New video by Paradigm Shift Racing - The 4 elements of a perfect corner
 

https://youtu.be/N8qBdOs0s1E

<iframe width="560" height="315" src="https://www.youtube.com/embed/N8qBdOs0s1E?ecver=1" frameborder="0" allowfullscreen></iframe>

The presenter, Adam Brouillard, is the author of the "Perfect Corner I & II" and "Perfect Control" books:

https://www.amazon.com/Paradigm-Shift-Driver-Development/e/B017MREQQM/ref=sr_ntt_srch_lnk_1?qid=1488142010&sr=1-1&tag=viglink20410-20

I haven't watched the video (saving it for lunch today) but I have the 3 books and I really like them and they have been helpful to me. But from a quick scan it looks like this video may cover a lot of the points from the "Prefect Corner" books.

Adam presents a physics based approach to optimizing corners utilizing a Euler Spiral, which is a constantly decreasing radius leading up to apex, followed by an expanding radius leading to track out. You configure your corner entry to spiral down to the apex (either trail braking or scrubbing speed with turning, and decreasing the radius as you travel down to the apex) followed by full throttle at the apex accompanied by an increasing radius exit as you drive the limits of the car (for me it is understeer at corner exit under WOT). There are other considerations but that is the short version - summarized by me and so possibly not accurate :)

He gives an analogy in the books of an astronaut that needs to navigate to different places in space using a fire extinguisher for thrust and shows the ideal line and force vectors, and then how to use the brakes, steering, and gas to apply these forces to the car.

The material can make your head hurt, I have read them 2-3 times and parts of it still make my head hurt :)

I have been using this approach the last few events and I really like it. It also feels very safe to me - I can tell right away if I am doing something wrong and it gives me plenty of time to make adjustments.

I will watch the video at lunch and post some more thoughts, but wanted to share in case anybody had 30 minutes to spare this morning :)

Steve

Thanks for the link, I will also save for the lunch hour.

Just watched it. Excellent.

Thanks for posting it!

Good video! I'll have to buy the books so I can get all of the details.

I finally got time to watch this video. I really enjoyed it. It is interesting the 4 points that he lists at the end, in decreasing order of importance:

1. Find the limit
2. Use the Whole Track
3. Maximum Acceleration
4. The Corner Entry Spiral

#1 Find the limit - this matches a lot of other advice from folks like Ross Bentley, such as (paraphrasing) "Drive the car, not the track" and "A driver at the limit but not on the "perfect" line will be faster than a driver on a perfect line but not at the limit.

#1 is a tough one, for me anyway, as I don't have the lightning reflexes and car control to be able to always get myself out of trouble if I go over the limit, and so therefore I am afraid :) With my current setup (still trending toward understeer but not as much as the default setup from the factory since I am running a wider front tire and more negative camber) I have been gradually nosing up to the limit in some turns, which has yielded a great reward in lap time reduction. Typically it is in the slower corners (again because I have less fear there) but I have been gradually increasing in the faster corners as well.

The other 3, to me, all kind of fall into the category of "the line" - use the whole track, maximum acceleration (per the video, design the apex so you can go full throttle there, exception for cars that can spin the wheels very easily), and the entry spiral.

Again paraphrasing, Ross Bentley and others say that if you drive the car on the limit, it will tell you where it wants to go and the line kind of sorts itself out.

Combining that idea with keeping the force vectors in mind with the goal of pushing the car in the right direction using brakes, steering, and throttle, to me helps understand the rest.

I must admit, after seeing the picture at the beginning, I kept wanting for him to say "I must defeat you Ricky Bobby".

This is normal and expected. One thing that I found useful to get past this point was to spend a lot of time karting.

My theory was that I needed to calibrate my eyes, brain, and butt to be able to find the limit and then successfully manage to stay there without losing control.

Karting provides an excellent laboratory for driving at the limit with very little consequence when it is exceeded. This let me train and calibrate my eye/brain/butt system to feel the limit and correct as needed to stay at the limit. Eventually, it becomes second nature/instinctual and happens from muscle memory without any thought.

the guy who sells all the tires at our local track comes from the kart world and is a quick driver. he can put down some serious times in his HONDA FIT with slicks (uses it to haul tires to the track rats).

anyway, i got him to drive my car while i sat in the pssgr seat. like you, i used to try and find the limit by slowly going faster and faster until i would suddenly hit the limit - oversteer - in a corner. it would come as a surprise and i wouldn't be expecting it, my response would be delayed (and unpracticed) and typically end in something gruesome followed by hesitant laps for the rest of the session.

what i learned from sitting with him - driving the car for the first time - is that he would actively seek to find and exceed the limit - he was in a continuous state of oversteer correction. i realised that if you drive like that - consciously crossing the 'line' instead of tentatively creeping up to it and not knowing quite where it is - then the oversteer is not a surprise - you are expecting it/seeking it - and you respond to it more positively and get more practice and comfort with it at speed.

A pro driver/coach drove my car this Monday, and holy #$%&% is all I can say. He's talking to me, taking it easy since it isn't his car, and was 5 seconds faster than my best. It was similar to your experience but my car trends to understeer so he was working that the whole time with some oversteer correction too. I'll make a new thread soon.

Karting, I need to check it out!

drinking and typing, here we go - you gotta dial out that understeer. what are your front rear sway bars/setting, camber, and tire widths?

LOVED IT, and all seems pretty realistic and all, but... was it just me a or, is it still a bit hard to take too seriously that all of the concepts discussed throughout the entire video were only demonstrated or "proven" by the mere repeated playing of a video game?

There was NO part in the video where any of the simulation-based findings were actually proven by the driving of a real car through a real corner.

Yes, he said "often people who drive for WEEKS in a simulator apply the findings in real life and find their performance is better", but that statement was totally just floated out there, and far from being proven. If someone spent weeks in real driving time, would their actual performance not be even better than weeks in a simulator?

Certainly, seat time in a simulator would be much cheaper than real seat time in a real racing scenario.

Despite the heavy reliance on "simulator-proven" theories, I do still have a strong feeling these all may be true/well-founded, so they still do make for some very interesting food for thought. (I just have a bit of a tough time getting past that there was no *real* driving throughout the entire video!)

Is this what the world of racing is coming to? (No need to race "real" cars anymore. Just fired up the central processing unit and simulated race-car user input devices; it's the same!)

He made similar statements as well and said the understeer was limiting the car. Maybe for him :)

-2.0 front, 0 toe, 225/45/17
-1.6 back, .08 degree toe in per side, 255/40/17

M030 suspension with m030 "S" bars

I may try and go some more negative front and back, he suggested to go to -3 in front but I'm not sure I can get there.

i think that is the soln given your sways are not adjustable. you said your understeer is happening at turn-out? if you are getting it at turn-in then perhaps consider a more aggressive rear brake pad (ie pagid yellow front and black rear).

Jakeru - I hear you. Maybe it is a $$$ thing, much cheaper to do the video vs renting a track, although it seems like you could put an aim solo in your car at an hpde and run a session, trying different approaches, and then use that in conjunction with the sim footage.

The author should do a chump race, and then narrate one of his sessions with guidance on what he is doing, especially optimizing corners on the fly based on traffic. I would watch that :)

I just saw this quote from the video author on rennlist, it is a short checklist on optimizing a corner. It matches guidance given by others, but seems to be easy to follow (but hard to get just right :) )

"Not worrying about your line initially, first make sure you are able to reach full throttle at the apex and are at the limit through the whole exit. Then make sure you are at the limit during the whole entry. If you get that far see if your steering is constantly tightening from entrance to apex. To get beyond that point you really need to start paying attention to the whole overall track movement and force direction stuff I'm always going on about."

The thread:
ASK THE COACH - Page 186 - Rennlist Discussion Forums

Kinda, sorta, yes.

Let me explain the thinking behind this - I mentioned karting for the primary reason that it is a relatively easy way to get a lot of seat time while driving at the limit and minimizing the risk. I can slide the car thru almost every turn while learning to countersteer and handle all sorts of driving situations to my hearts content and the worst that will happen is I spin off into the paved runoff area. No harm, no foul. Fire it up and lets do it again. And again. And again. Until I get it right.

The second reason is to minimize cost. Some would say that there is no reason to burn up $1000 in tires if you can do the same for $300 of kart time.

And the same applies to sim driving. Why spend $300 in kart time if you can do the same for $20 of electricity? (yes, I know that I am ignoring the upfront investment, but let's keep this simple for now)

The BIG question is: How well does sim racing or karting translate to the actual track driving experience?

I think that the general answer is that while karting or sim racing can't replicate the car driving experience to 100%, it can be a cost effective substitute for some portion of it.

For example, a day at race track runs me $150 and lets assume that I'll use up 25% of a $1000 set of tires per track day. That's $150 + $250 = $400. Or I could spend the day karting at a cost of $135. The cost difference is 1/3. The question is whether I'll get 33% or more of the benefit from karting as compared to driving my car? I'd have to say the answer (in my experience) is yes. I think that about 50% of the kart time is relevant and transfers to the car at 1/3 of the cost. So in this example and for me in particular, the kart is more efficient at building the skill of driving at the limit. I can do it more because it costs less (and I can minimize risk at the same time).

But this is only a single skill (driving at the limit) and there are many more skills needed to competently race a car, so this method needs to be applied over the full set of racing skills.

When I did this, I found that while karting is a strong contributor to the development of some of my key racing skills (and can contribute at a lower risk and cost), it could never be a complete replacement. I still need a certain amount of seat time/practice on a real track and in a real car to learn to apply the lessons learned in the kart and to build/maintain those skills which are car specific.

Though I haven't done this yet, I imagine that the same analysis can be applied to sim racing. Some percentage of sim racing can replace real driving (whether it is kart or car) at a lower cost, but it probably can't fully replace either.

This approach is now pretty standard for most of the top IMSA drivers like Jordan Taylor who uses sim racing and karting as a way to gain or maintain his skills when he can't physically be in his race car.

I was just in the garage and noticed I corded my left rear outer edge of the nitto. It was hard to see at the track because it picked up so much dirt in the paddock the whole tire was covered. It cleaned off on the way back on the trailer due to rain. Good thing I switched back to my R-S3 when I did (switched back before the last 2 sessions so I could leave as soon as it was over) funny thing, I could feel.the limit better on the "lesser" tire and ran my fastest laps including a new pb of 1:28.38 (9/10 faster than my previous best)

https://m.youtube.com/watch?v=BcIamsS3jFs

In this lap I am (attempting) using the "double apex" rule from those books: Essentially (paraphrasing) drive the limit between the 2 apices on the limit with no speed reversal between them that lets me optimize my entry and exit. This is why I don't track out to the left edge between 1 & 2 and the right edge in 5. As I get faster i think i will get closer to those edges.

I wonder if stiffer adjustable bars would help keep the car from rolling over on the outer edge so much? Someone recently had some gt3 front bar and tarret rear bar for sale, maybe I should have got it.

My tire wear on the r-s3 is pretty even across the tread but the nt-01 is definitely wearing more on the edges all the way around.

This set of nt-01 is done even though there is tons of tread left on all 4 (with the exception of the 1 corded edge).

Maybe I'll stick to the RS3 for a while as i get comfortable on the limit. I know i said that once before when i sold my R888 :) i am not enjoying the fact that i corded that tire and i enjoy catching people on "lesser" tires :)

Tom you have me desperate to try some karting. :cheers:

There is one in Jacksonville, about an hour away...

The comments about karting remind me of when I first started driving. I was adamant in learning the handling of my VW Beetle and learned to sense where the CG of the car was, what forces were acting on it, and where the edge of my grip was. I want to be that way with my Boxsters, but its not so easy anymore. Back then as a teenager in a rural area when the cops saw me doing donuts in a parking lot, they would just smile and shake their head. Not so much anymore. I really need to find a large open area where I can just play with my car without worry.

Steve, I recommend that you stick to your current set-up until you stop improving your lap times. Until you are at the car's limit (not YOUR limit), all you will be doing is wasting a lot of time and money.

i've seen people suggest that before and struggle with it. it's like telling a lumberjack not to buy a chainsaw until he gets as good as he can with an axe. if you are out to cut down as many trees as possible then get the right tool for the job.