, but its prob been the biggest lightbulb moment in my driving career. When entering a turn now, I visual the braking zone not as the straight before a turn, but as the track all the way to the apex. This extra distance lets my brain allow me to brake later and lesser and trail brake all the way to apex. This gets the car nicely pointed so im setup to throttle-at-apex as the top priority. Since this lightbulb moment a couple years ago I've won two time trial class champs and one overall club championship. It's wild.

Montaver

Lots of interesting discussion here, so I have a question. Lets take turn 6 at WGI, my standard is to brake in a straight line slightly mid to right of the track, before turning in towards the Apex which requires a small period of maintenance throttle before you can go flat. You can trail brake to the apex but it doesn't really feel necessary, because you are heavily already loaded the front because of the hill. Based on what I'm reading here there are few if ever instances where you really want to be on maintenance throttle. Should I brake in deeper, turn more aggressively and go WOT straight away? I've tried it this way and it takes much more effort to manage the weight transfer and from the data isn't actually faster but maybe I am missing something.

Manifold

That's a crazy corner, always a pucker factor for me.

Of course, first priority in that corner is not to spin or hit the wall at the exit.

It's a complicated corner because of the steep downhill, lots of camber, and lack of visibility of the exit. I haven't looked at data, but I'd guess that coasting may still result in some acceleration because of the hill, so some zone of coasting may make sense in some cars, and trailing of the brakes needs to account for the increase in camber in the corner entry.

Back when I had less fear, I recall noticeably drifting in that corner (not sideways, just big slip angles).

Interested in what others say about this corner.

txbdan

I just looked at my video from a couple TTs at WGI and I do not brake all the way to apex in T6. I think I trail brake until I kind of find the camber groove and then the groove sort of takes it from there to apex. I also get on the gas a little and then let off so im probably over slowing *ducks*. I'm prob just afraid of the blue bushes. I'm not sure I always literally brake to apex, but in trying to it puts you in a different mindset. Occasionally I do, though, because switching my foot quickly from brake to gas at the apex is something I've thought about trying to smoothen. The bowl at NHMS comes to mind.

ProCoach

Yep, super tough corner. One of my favorites!

I bolded the above because if it doesn't feel necessary, you've overslowed...

Have you walked the track there? The camber gain is enormous, and the grip improves from apex area on out.

It's also MUCH longer than ninety degrees, too. Almost 140 degrees.




If you reach the inside curb before you can see the worker station straight on, you're early or turning in too quickly. Generally, you should slow to that point.

Most of the people I'm working with driving very quick cars are trailing the brake well past turn-in and actually developing some slip angle as they get within a car width before being against the apex for a few car lengths.

They do that by controlling the speed of release of the brake at that point and then picking up throttle when it becomes clear that they'll make it to the inside, at the right place. But that point is a long way in, more than ninety to a hundred degrees of turning.

In the car, done right, you don't have a sense of how much declination (drop down) and camber gain there are, but when you look at tire loading and g's, it's one of the most taxing corners on the track, done right...