GeneSplicer

iTrader: (14)

I've come off 5 pretty rough before, hopping to and fro a couple times! I wil say getting all over t5 is critical as it launches you on the nice fast downhill straight to t6. I typically use all of 5, 10a, 10b when required, hop over 3. Generally stay off strip leading into 5 (seems to want to suck you off track), and certainly never intend gators after 10b and coming into 12! Rob and I have to get on track at that same time - get that miata done!

Seefo

iTrader: (5)

quick question Rob, where do you do the braking for turn 5? My instructor was telling me to brake earlier than the right hand gator, get on it to get further out to the right and turn in. I guess I could do less braking, but do it earlier, and have a wider arc?

I just noticed that the miata ahead of you was braking right before the gator, but he did have a slight lock up.

Also, Steve/Collin, notice how he early apex's turn 1, tracks out just short of the left side gator, but still ends up in the middle of the track (Keeps about the same steering input)? DE guys tend to do a later apex (to the point where the apex is blind until you have already turned in), track out to just left of center track and drive much straighter up the hill.

m2cupcar

iTrader: (5)

I should have some video from this year's ARRC some time over the holiday that I'll post up.

T1 requires a lot of steering input in the beginning of the turn because it falls off camber about a third of the way to the apex after turn-in. So you turn in, then get some push/understeer, and then the track starts up hill which brings back the camber/traction. Knowing this, allows the driver to enter the turn with much more speed, which pays big dividends climbing that hill. But yes- like all turns, ideally you want to wind up at the edge of the track at exit (providing you don't need to set up for the next turn). That's the case in a low powered Miata where you have the entire hill to get back to the right to set up for T3. High powered cars actually have to set themselves up for T3 my controlling how far they track out from T1. Just don't forget that more steering input means slower speed- tires roll best when straight.

T5- brake early. Slow in, fast out as they say. It is so critical to get on the throttle as early as possible in T5 because it's all up hill. The reason I caught that guy coming out of T5 was because I was on the throttle five car lengths before him. He was still braking at the point where I had already been in the throttle for that five car lengths. And again, tracking way out on 5 means just less rolling resistance on the front tires with less steering input. You also want to do more steering at the slowest speed- which is your entry into the turn right after braking. In t5 it's critical to get this steering done so the car has more rotation which smooths the transition over the curbing. I wished I'd could say I manage that every time- I've hit that curbing fairly hard, fortunately it forces the car to rotate, after that it's just a matter of catching it with some counter steer so it stops rotating.

Keep in mind that as mentioned, these comments are for a low power car and as power increases, adjustments need to be made and some things become less critical. My lines are based on momentum. My goal is to minimize rolling resistance through reduce steering input and lateral Gs, while maximizing the time my right foot is buried in the throttle.

I would have come up last weekend, but my anniversary got in the way.

Gryff

iTrader: (6)

Yeah I see that. I feel like when I track out that far I end up scrubbing a good bit of speed. Rob, where abouts are you using as a turn in point? just as a reference. Russ was having me do exactly as you stated joe, I was always strait up the hill, left side of the car touching the dashed lines after the blend line. pretty far to the right.

Seefo

iTrader: (5)

I am not sure, I personally haven't been using the early turn in style like Rob has. I am NOT left side over the blend line, but sometimes if I can get enough rotation without too much fuss, I will have my right side close to or on the blend line. Othertimes, I cross over it. Anyways, for the turn 1 reference point, I usually feel it, but I turn in right where the track starts to dip in and cut out from under you. Do note though, I don't get all the way to left since the turn in point is the slight dip inward. So there is no need to be so far left in the braking zone. Plus you chance getting on the dirty parts of the track if you miss the turn-in by a hair if you stay on the left edge of the track.

(after tracking out) The really issue with being so far right is that you end up ******* up the turn in for 3, you really need to get as close as possible to the left gators in turn 2 to get turn 3 right (although instructors won't tell you to do that cause its a bit hairy for early students to do). Otherwise, you will cut the gator too early, and it will point at the escape route, rather than the sweeper.

I will try to get my fastest lap session up later tonight. I do have a bad tendency to fight the car tracking out on RA. I noticed that last time I was out since it caused me to spin in the rain, and I noticed it this time from watching Rob's video (especially turn 1 and turn 12).

Goes to show ya, got lots and lots to learn, just gives me more confidence that I can break the 1:50s next time around.

Gryff

iTrader: (6)

likewise for turn 1, not sure about turn 12. I dont feel like im fighting it much, I pretty much use all of the road and let it track out as it needs to.

I did say left didnt I, I meant right... derrrppp.
So you turn in when the track starts to cut out? or where it finishes? Im somewhere between these two points.

Definitely lots to learn! I just wish I could stay there forever and learn it all! lol

sixshooter

iTrader: (12)

I can't wait to drive on track again but I must. Funding is important and I need to restrain myself from trying to go to the track too often.

Gary and I talked about it and he is going to try to get his GT-R rebuilt for the NASA event at Sebring March 31-April 1. That is likely going to be my next track day since I can't afford to go often. Anyone interested in coming down should make it known here and start planning. We'll all get together if you want to. It is about an hour and a half from my house. That is approximately four months away if anyone wants to plan that far out. We can get rooms at the same hotel if you want.

Sebring is 1.2 miles longer than Road Atlanta and has more passing zones. It has both a complex series of turns and long straights. It really lets a low-horse Miata do ugly things to heavy cars in the curvy sections with lots of technical turns and sweepers, one after another. I actually enjoyed it much more than Road Atlanta from a driving standpoint just because there is so much to learn and so much more track to experience. There are 17 turns! It also means there is much less traffic because you have 1.2 miles more track to spread the field of cars over.

Just throwing it all out there.

m2cupcar

iTrader: (5)

For t1 I just drive a straight line from the left edge of the track and turn in right before the track cuts over for the turn (or I'd drive off). You can see this at ~2:30 in the vid. No steering prior to that. I think I'm apexing about as late as anybody- so when you say early, is the compared to steering into the turn some to follow the edge and then turning in? As far as tracking out, that's where the car has to go. If I held on to the steering input I have at the apex, the rear would come around. Traqmate data shows going into the turn @ ~90mph. With 105rwhp Spec Miata the car would actually lose speed coming up the hill with that entry. Fresh engine at 115whp and it would show nearly 5mph rise at the top.

Everybody I've ever taught/coached at Rd. Atlanta has the urge to hang on to steering input past the apex. I'd say that's only naturally given the potential results if you run off. The more seat time you have, the more confidence and the less hanging on to the wheel. And remember that keeping that wheel turned is sucking the speed from your life.

Seefo

iTrader: (5)

Well, two things really. You are 100% right, your apex point is just like mine! Your camera is just pointed slightly left and makes it seem earlier.

I did notice that I follow the outside edge, which is something I worked on before, but old habits die hard. Is the turn in point at that 2nd dip in the outside edge, or is it when the edge starts to turn in on you?

I am going to put my video up later tonight, let me get the editor fired up.

Gryff

iTrader: (6)

Likewise, I think this is also where I am getting hung up. I do have one lap where I feel like I did fairly well, and took a rather similar line to you rob, Im going to try to have a clip of it up soon. no idea when though.

Seefo

iTrader: (5)

Here we go:



8:07 is a good time to check out my turn one. you can I see I follow the outside edge there and turn in at the second dip. I will try the early turn-in (not apex) that you do. Turn 1 is turning out to be pretty similar to turn 6 in that case, except there is no braking zone right after one, its just we are told not to track out so far.

10:00 is the beginning of my fastest lap. Note how my exit out of 12 was compromised so much that I never got into 5th gear on the front straight. My 2-3 work was great, but my tun in 5 was kinda shitty.

(btw that camaro ahead of me is on slicks!)

GeneSplicer

iTrader: (14)

Since we're all asking Rob for input - where can I get shave some time? And please don't say Hoosiers - my pocket book can't afford them! THIS is what I wish this past weekend was like y'all - Joe didn't even get to feel what this car is really like - in fact I believe it was his extra 100lb weight that threw the car off balance from the awesome corner balanced car it was, that caused the trans to pop bouncing on top of the strip out of T5 - you owe me a 6spd Joe! Then again - you weren't technically even supposed to be in the car, so I'll let it pass this time
Mind you, I was only able to generate 10psi due to that cracked in half taco - I'm guessing maybe 200hp - 15psi gets me 230 before heat soak. Still pulled a 1:41.4 after pushing through T7 onto the straight with a cracked manifold - I should easily be in the upper 30's, I just don't have the ***** to pushing that hard yet...

Seefo

iTrader: (5)

how does me breaking your 5-speed mean that I owe you a 6-speed? MATH DOES NOT COMPUTE.

EDIT: Wait you ran a 1:41.x?? That means I was only off by less than a second. when you asked me what you ran I said I think it must be around 1:44-1:42ish! Can I get a cookie?

GeneSplicer

iTrader: (14)

Hehe - just because that's what I need! Working on vids from the weekend now - shouldn't take me long since there's only 2!

m2cupcar

iTrader: (5)

Track- Your line in T1 is a small turn to follow the track and then your primary turn in- so I understand now why you are saying I apex early. No doubt what you're doing is typically what's taught for track events to keep a comfortable cushion at track out. It's safe, but it's slow. I think you could definitely "graduate" to a race line through T1 - just take small steps and gradually increase your entry speed. I agree with your comments- being to identify mistakes is key, you can't fix 'em if you don't see 'em.

Bryan - I'll watch your vid and post back some thoughts when I get a break. Work pwns me right now.

GeneSplicer

iTrader: (14)

Here's Joe and I for a brief few laps... so if any of you ever break the connection post of the CAS (on the 1.6), this is what you'll see

Gryff

iTrader: (6)

^ I have lived that feeling all too well bryan! it was annoying as **** during a long drive...

Alright, heres my second to last session, but my best laptime. I know there is a lot more to give in a good number of places. My concerns are mainly T1, T5, T6 and T7. I feel like I can carry more speed through all of these. but I guess my main point is, how is my turn in for 6 and 7? Im doing the same as track at T1 I believe. Kinda following the left edge of the road, and almost making 2 turn ins. intead of one. But I may even be turning in later than him here.

m2cupcar

iTrader: (5)

Bryan- Keep in mind when reading my comments I can only tell so much from an in-car video. Like anything else, read it and use what works for you- because the individual driver and equipment have a lot to do with how a car is driven quickly.

T1 - Wait longer for turn-in. Use greater steering input immediately upon turning the wheel. Less input (what I see in your vid) at the beginning of the turn induces understeer that is carried through to the apex.

Ideally you want to do the greatest steering input at the slowest speed in the section with the most load on the front tires. As braking is reduced, and then throttle begins, load is moving to the rear and reducing the traction on the front tires and degrading the ability to steer. This is where "trail-braking" comes in. It's essentially blending the transition of braking-to-steering. As braking is eased off, steering begins before braking is totally removed. This way you retain some of the braking load on your front tires to maximize your traction for turn-in. This allows a higher speed entry and less speed scrub throught out the turn from excessive steering input.

Once you get the entry into to the turn right, you'll then feel the need for more entry speed since your front tires aren't fighting to stay on line nearly as much. Unless you're having trouble getting the car setup for the braking zone after turn 2 (for T3) you should be tracking out further for T1 and this will happen with more speed.

T2-T3 - Braking after T2 for T3 should be completed at the end of the strips on the left and turn in begins immediately with throttle input. This allows you to begin accelerating three car lengths earlier and take advantage of the downhill.

T5 - Similar to T3, complete braking at the end of the strips on the right (if you stay off them) and do more rotation in your turning immediately off the brakes where traction on the front tires is maximum. -OR- complete your braking before the end of the strips and use the curbing on the right for your turn-in (like I do). It's unsettling but it works. Traqmate showed a 2mph greater entry speed into T5 from this even though my braking zone was starting two car lengths earlier. Benefit at the top of the hill was 3mph increase onto the straight. I mentioned earlier that tracking all the way out across the strips to the cut-thru road is the quickest way (expanding the arch) with a suspension that will tolerate it BUT it's definitely more risk and rougher on the car. In a similar sense- late braking decreases your margin of error and you have to decide if it's worth the risk.

T6 - This looks similar to T1 where you have a gradual steering input that increases half way to the apex. Staying out to the edge of the track, more steering at turn-in and apexing later would allow more throttle earlier in the turn. T7 looked good.

Back straight - when you crest the hill at T8, you should drive a straight line to T9. It's 15ft shorter and you don't need to stay to the left to set yourself up for T9 - at least not until you're hitting 200mph down there.

T10a/b - This is a good place to practice the slow-in fast-out. Your entry speed into 10A is keeping you from getting on the throttle. You really want to aim for getting on the throttle right after turn in at 10a and increasing the throttle all the way up the hill. It's critical because the span between your turn in at 10A and the 10B apex is essentially a running start to get up the big hill. A greater speed at the top, means starting the downhill from the bridge at greater speed and that (again) is compounded all the way to the braking zone at T1. T11/12 - looks good

Considerations
- Use all the track. Staying as far out before turn-in and tracking out to the edge means that you reduce the amount of steering needed to negotiate the turn, that means more traction for greater speed, and less tire scrub.
- Remember that you can steer with the rear wheels using throttle. The benefit is two fold- you're accelerating and you're not actually turning (front) wheels and scrubbing speed. Straight tires are quickest.
- Braking needs to be done in less distance. Braking is not a linear curve. You ease into the brake pedal and then exponentially increase braking pressure. You CAN do this because the more load you place on the front, the more traction, which means you can add more load, get more traction and so on. That said, how late you brake is up to risk assessment.
- Slow in Fast out - you want to trade some entry speed for a greater benefit coming out of turn. A good example of this is T5. Going hot into T5 forces you to modulate your throttle as you steer through the turn. IF more rotation of the car was does earlier at a slower entry speed (comparative to your current) then more throttle could be added sooner in the turn without the modulation needed to prevent understeer. The benefit would be cresting the hill at a greater speed- and entering a straight away at higher speed has compounding benefits down the entire straight.
- One way to approach driving a track is to try and figure out how to straighten out all the turns so that they enable you to extend your "throttle-on" opportunities vs. modulating it, coasting or even braking.

Hope that will give you something to think about. - Rob

GeneSplicer

iTrader: (14)

That's it - your hired... Awesome info, thanks Rob!

sixshooter

iTrader: (12)

No kidding! I was drawing all sorts of mental pictures and diagrams while reading that. I feel quicker already.

Edit: Bryan, there are some good pics of your car posted by a professional photographer that was at the track on this site. http://www.art-racing.com/