Interesting stuff! The bit about going into turn 1 is particularly interesting, the more aero a car has, I would guess the more susceptible it must be to an unsettled chassis, especially if you're relying on ground effect. That chassis feel is another interesting thing, some people seem to be naturally aware of it, others are completely oblivious even when you try to explain it when they're driving, they literally have no idea what you're talking about even when you can feel it as a passenger.There is a thing called aero lull and it is a funny thing to get your head wrapped around.
The very first outing for me with something that had reasonable downforce was a Cosworth Spice at Road Atlanta. I normally slowly work my way up to speed for a given corner then stop when things start to move a bit. I came down the hill, made the last corner accelerated, then went to brakes to downshift a few gears and turn into turn one. I slowly raised the speed until the car started to move.
Bob Akin was up on the pit wall watching one of his customers in the only other Cosworth Spice there that weekend. When the session was done, he came over to my pits and asked me about turn 1. I explained what I was doing, that I was new to downforce and was feeling my way through things. He made a suggestion that, instead of accelerating then braking on the front straight that I simply accelerate to the speed I wanted to turn into turn one, carry that speed down the straight and then turn in using the same approach of adding speed till I was comfortable.
The next session I did as instructed and at the previous 107 mph at the apex, the car was ok and did not move. At 110 it felt better. By the time the session was done, it was 124 mph at the apex.
Bob stopped back by and said that looked much better and I was now within a couple of miles an hour of his guy. I asked him what had happened and he explained aero lull.
If a car is set up for something close to useable downforce levels for a particular track, there are times where you can start sliding around in a corner going a bunch slower than the car will actually go through the corner. In this particular case, Bob said I was upsetting the chassis with all the downshifting and hard braking only to let off and turn in. By simply caring the previous turn in speed down the straight, all that troublesome drama was gone and the car was perfectly happy to turn in at that speed. This gave me the confidence to add more speed and drive through that transition where mechanical grip is not enough and speed is not yet there for the aero to carry you through. He taught me that sometimes you need to drive through an aero lull. Six events later, I was on the car much harder much quicker and never felt the lull.
A very similar thing happened at Road Atlanta several years later in my Shell ChampCar. Trying to learn how to get through the kink flat without killing myself. I will never be Montoya and do not trust my hands to catch oversteer at 170. The solution was to set the car up to aero push like a pig through the carousel so I had to wait on the wheel the whole way through adding as much throttle as I could. I then carried a little more speed to the turn in for the kink and, having just felt aero understeer, knew the back end would not come around. The wheel got a little lighter through a few laps adding a couple of miles an hour each time then started to get harder. By the time I was done, I was go through the kink at 172 mph at the apex and 3.2 lateral. The downforce was so great that I had to wedge myself in the tub to turn the wheel. A bud who ran one of the teams showed me Moreno data from a test day a few months earlier and he was going through at 175 mph. I was ok with that; close enough for me
Third spring set up was next and, as everyone says, brakes were the last to learn. Those were some fun times learn stuff I had always wanted to know about.
I've got a reasonably good butt when it comes to driving and had little problem with my Chevron moving around under me. When I got into the faster stuff, I lacked the attachments to let the cars move much. As I moved up the ladder in hardware my lap times dropped and I left more and more on corner exit. Pure amateur hour but oh so much fun.
Haha, I'm the opposite, I like the car to move! I want to find out if that changes when I'm in a 4G corner!
great post Lola as always...There is a thing called aero lull and it is a funny thing to get your head wrapped around.
The very first outing for me with something that had reasonable downforce was a Cosworth Spice at Road Atlanta. I normally slowly work my way up to speed for a given corner then stop when things start to move a bit. I came down the hill, made the last corner accelerated, then went to brakes to downshift a few gears and turn into turn one. I slowly raised the speed until the car started to move.
Bob Akin was up on the pit wall watching one of his customers in the only other Cosworth Spice there that weekend. When the session was done, he came over to my pits and asked me about turn 1. I explained what I was doing, that I was new to downforce and was feeling my way through things. He made a suggestion that, instead of accelerating then braking on the front straight that I simply accelerate to the speed I wanted to turn into turn one, carry that speed down the straight and then turn in using the same approach of adding speed till I was comfortable.
The next session I did as instructed and at the previous 107 mph at the apex, the car was ok and did not move. At 110 it felt better. By the time the session was done, it was 124 mph at the apex.
Bob stopped back by and said that looked much better and I was now within a couple of miles an hour of his guy. I asked him what had happened and he explained aero lull.
If a car is set up for something close to useable downforce levels for a particular track, there are times where you can start sliding around in a corner going a bunch slower than the car will actually go through the corner. In this particular case, Bob said I was upsetting the chassis with all the downshifting and hard braking only to let off and turn in. By simply caring the previous turn in speed down the straight, all that troublesome drama was gone and the car was perfectly happy to turn in at that speed. This gave me the confidence to add more speed and drive through that transition where mechanical grip is not enough and speed is not yet there for the aero to carry you through. He taught me that sometimes you need to drive through an aero lull. Six events later, I was on the car much harder much quicker and never felt the lull.
A very similar thing happened at Road Atlanta several years later in my Shell ChampCar. Trying to learn how to get through the kink flat without killing myself. I will never be Montoya and do not trust my hands to catch oversteer at 170. The solution was to set the car up to aero push like a pig through the carousel so I had to wait on the wheel the whole way through adding as much throttle as I could. I then carried a little more speed to the turn in for the kink and, having just felt aero understeer, knew the back end would not come around. The wheel got a little lighter through a few laps adding a couple of miles an hour each time then started to get harder. By the time I was done, I was go through the kink at 172 mph at the apex and 3.2 lateral. The downforce was so great that I had to wedge myself in the tub to turn the wheel. A bud who ran one of the teams showed me Moreno data from a test day a few months earlier and he was going through at 175 mph. I was ok with that; close enough for me
Third spring set up was next and, as everyone says, brakes were the last to learn. Those were some fun times learning stuff I had always wanted to know about.
MB, thank you for the kind words.
