PCA SDR

Can someone please explain to me the best way to get through turn 9 at California Speedway in a 911? I think I tried ten different lines, but none of them worked very well.

My best exit speed (110 mph @ Suzuki bridge) was attained by late braking, trail braking to rotate the car, then catch to accelerate past a late apex. However, the bump field leading into turn 9 made this a very low probability technique: I spun 180* the third time I tried this move.

I then went back to brake early in a straight line, turn in tight to a middle apex and then accelerate to track out. I also tried late braking in a straight line almost to the track exit and then turning in for a very late apex, but this was not any faster. Both of these yielded 107 mph @ Suzuki bridge.

TIA.

That is one of the toughest corners I have ever driven and waiting pays big dividends down the subsequent straight.

You might notice that the shape of the corner is odd. I first realized this back in 2002 when one Thursday evening some buddies and I went up on the banking in between turn 1 and turn 2 and saw just how strange a corner (and the approach to the corner) really is.

The track actually falls away as you enter the corner making it doubly hard. I have always found, that if you can brake straight and late through the odd part of the approach and slow down enough and pitch the car slightly, not much just help you turn in a bit and late apex the corner, you will get a speed of around 115 to 118 mph before the brake zone in a 3.6 normally aspirated motored car. I would need to look back at my data but I believe that was the speeds I was able to achieve there if I set up turn 9 correctly.

If I did not set the corner up correctly the speeds were down below 110 or right there. Thus losing precious time.

Hope this helps.

I found 9 to be double trouble. I caught a lot of cars by holding full throttle through 7-8 and into the braking zone of 9. What I found is that people would crack the throttle through 7-8 and coast or part throttle into 9. It wasn't late braking that caught them, it was the extra second of acceleration. That was all wonderful, but then I had to get the car slowed for 9 AND get a good exit from 9 for the second fastest straight on the track. The best route I found was to brake straight to the outside of the track. When I saw the oil slick which was on the outer edge of the track, I turned down to the apex. This allowed good straight-line braking, straightened the corner out as much as possible and allowed for a late apex. It did however make the turn-in sharper and likely lowered corner speed a little. It was the best trade-off that I could come up with. I think I tried it every way but with a spin. Now only if I could find some way of knowing for sure which way was faster... G2X

bibbetson wrote:I found 9 to be double trouble. I caught a lot of cars by holding full throttle through 7-8 and into the braking zone of 9. What I found is that people would crack the throttle through 7-8 and coast or part throttle into 9. It wasn't late braking that caught them, it was the extra second of acceleration. That was all wonderful, but then I had to get the car slowed for 9 AND get a good exit from 9 for the second fastest straight on the track. The best route I found was to brake straight to the outside of the track. When I saw the oil slick which was on the outer edge of the track, I turned down to the apex. This allowed good straight-line braking, straightened the corner out as much as possible and allowed for a late apex. It did however make the turn-in sharper and likely lowered corner speed a little. It was the best trade-off that I could come up with. I think I tried it every way but with a spin. Now only if I could find some way of knowing for sure which way was faster... G2X

yes that will tell you, see my post above hehehehe

Kris:

I treat it as classic Type-I - Brake in a straight line, maybe a bit of trail-brake to rotate, then on the gas WAY before the medium-late apex.
I'd usually upshift to third just past drifting out to the gators on the left.

I didn't find anyone in my group who seemed to do it better - I either pulled them or caught them early on the straight, and often all the way to Turn 12.

I'll attempt to digitize and post some video in a few days, FWIW.

Now, this was my best corner, but take it with a grain of salt - I didn't turn a 1:50.sumpin. In fact, I didn't turn anything at all!

Kris,

Unless you are racing, in which it opens the door for stupid moves that won't work, I agree with Bill. Close your eyes and the car should stick flat out through 7-8 and you will NEED to keep on the gas well into 9 to balance it for straight line 100% braking into the left corner of the turn, turn tight and full gas way before the apex ideally catching the slightest wisp of dirt at the end of the gators on the track out.

kary wrote:That is one of the toughest corners I have ever driven and waiting pays big dividends down the subsequent straight.

You might notice that the shape of the corner is odd. I first realized this back in 2002 when one Thursday evening some buddies and I went up on the banking in between turn 1 and turn 2 and saw just how strange a corner (and the approach to the corner) really is.

The track actually falls away as you enter the corner making it doubly hard. I have always found, that if you can brake straight and late through the odd part of the approach and slow down enough and pitch the car slightly, not much just help you turn in a bit and late apex the corner, you will get a speed of around 115 to 118 mph before the brake zone in a 3.6 normally aspirated motored car. I would need to look back at my data but I believe that was the speeds I was able to achieve there if I set up turn 9 correctly.

If I did not set the corner up correctly the speeds were down below 110 or right there. Thus losing precious time.

Hope this helps.

I did not notice when driving it, but when I went out to watch one of the club races there I could see that the exit of 9 was 8-10 feet lower than the entrance.

On my fastest lap, my braking zone speed was just over 121.

Jad wrote:Kris,

Unless you are racing, in which it opens the door for stupid moves that won't work, I agree with Bill. Close your eyes and the car should stick flat out through 7-8 and you will NEED to keep on the gas well into 9 to balance it for straight line 100% braking into the left corner of the turn, turn tight and full gas way before the apex ideally catching the slightest wisp of dirt at the end of the gators on the track out.

Flat out through 7-8 is easy for my car, it is the braking on the bumps that was so difficult, particularly with my first generation ABS that kept thwarting my efforts.

Thanks for all the answers. It seems like the consensus is brake hard and straight, turn in and get back on the gas. Looking at my data, this is exactly what I did on my fastest lap - go figure!

I have raced this track sevral times and when racing, the line always changes and therefore, there is no correct line.

Now, if you are in a TT or DE, I would go back to my first time on the track in a DE in my 914. If I stayed inside braking into 9, I would beat the 993's to the turn and take a sip from my water bottle waiting for them to get through so I wouldn't get flagged for passing in a "No Pass Zone". Then of course, I would race them to the next turn to repeat the process

I think slow in and fast out is is quicker, with less chance of showing your nose to the car behind you or checking the height of that new lawn they worked all week on. 911's if not set up correctly will tend to push through a turn like that at speed.

Awe, what do I know

Kris,

You don't need any tips, you drove very well. It sounds like you are making good use of the new data acquisition system.

martinreinhardt wrote:Kris,

You don't need any tips, you drove very well.

Thanks, I take that as quite a high compliment coming from you. I am still in awe of your club racing results - nice work!

martinreinhardt wrote:It sounds like you are making good use of the new data acquisition system.

Some. There is so much info there that it is hard to figure out what to isolate and compare. I'm sure over time it will be quite valuable, though.

Bill Addy wrote:I have raced this track sevral times and when racing, the line always changes and therefore, there is no correct line.

Now, if you are in a TT or DE, I would go back to my first time on the track in a DE in my 914. If I stayed inside braking into 9, I would beat the 993's to the turn and take a sip from my water bottle waiting for them to get through so I wouldn't get flagged for passing in a "No Pass Zone". Then of course, I would race them to the next turn to repeat the process

I think slow in and fast out is is quicker, with less chance of showing your nose to the car behind you or checking the height of that new lawn they worked all week on. 911's if not set up correctly will tend to push through a turn like that at speed.

Awe, what do I know

An inside line is interesting, and one that I did not think to try. How are the bumps in there? If it is a lot smoother, that could be quite an advantage.

bibbetson wrote:I found 9 to be double trouble. I caught a lot of cars by holding full throttle through 7-8 and into the braking zone of 9. What I found is that people would crack the throttle through 7-8 and coast or part throttle into 9. It wasn't late braking that caught them, it was the extra second of acceleration. That was all wonderful, but then I had to get the car slowed for 9 AND get a good exit from 9 for the second fastest straight on the track. The best route I found was to brake straight to the outside of the track. When I saw the oil slick which was on the outer edge of the track, I turned down to the apex. This allowed good straight-line braking, straightened the corner out as much as possible and allowed for a late apex. It did however make the turn-in sharper and likely lowered corner speed a little. It was the best trade-off that I could come up with. I think I tried it every way but with a spin. Now only if I could find some way of knowing for sure which way was faster... G2X

In a 944 GP class car, you drive it much like Bill-eye ... except stay longer on the throttle after 7 & 8 and brake straight to the way, way outside before turning in. With such low power in a N/A 944 the trick is to find the right gear for the corner: second gear screams to redline and 3rd bogs a little before the rpm's hook into power ... at least on 17" rims/tires. The secret ... as Bill mentions ... is staying on the throttle after 7-8 and ... as Jad mentions .... settling the car solid before applying the brakes really hard and straight. Then it's ... trail-off the brakes as you turn in and get on the throttle early and throttle steer throught the apex. My fastest times in the 944 was a brake-to-the-outside-and late-turn-in for mid-to-late- paex (As Paul Y. mentions). all other lines ... especially in a heavy low-powered car ... were slower. And ... since there is no time to be gained on the front straight or Turn 1 /turn 2 in a N/A 944, the speed and best times only exist in turns three through 14, IMHO. Everything else is just waiting .... and waiting .... and waiting .... oh yeah, and a lot of point-by's.

Just my experiences.

kurquhart wrote:
Some. There is so much info there that it is hard to figure out what to isolate and compare. I'm sure over time it will be quite valuable, though.

Kris,
Try not to focus on fastest lap, look at all laps in comparison to segment times and determine certain segments you did well in. It will be the case that an overall best lap time might show a poor turn 9 therefore you did well to make up for it elsewhere. This is the deceptive part of data acquisition. So for turn 9 (and others) I suggest that you look at that segment time for all your laps to see if you did something that was faster than your best lap segment time in another "slow" lap. Often they are there just hard to see.

You can also compare the relative line between two laps to see how you approached the corner which is also valuable.

Did you try different lines through turn 1 and 2 to see what was fastest MPH and segment time? This another great use of the data as well.

Call me if you have questions on how to obtain and compare this and other data to improve your times.