Driving at the limit and slip angle
 

Is it possible to describe using words how one would feel that they are driving at or near the limit? How do you “feel” a slight 5-8 degree slip angle is generated on all 4 wheels?


The way I drive I can feel that if I get on the gas a bit more I am going to get power oversteer, if I turn the wheel in a bit more the car is going to understeer, if I lift mid corner a bit too much back end starts to come around. Which kind of means I am at the limit, my lap times are nowhere near the limit though.

I currently run 2:08 at Buttonwillow on a stock gr86 with half spent 225/17 falken 660s and carbotech xp12s. I think the limit for this set up should be close to 2 minutes since I have seen under 1:58 on cars with coilovers, bbks and 255s.

Street tires should be squealing at 10/10ths, if they’re screaming you’ve gone too far and if they’re dead quiet unless the times back you up, odds are you’re under the limit.

The best word I can think of to driving at the limit is it feels a little “unglued”

Italics: increase your resolution so you can hold slip at will.

Bold: drive more efficiently

The time means nothing without a reference point.

Have you considered getting coaching?

Forgot to add the track, sorry, its at Buttonwillow CW13. Also run 1:30ish at sow ccw.

I worked with some instructors at the track days however it was not super helpful to be honest. Tightened up my lines a bit and showed some corners where late apex is faster. Actually having the coach drive his car and me in the passenger seat was more useful as I felt some forces in the car that made me realize I can push a lot harder and brought down my laptimes 5-6 seconds instantly in my own car.


I would love proper coaching but its super expensive, schools are also multi thousands of dollars for a weekend. I bought Ultimate Speed Secrets book by Ross Bentley and reading through that right now. Have a garmin catalyst and thinking about sending some of my data out to someone who knows what they are doing to give me some pointers.

I want you to think about the bolded a bit more.

Coaching is too expensive, but you bought a catalyst?


Why is lap time of such importance to you? Do you want to "go fast" or "learn how to drive"? While the two are related, time has little to do with driving skill, but fast will come naturally with the skill.


Some things to really think about, because you can always purchase a lap time, but you aren't going to learn to drive well on your own.


I'm willing to bet you'll get more out of one solid coaching session than you will in 5 or even 10 track days on your own with the tools you have now.

My track experience is all FWD aside from some Autocross in a BRZ, but traction circle is traction circle.

I have found at the very limit of grip there is a distinct transition where the tire begins to slide across the surface of the tarmac, and the car almost starts to feel as if is floating a bit. The steering gets lighter, and in that moment you have to be very aware of which way your front tires are facing, as if you lose a little speed and the tire regains grip, it will do so quite abruptly. You’ll often see very fast drivers often making quick steering corrections mid corner - that is an attempt to keep the tire right on that edge of grip and the car pointed in the right direction. In an ideal world, you’re entry speed and steering input would be so perfect that you would effortlessly slide at the tiniest angle around the whole corner without having to make any steering corrections - of course we are only mortal though and staying on that limit is extremely difficult.

I would recommend a half or full day driving clinic, the guys at Fast Sideways operate in your area and seem to have a great reputation. If you don’t want to spend, look for an open Autocross day that will allow you to run lots of runs. For example SpeedSF hosts days at Sonoma where you can do 30,40,50 runs even on the skid pad and get tons of practice. But being comfortable feeling the edge of the traction circle and staying there will be a huge boon to your lap times. I plan on doing so very soon with my new GR86 to reorient myself to RWD.

FWIW, i did about 20 track days in my MK7 GTI, and ran 2:02 Thunderhill East, 1:25 West and 1:44 at Laguna on street tires. I am by no means anything beyond an amateur driver but felt I had pretty good control on the grip limits of that car.

So, I do want to be a better driver. I am sure I’d turn faster laptimes in a GT4, but thats not the point. Buying this RWD, NA semi underpowered light weight manual car was to initiate learning in the first place.
Keeping the car and the track the same with 10-20F variation in temperature, my only ways of measuring if I am getting better or not are faster lap times, or doing the same laptime but smoother, without wringing cars neck, banging through gears, super hard downshifts, and destroying tires/pads.


As far as coaching, I agree 100% with your point. Coaching that I’ve found were , as I said on my original post, either free/cheap and not very useful or super expensive like fly the guy out to the track, pay for hotel and pay for his time kinda of deals. I guess I can try to look for opportunities in between the two. I’ve done 12 ish track days with the catalyst so far, bought for $899, amortization is getting close to transponder rental. Would coaching make me a better driver than garmin telling me to take the next right a bit faster this time around…yeah probably but was looking for a laptimer anyways so went with it

IMO, sell the Catalyst, and get a Solo 2 DL.

I don't think I'd call the GR86 underpowered. If you're not flat almost everywhere, it's definitely not underpowered, right?

Have you considered 86CUP? I offer heavily discounted coaching on 86CUP days.

I have no idea what 86cup is, let me take a look. I am interested.


In the meantime I signed up for alfa club drivers education at sow this weekend. 2 days, 6 hours each, 2+2+2, classroom, track, skidpad. $299 for 2 days, seems like a great deal since a track day pretty much cost close to that.


Why do you think I should sell garmin? Is it that useless? To be honest I have not gotten much from reviewing my own sessions…


Edit: I checked it out and looks great. I guess you are mike from the video on the 86cup site. Can’t do Oct29 but I might make it to Chuckwalla, though never been there. Stock gr86 with falken 660, pads, fluid, top hats and camber bolts seems like 1.5 second handicap and 1 points on the stock class?

IMO, Getting a feel for when the car is in the sweet spot of the slip angle requires:
1) Getting a feel through the steering wheel when the car is just barely responding to steering inputs without understeering
2) Getting a feel through the chassis (via your arse/body) when the rear end is just barely maintaining grip
3) Getting a feel through your internal equilibrium about if your body is experiencing subtile shifts (increase/decrease) in G forces
4) Using your vision to determine if the car is maintaining the intended trajectory through a turn
5) Experience in 1-4

Coaching will definitely help you recognize 1-4, but you'll need seat time to perfect them.

B

Definitely read Speed Secrets by Ross Bentley.

The limit is different for everybody, and it will also differ based on your technique and driving style. The limit is hard to describe, but in a way, you will be on the edge of control. But don't mistake being at your personal limit to be the same as being on the absolute limit.

It's good that you can feel the car at the limit. The next step is to figure out if what you are doing for a specific corner or series of corners actually minimizes your lap time.

The absolute drive combines the best line with proper technique and driving at the limit. More than understanding what to do, you need to understand why. So, if you're trying to aim for the times that 86 class top drivers and record holders have, the best way to learn is compare your driving to theirs. https://www.86cup.us/records/

This can be done via video, with data, or both. If you're not ready to review and analyze data, devices like the Catalyst and Aim won't be very useful. If you're more receptive to lessons or interactions, this is where coaching and and being in the car with others can help. Even racing sims are excellent for this. You get tons of seat time to experiment with zero risk of wrecking when you experiment with racing lines and the limit.

The Garmin can only compare you to you, and doesn't log any chassis data. The AIM can log chassis data.

If all you wanted was a timer, the AIM is already cheaper anyways, and has more timing functionality.

Your car is already street class. Stock class is literally for nearly stock cars, not cars prepared like yours.

You can probably find all this in speed secrets - I haven't read the book but I spoke with Ross recently and have my own expertise here


It's easy to saturate tires, it's hard to drive right at the edge of the traction circle, which is where the peak grip is.


If you're turning your wheel more and more and more and getting no more rotation, it's because you're already past the peak - no matter how far you turn the wheel the tire is gonna generate the same amount of force. Unwind the wheel.


If you're spinning your rears but you don't wanna spin your rears, lift a little.



If you're trail braking but somehow still understeering, lift off the brakes or unwind the wheel. If you're getting a lot of power oversteer, you got back to the gas too fast while the car is still rotating.



This is all improved with seat time.


Eventually you start to understand how to maximize vertical load on the axle you care about - brake or lift to shift weight forward and give front axle more grip potential. hit the gas to shift weight backwards and straighten the car out.


In the below plots, Fy-SA is lateral grip, you can see the peaks increase with load increases (going from blue to red is higher vertical load). Same with drive/brake on the Fx-SR (slip ratio) plot. Bigger peaks = bigger friction circle.
Notice also, that the force drops off after the peak.

https://optimumg.com/wp-content/uplo...8/tire_1-1.jpg


Side note I've heard that the falkens heat cycle out quickly, way before tread is fully worn.

X100

More seat time uncoached can just lead to the solidifying of bad habits. If you can’t afford or set up a coaching session try sending a lap to Dion at Blayze Coaching. Better even if you can send data also. Really helped me at Laguna. Nothing Beats 1 on 1 in the car though.

Reciting theory, and then applying it while under stress are two completely different things. Especially while learning. Having someone in the car observing and talking you through the session and then breaking down your sessions is a total game changer.

The RT’s drop off a bit after the first cycle but don’t last long enough to cycle out.

^^^^this. This is where coaching comes in.

Fully agree, op seemed like he wanted to understand the theory a little better to me. The practical advice is that it sounds like he's asking too much of his tires.

My bad, mistook you for the OP.

You should give your complementary NASA (national auto sport association) membership a shot especially if you're near SoCal. I'm in the great lakes region, and I cannot believe how cheap your NASA events are in SoCal.


https://members.drivenasa.com/events/3734#register-sec


NASA is generally regarded as having a very high quality driver's ed program, focused on getting you into racing of some form, or instructing. If $300 for a weekend of track time +instruction is more expensive than what you're paying now, then DM me where you live so I can move there too lol


If NASA doesn't do it for you, Gridlife, PCA, AudiClub, BMWCCA, and Chin Track Days all offer driver's ed programs open to anyone with any car.

SoCal has uniquely cheap track time. $300/day will get you a track day at Laguna Seca!

If you don't mind low quality seat time, sub-$100 Streets of Willow days are a thing.

And four days at Laguna Seca costs the same as a season pass in Colorado. [emoji2]

Shit now I know I’ve been away from the track too long, my last Laguna track day was $175

I'm new to the RWD platform but I would say the car starts to 'feel light' at the end where you're getting some slip angle. You may be able to visually see the change in direction as well.

I don't know how to explain the "how" but being able to feel the slip angle or limit is based on your sensitivity as a driver. Being able to see/feel the cues would depend on your experience, skill, and talent.

Most track days at Laguna “that I have seen” been about $400 a day.

I have never been there but my buddies who have done it on street bikes swear its the best track ever etc…


What makes Laguna Seca better then a place like buttonwillow. I assume facilities, maybe size of track and layout?


Also I am all for a $100 SoW track day, though its probably gonna have 7+ run groups with 1 hour 45 minute between each session.

In my opinion it's not better. And the four other Rocky Mountain 86CUPers I drove it with agree. Both are fun tracks, but in very different ways.

I think overall Sonoma is the best track in CA. But BW is a close second and way closer for me.

Sent from my Pixel 6 using Tapatalk

Laguna holds a lot of racing history and for many, that is the allure. Personally, I love Laguna. I base my driving progress on how I'm doing there. You HAVE to hit your marks there or the lap is toast. I like all Calif tacks except Streets. Many of the cheap days there bring out some very questionable drivers and cars.

How dare you call me Questionable!!!! :)

not sure what you are trying to accomplish. flogging your car on street tires without coaching isn't going to teach you much. Slip angle on street tires isn't the same as on slicks. However, if that's the stat you are chasing, Bentley has a section on slip angle. 5-15% is ideal. However getting all 4 tires at the perfect angle is unbelievably difficult, bordering on impossible. On race tires with a proper alignment with a suspension that can keep the tires gripping, but s a setup that teams spend lots of money on.

Ross will tell you to work on the corner before the fastest/longest straight. Master that corner, especially your exit speed. Then keep working through each corner before the next shorter straight. Whatever is left is of least importance.

If your data logger doesn't, get one. There's a number of apps that run on a cellphone. If you aren't reviewing your data after every session, you missing an opportunity to learn something. Aim has a collection of videos on how to use their system. You can use their lessons to apply to your data system.

If you don't keep a log of every session, you are missing opportunities to learn more. Ambient temperature and tire pressure are a starting point, as long as you use the same tire gauge every time (harbor freight vs longacre vs $$$$; doesn't matter). Log starting pressure and ending pressure. Adjust pressure to match handling, or use the chalk markers to determine the rollover on each tire. Once your tire pressure results in a consistent wear line, you can start chasing a more consistent lap time.

Coaching is worth every penny, assuming you can learn from the coach. Flying someone in seems overkill. Visit a track day with one of the car clubs. Porsche/Audi/Bmw usually have a couple of instructors who race. Ask for one of them. Expect them to ask you about vision references (a speed secret).

If you can't find a coach, get a gopro to focus on what you are doing behind the wheel. Match your actions with your car data. If your data logger can read obd2 data, determining steering angle tells you if you are over-steering. Also tells you how much throttle you are using and when.

At apex, that's when you start applying the throttle. By track out point, you should be at max throttle if not before. You should be max throttle until the next corner's braking point. Only enough brake to hit the apex at max traction (tire rollover wear mark will maxed here).

Keep in mind, running at this speed, will greatly increase tire & brake wear. You'll likely find your brake fluid needs to be changed more often. Oil changes will become mandatory after every track day. You don't have to do things, though. Invest in a good towing plan.

Super helpful thanks. Haven’t finished reading Speed Secrets yet but so far I like it a lot.

Ross teaches clinics. The Audi club in Seattle hosts a yearly track event that he shows up for. Worth every dollar.

check his virtual track walks - https://speedsecrets.com/virtual-track-walks/

if you have never done a track walk, contact your event organizer and ask if you can show up early to help setup the track. Riding around the track with someone who likely has 1000's of laps there is a fountain of knowledge.

Mike is dead on.
Get actual coaching. It's very different than HPDE instructors and way better that catalyst.

You dont even have a baseline. Odds are, you haven't even seen it done right. Just sitting 2 laps with a "real" coach with open you up and teach you a ton.

They'll also teach you to learn. You'll learn to watch your own videos and review your own data to find time.

I probably have close to 1500 laps at my track in multiple vehicles. I've probably had coaches 5 or 6 times at the very same track, let alone other tracks, and I still learn a ton every time I get a coach for the day.