At FATT this past Friday, the noobs (myself included) were being instructed on the proper line through a corner. It was for the most part a general discussion, as we aren't capable of understanding real detailed analyzations about the specific course (Summit Point). I understand that late breaking and taking a late apex are the best way around a corner, for the most part. I think the problem I'm having is that I have it in my head in a series of separate motions. Turn-in, connect to the apex, connect from the apex to the exit. What I think I SHOULD be doing is looking ahead and making all of that one line/motion.
Anyway, and Bryan, at Beaverun you were helping me understand this better, so maybe I just need more practice with it, how do I judge exactly where that late apex is with respect to the turn-in point? I'll have to read this again tomorrow and see if I'm making any sense, because it is 2:30 in the morning, and I've had a long week.

 

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Yes it should all be one smooth fluid motion. As your learning progresses you will incorporate trail braking as well. T5 at summit is a great place to practice trail braking into the turn - its almost neccessary to get a front heavy car to rotate there, that and the fact that you have not very much room to reduce your speed quite a bit, and you will find yourself trail braking in without intending it.

If you look at a corner, a late apex is the point at which you apex the turn *past* the geometric apex of the corner. This will usually promote higher exit speeds.

 

yea, but you brake down to 45mph when your actually doing the turn in and trail braking.. Even though your approach is hi speed, the corner isn't..

About late Apexing, I only do it for compound corners, like T7-T8 to setup for T9 at summit.. If you take a normal apex line through there, you just can't plain take T9 nearly as fast.. But, T10 is "normal" apex.. There is not a corner that matters after the exit, until you get to T1.. If you late apex 10 w/ a low HP car like hondas, your going to be slow down the straight.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">Can you recommend a slower corner to practice on?</TD></TR></TABLE>

CMP Turns 1, 5, 8, 11, 12, 13, 14

 

I'm with Corey. I don't apex late on single turn sections of the track. Our cars handle very well, and if I take a normal apex, it lets me use all of the track at full throttle. If I go late, at say T10 @ Summit, then I'm just pretending to track out, as opposed to being forced to track out all the way over the rumble strips.

It would be marginally different if we were driving cars with 300hp, but we're not. Oh how I miss those days

Regarding Summit in the wet. It is extremely slippery. Even still. You should have driven it 3-4 years ago before the repaved it. The nickname Slippery Point was very appropriate. It was like ice. Unfrigginbelievable. Stay on the concrete patches in the wet. They drain better @ Summit. This is not true for all courses in the wet. You just have to drive them and figure them out.

Warren

 

This is very helpful, thanks for the help everyone. Thinking back, I did take a late apex through T10 a few times and definitely did not need to track out to the rumble strips. I'll be back there in June, so I'll keep all of this in mind. Just as a general question, and I'll just use SP as an example, for a corner where there are the curbs or whatever (red/white striped, taller than rumble strips), are the normal apexes usually in the center of the curb? For T3 and T4, as well as (when I did it right) T10, it seemed like this was the case.

 

Be careful in T10. Its much less forgiving this year.

 

The geometric apex of any given corner is a little bit of an abstraction. I tend to think of all apexes as relative - earlier or later than one-another. Ideally, you want your apex to be as early as possible while still allowing even or unwinding steering AND full throttle from the apex clipping point to the exit clipping point (or CP, where you get to the edge of the track).

Best practice is to work backward, starting with considerations at the exit of a given corner. If it is onto a straight (rather than into another turn) you want to run out of road right at the exit CP. If you do need to be set up to optimize another corner, you may compromise by not using all of the road coming out of T1, to realize a net reduction in lap time in T2. Once you know where you want to be at the end of the turn, determine where you need to put your apex CP in order to make that happen. Start TOO LATE and move the apex gradually earlier until you are binding the car up with additional steering input or anything less than good throttle from the apex to the exit CP - then go back to a smige later apex for general use.

At this point, you have to determine where your turn-in must happen, to assure that you get to the selected apex without drama. This in turn then defines where you need to be getting off of the brakes, whether trailbraking or not...

All of this can be done in pretty much any corner, if you remember that you can approach any given turn at a reasonable apex speed, rather than having to jump all over the brakes to slow to that point: If Summit T5 can be tackled without drama at 40mph, you can go 40mph on entry rather than 95. I am assuming that we are using an HPDE kind of environment to learn how to drive, rather than keeping track of lap times...

Add threshold braking and correct downshifting technique to the mix and you are ready to learn about racing.

Kirk

PS - I am a HUGE fan of putting a couple of painted apex marks on each corner for learning situations. They do NOT have to be the "right" apex (since they never will be for all cars) but instead serve as reference points - "Try hitting about 5 feet this side of the blue dot..." If a driver can't consistently hit a painted mark, he/she is going to have a horrible time finding a repeatable apex on a track with moving cones, grass, and broken concrete at the apexes.

 

Wow, thanks Knestis, that's incredibly helpful. I hadn't thought about thinking backwards, exit first, what to do to get to exit, etc. quite like that. I'll have to give that a shot when I go back. Curious, would the same idea apply to an autox course, or is that too short?
I understand what you mean about if a turn can be entered at 40mph, just come up to it at 40mph, but then the braking isn't the same. For myself at least, I find when I'm forced into a learning situation (such as "holy crap, i better slow the hell down or I'm going facefirst into that wall"), I learn what needs to be learned much quicker.
I also like the idea of painted apex markers, though I don't think the SP officials would like us running out there with spray paint or something...

 

Plenty of track groups mark apexes and even exit points with cones off to the side of the berms. It works wonderfully.

I received a lesson once that went something like this: You're almost always safer apexing later rather than earlier. The worst that will happen is you'll realize you could have apexed a bit earlier and still gone fast without binding up the car. So on subsequent laps you can apex earlier until you find the sweet spot. However, if you go in far too early and run out of track on exit, well, you lose. Play it safe. Apex late first time around.

-Adam

 

Having done a bunch of different kinds of racing, I am comfortable saying that autocrossing is the hardest - simply because everything is so condensed. The time that elapses between turn in and exit clipping point on a road course (or even a rally or hillclimb) is WAY greater than in an autocross. The distances involved are equally small, making the need for precision that much greater as well. I am sure that really good autocrossers actually pick a line but it has always been just a sea of cones to me so I'm not the guy to ask...

Kirk

 

Don't forget that quite often, "The Line" in say turn three, is often dictated by what's ahead of you. Turn four? A big long straight? A short straight followed by an opposite-direction turn four?

Keeping your vision WAY up will take care of a lot of this for you with time and practice.

 

We had cones, but from people running off, and later I think from the instructors removing them, they were gone or moved, so that didn't help towards the end of the day. I agree about setting up the line not only to get through one corner, but also through the next, and the next after that. I guess you really have to look at the whole track in that respect.
I've heard something before, "Good autocrossers always make good roadracers, but good roadracers do not always make good autocrossers." I always figured it was because autoxers are used to reacting really quickly to that next immediate turn, so on a road course, it would almost be more relaxing, like they can take it easy I guess. For that to be the case though, there must be some sort of line in autocrossing. I dunno. My first autox will be this coming weekend, so I'll try to ask someone.

 

That's interesting that you guys are talking about apexing earlier on some corners being faster. I'm a track n00b, and my only experience is with Road Atlanta - so I guess I'll use that as a reference.

I found that in my car(E36 M3, stock), the later and later I could feasibly apex, the faster I could take each corner, or more specifically the faster I'd be on exit of each corner. My instructor seemed to convey this as well. I found I could get on the throttle earlier, planting the rear and allowing me to basically go WOT on almost all higher speed corners. For instance, the later and later I got into T12 at RA, the less drama there was, and the faster I could go while feeling more in control.

I heard this was a pretty "late" corner as far as they go, but are there any corners at RA that I could maybe tackle earlier and be faster? Maybe T5 and really run it out wide over the curbing on corner exit?

Or is this a fundamental difference between RWD and FWD? With starting to dip into the throttle at turn-in, then feeding in more as I opened up the steering wheel - I learned to trust the throttle to keep me stable and get me through a corner. From the little "performance driving" I had a chance to do with my Integra - it seemed like I constantly was having to do tricks to get the car to rotate, from abrupt lifting to left foot/trail braking to transfer weight forward and reduce rear grip.

So is the idea of FWD that some corners are better taken at a higher rate of speed and a tad earlier, using the throttle to reduce front grip and make the car push on track out just a manifestation of the inherent differences between FWD/RWD? With RWD do you guys think you would be taking these turns you describe as "normal" apex turns later in a RWD car, since being later usually meant getting on the throttle sooner and harder?

Sorry for the barrage of questions - I'm just trying to digest some of the things I'm reading and apply them to my limited experience, or just even see if what I"m reading is applicable to my past experience.

 

I think what you describe (going faster by apexing later) is simply a result of your initial turn in being too early, resulting in a too-early apex - and a messier exit. You were tackling the problem the "traditional" way - from the front - which typically results in exactly what you describe. This is pretty much the way everyone learns it.

When I said "earlier apex is faster" I meant starting from the other end. A too-late apex is going to generally feel (and be) safer but will be slower than the potential of the car. This is a great example of why I think "early" and "late" must be thought of as relative. The ideal answer (assuming the same car) would be a later apex in your case - later than you are likely to start with, anyway - and earlier in my case, since I am going to start by focusing on the exit of the corner.

I am hesitant to make generalizations about the differences between front- and rear-drive chassis but suffice to say that they will exist.

Kirk

 

Just in general, as of course each car is different, I thought FWD cars had more of a tendency to understeer, and RWD cars had more of a tendency to oversteer. The ITR of course is an exception to this, just as some of the newer RWDs are exceptions to that. Knestis, I know at SP the instructor drew a diagram of late turn-in, early turn-in, etc., and showed how each one worked relative to each other, as far as when you can get on the gas and how fast you'd be going entering and exiting the turn. I don't have a scanner, and I didn't draw it at the time, but posting up a pic of this might help with some confusion. My own confusion came when I tried redrawing it a few days later, as the later turn-in kept having a normal apex, and I was just completely thrown off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Be careful in T10. Its much less forgiving this year.</TD></TR></TABLE>

Why is that? What did they change?


Matt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by speedracer33 &raquo;</TD></TR><TR><TD CLASS="quote">Why is that? What did they change?
</TD></TR></TABLE>

Theres no big *** pavement patch to put 4 off on the curbing and in place of it is a nice sand trap. Given the speed of the turn, i think its more dangerous this way, as sideways cars into sand traps are usually bad.

 

That big run off patch was relatively new anyway. Us old-timers are used to the track without it. It makes sense that they got rid of it actually. It was supposed to keep people out of the gravel trap, but all it did was make people change their line and take the turn faster to use all of the run off on their exit. So the cars are going faster, and are closer to the wall than before... clearly not the end result that they wanted. So just back it down about 2mph and you'll be fine.

Matt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Knestis &raquo;</TD></TR><TR><TD CLASS="quote">When I said "earlier apex is faster" I meant starting from the other end. A too-late apex is going to generally feel (and be) safer but will be slower than the potential of the car. This is a great example of why I think "early" and "late" must be thought of as relative. </TD></TR></TABLE>

I saw a quote from a famous racer (whose name escapes me right now) that puts what you wrote in an easy to remember way: "You want to late apex that corner as early as possible"

From a noobs perspective, what you need to work on first is CONSISTANCY. Once you are hitting your marks consistantly (and by that I mean within inches) then you can work on varying your turn-in & apex to find out which line is fastest for YOUR car on THAT track on THAT particular day.

In DEs we stress late apexes because they are safe. If you aim for a late apex and miss it by a couple feet you'll still stay on the pavement. If you aim for a perfect apex and miss it by two feet you will end up in the weeds or worse.

joel

ps. the marks at summit pt. have been repainted so it remains to be seen how good they are. the old ones were pretty good. Tim from BSR painted the new ones and hes a formula car guy so I dont know how well they will work for doorslammers. every time I've been to SP this year its rained so i havent really used them yet

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">Theres no big *** pavement patch to put 4 off on the curbing and in place of it is a nice sand trap. Given the speed of the turn, i think its more dangerous this way, as sideways cars into sand traps are usually bad.</TD></TR></TABLE>

I can't say I used it 2 weeks ago because it was raining but I could have SWORN that patch at track out for T10 was unchanged.