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07-07-2011, 07:26 PM | #1 |
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Please Critique my Lines!
I'm posting this because I know alot of people here autocross and track. I've always wanted help and I want to improve and become a better driver. I can provide a paint drawing of the course map if you need it to better comprehend the video.
I'm posting my clean fastest run and my fastest run +1 cone (that I barely nipped mind you). I need to shave time and the only way I think I can do that is improve my lines. I know they aren't perfect, and I want to change them now before I get into a bad habit. Best Clean Best + Cone I want suggestions and critiques. Please don't hold back |
07-07-2011, 08:36 PM | #2 |
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I think your main issue is that you're way late on pretty much every slalom cone. By the time you get to a cone, you want the car already turned enough to be at least parallel to the direction of the slalom, preferably already turning around the cone. This is called being on the "backside" of a cone. You are waiting to get to a slalom cone before turning around it. The problem compounds with every cone, so the problem gets worse as you go through a slalom. This issue also causes you to get progressively wide on each cone. You get hammered by this on the curving slalom on both runs. On your fast run with cone, the slalom at 1:05 is much better. You don't get as late, carry more speed and don't get stuffed at the end. You're also much closer to the cones. Also much better on the finish slalom on the cone run.
On a few of the pivot cones, you go in too tight to the cone and too fast, and way overshoot the apex. That sort of thing costs a HUGE amount of time (like 1-2 seconds each time you do it). I suggest going in wider, turn in earlier and try to place the car so you are within ~1ft of the cone at the apex. You'll carry more speed through, and drive a shorter line. Examples of this are the pivot at the end of the first slalom, the end of the curving slalom at 0:50, pivot at 0:55, the end of the sweeper at 1:20 and again at 1:27. The sweeper at 1:40 is way better, as is the entrance to the curving slalom. You don't overshoot and therefore don't have to stomp on the brakes and slow to a crawl to make the corner. This issue is helped by "looking ahead". In this case, that means that before you even brake for a corner, you should already be looking at the EXIT of that corner. Before you get to a slalom, you should already be looking at the END of the slalom. This sometimes means your head is turned 90 degrees from the direction the car is moving. This will help you get your braking point right, turn in at the right time, get the car on the right line from the beginning, get your speed through the corner right etc. etc. It's probably the most important thing (and hardest) to learn to do. I still struggle with it, and find myself staring at the tips of my shoes sometimes. I'm sure someone better than me could find you more time. I'm a hack. Because of that, I STRONGLY suggest that if you have the chance, you take one or more Evolution schools. I've taken the Phase I, Phase II, Challenge and Setup schools. Phase I in particular is the best $250 you will ever spend autocrossing. The instructors are all national champions. Most are multiple time national champions. You could spend 10 times as much on your car and not get even a fraction of the gain. They will teach you to look ahead. Last edited by cgroppi; 07-07-2011 at 08:47 PM.. Reason: grammar |
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07-07-2011, 09:03 PM | #3 | |
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I noticed the first time I went out I always hit the slalom cones with my rear wheels if I took the same line that I did with my E46 (that's my cone hit as well). How can I make sure I turn in early, and get my nose pointing in the right direction without clipping the rear? The bad thing was that my "best run" was my second heat. I ran a 86.6xx but I murdered cones by going too fast into the second optional slalom (I hit a cone prior and knew it was a throw away run). I can post this video if you want to see. I am still trying to get use to this car and see exactly how fast I can get into and out of the slaloms, and everything else. This is only my 3rd time out in the car. When turning on the pivot cones, should I take more of a "corvette" line? Take it wide then straighten it out to almost a straight line to hit the apex? I really do need to look MORE ahead. I will look ahead, but not to the extent that you mention at all. With the purchase of my car, I missed the opportunity to do the Evo school this year. I plan on getting my butt to one of them though. I know how much of an improvement it can cause. Here is a Paint MAP of the course. Hopefully this can help you try to show me what you mean when I approach the pivot cones. |
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07-08-2011, 09:41 PM | #4 |
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First of all, great job getting out there with the car and not treating her like a garage queen!
I'm noticing that the Z4M has good acceleration, so I can brake harder later and not have to worry about carrying the speed because I can roll back onto the throttle hard and make it up. So, in general I'm fast in, slow out for turn arounds, c-boxes, etc. What camber and tire pressure are you running?
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08 Z4MC /// DKF Exhaust, Stoptech 6/4 BBK, TCK Coilovers, Strong-Strut, Apex EC-7's, APR Splitter/Wing, AFE Intake, Underdrive pulleys, AS SSK, Jaffster, UUC Tranny Mounts, Matte Grill, RPI Scoop, CF Badges |
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07-08-2011, 10:13 PM | #5 | |
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Camber I have absolutely no clue on. I'll need to get it re-done to my preferences...as I just got this car in March (suggestions? Should I remove the front pins) I found that tires like 34 PSI, all around. I seem to get good temps from the inside out and I'm getting the marks right at the wear-bars (I'm using shoe polish to mark the tires). I usually start the tires at 35 PSI, get a run in and them drop to 34 PSI. From there I use a sprayer to keep the tires cool and they maintain at 34 PSI. I bought an extra set of 224s and I'm waiting to purchase some Hankook RS3s |
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07-08-2011, 10:44 PM | #6 | |
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I also aligned with about 3/8" total toe out in the front. I reduced the rear camber to about -1.5, and kept the resulting loss in rear toe in (I can't remember what the number is exactly). You'll notice a big change when you get off the stock contis and onto RS3s. The Contis are just about the worst tire I've ever had the displeasure of driving on at an autocross. I chunked an entire tread block off one of the fronts in 7 runs. |
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07-09-2011, 12:18 AM | #7 |
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For the slalom, I think you just need seat time. Hitting cones because you're early on them is not that bad of a problem. Being late is. Just try to get the car on the backside of each and every cone, especially the first cone in the slalom. If you hit cones, you hit cones. That will eventually go away as you learn the car.
As an example of a line into a pivot, see the attached video at 0:34 entering the slalom. I approach relatively widely, turn in early, and place the car relatively close to the cone, but I am driving a constant radius arc through the corner. You don't want to break it up into "turn-straight-turn". Not that this run is perfect or anything. I could make a long list of mistakes, and I know I wouldn't catch them all. Last edited by cgroppi; 07-09-2011 at 12:36 AM.. |
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07-09-2011, 02:37 AM | #8 |
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not so nervous with the throttle, smoother is faster.
take the turns wider and faster and stop the rattle from your keys ... less rattle -> more concentration -> faster ;-) don't drift ... keep the car a little bit before you're drifting What's about your sitting position? The background-noise sounds like you are working hard - very hard with the steering-wheel. regards, Frank |
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07-09-2011, 09:15 AM | #9 | ||
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I sit as far up as I can without my helmet hitting the roof and forward to when I lay my hands out across the steering wheel, my wrists are on the steering wheel. |
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07-13-2011, 12:40 PM | #10 |
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Just like the last guy said, be smooth on the throttle. Don't jump on and then pull right off. Try going to half or 1/4 throttle instead of full off. This will keep the rear planted better.
Also, get a helmet cam so we can see the track easier. Watching that video, I had no idea where the track was half the time. Helmet cam lets us see what you see. One last thing, try not to put your foot to the floor until your steering wheel is straight. |
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07-18-2011, 10:32 AM | #12 | |
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I only noticed three things: At around 0:40 in the curving slalom, you straight-line through the cones rather than drive the slalom. This ends up slowing down your entry into the sweeper following the slalom. It's usually better to drive a slalom even if you don't have to. At 0:50 it looks like you enter the sweeper too hot and the car seems to push a lot. Your exit into the wallom at the end is pretty good, though. Maybe this criticism is bogus. It's hard to tell from the video. There are a few places where you coast for a second (the start, 0:17, 0:25). I'm terrible about this. You want to be hard on the gas, transitioning to hard on the brakes with no coasting in between. All our local hotshoes are always yelling at me for screwing this up. Another suggestion is something I'm trying to get better at. One of our local national champs who also drives a bmw (a DSP 330i) is always pushing me to choose the line that lets me get on the gas earliest and hardest coming out of a corner. High power cars with good LSDs (i.e. the M coupe) have the biggest advantage under acceleration, so it's best to use it. I can't see any specific ways to improve this on the video, but it's worth keeping in mind. |
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07-18-2011, 07:43 PM | #13 | |
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I did push really hard at the end of the slalom at :50. I tapped on the brakes and the car bit again. I was topping out at second gear at the end of the slalom and it was my last run, I was trying to squeeze as much as I could get. I noticed those lifts as well. It certainly doesn't seem like that when you're driving. |
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07-18-2011, 09:14 PM | #14 | |
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And no, I never notice those little lifts either while driving. Which is why they're so hard to get rid of. Doing that costs a tenth or so each time, so it's worth the trouble to try. |
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07-19-2011, 05:12 PM | #15 | |
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Thanks for the advice. |
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