Matt Romanowski

Or post up some of your data and see where other folks see time in it.

JackOlsen

Thanks.

On the aero, I won't claim any expertise, but I did work for about a year with a very generous aerodynamicist who created a computer model of my specific car and tested a bunch of different possibilities for it. The duck/wing combination tested well. Interestingly, the performance dropped off pretty significantly if the wing moved either 4" down closer to the duck ot 4" farther up and away from it.

I believe that the end caps are able to reduce 'spillage' from the high pressure areas to the low by extending both up and down (and McBeath's book supports this, at least as I understand it), but that the gain for caps going up above is almost always outweighed by the advantage of keeping the wing up as high in the air as the rules will allow. But you are completely right about there being more benefit from moving the leading edge of the cap forward of the leading edge of the wing and also of a different shape than mine. The shape of the larger ones I came up with had a lot to do with the piece of scrap aluminum I had on hand.

It would be great to get access to a pro's data, and even better to have a pro drive the car with the logger running. But hiring anyone for the day would burst my budget.

I realize it's not a simple matter to look at one of my laps and go: fix this; there's your second. But any advice at all can help, and there's an off chance that a Willow Springs regular will look at this thread and offer some advice that does as much for me as my (mostly accidental) discovery that I was leaving time on the table in turn 9.

I'll try and dig up that data file for that lap and post a basic graph here.

JackOlsen

The data.

jrgordonsenior

Sssshhhh.... I noticed that too on those same turns (3/4). It seems many racers hang out late at both 3 & 4 and I can't figure out why. There's no reason to late apex there especially T4.

Jack you nailed both T1 and T2 at entry and really got T2 through the sweeper on your fast lap video. Very impressive and you should be faster when you dial in your Ohlins. BTW did you change spring rates with the new shocks?

I saw 2 things you could try...... You short shift just before the apex of T6 at 5600 RPM but your other shifts are at 6600. Was that because of the bump? If that's your concern, and I've floated valves there, try waiting until the car gets light over the top to shift. You can hear Safronas's Audi wind up as he goes light there, I guess he has strong valve springs and axels. You might gain an additional 500 RPM shifting over the top which should make you faster down that back straight into T8 and subsequently into T9.

You only carried 101-102 into T9 on your fast lap video and I didn't hear you get back to throttle until after the apex. That's the one turn you either have to rotate under late breaking in the middle of the track, or hang out on the outside to nail a late apex. Either way, if you can get back to throttle sooner I'll bet you lose another second perhaps 2....

Oh and you're right about the weather affecting lap times there. Almost all POC's track records there are set during our annual early December race event when it's cold and usually without wind. Only 2 weeks until that event, you should join us.... https://porscheclubracing.org/calend...tration/?ee=54

PS: A 7-cup should be in the 23's there in decent weather. I've seen 21's from 10's and later....

JackOlsen

Thanks, JR! It's nice to get input from someone significantly faster than me who's very familiar with Willow.

I did a slight spring change with the Öhlins -- but it was going softer in front. Hayden thought my rear rate should stay the same (550#).

I will definitely try putting off the shift over six to late, rather than early. The wisdom of not wanting to shift where the car is light has always made me short shift there, but I'll try pushing it back. My car doesn't get particularly light there.

And turn 9 has always been too easy for me -- but not in a good way. I've just never pushed the car particularly there. But as I think I mentioned, the drop from 1:27.5 to 1:27.09 came from 'accidentally' carrying too much speed through there (at the very beginning of the clip), and I honestly believe I can carry even more at the apex by doing what you say and getting on the gas even sooner.

I pulled just turns 3 and 4 from Sofronas' 1:19 lap in the WC Spec Audi R8, and it's probably the segment of the track where I'm doing my best against him. I would take the numbers with a slight grain of salt because grabbing the exact same piece with two different camera systems is very tricky. But according to the segment I did pull, I'm only .04 seconds behind him from the entry to 3 to the apex of 4. After that, of course he destroys me. But I think it makes for some defense of my unconventional line there. (His line is actually pretty close to mine, compared to most fast 911s). If you broke the track up into 8 segments, he averages a full second ahead of me in each of them.

Here's the clip:

Matt Romanowski

Your first and third braking spots (there is no distance to reference on the graphs) could be quicker on the application. That would probably net you .2-.4 seconds.

The data also looks like you have a little bit left on entry, but your driving is overall very good.

JackOlsen

Thanks! I'm making a list -- and I'm going to try to get out for an open testing day in mid-December. There's a real benefit to not having a line of students and other distractions. I should be able to get some decent data and better records of track conditions and setup changes. If it's cold enough, I might even get a shot at my 1:26.

Matt Romanowski

Can you post a file of your best lap and one of your more average laps? Sometimes that is a great way to see where there is some time to be had.

JackOlsen

Sure.

Here's a 1:29 and the 1:27.

James-GMG

Jack,

I have some data from earlier this year testing in the Audi R8 with a 1:17.8 and a 2010 Cup lap of 1:19.2 if that would help.

ProCoach

Yes, sir! James, that would help! MoTeC?

JackOlsen

They would both help in reminding me of just how low a place I occupy in the Willow Springs food chain, but yes.

But of course, I would love to see what that kind of data looks like. I use the Race Technology software, but I'm sure that the data in CSV format would be something I could import. (email to olsenjack (at) gmail.com )

Thanks very much for taking a look at the thread. I'm crossing my fingers now and hoping that I didn't screw up the spelling of your name.

ProCoach

That's the idea. To export in .csv the Race Technology file and export James' file to .csv, then plot the difference in as many ways as you can.

The GPS data would work to allow plotting of lines...

2BWise

I'd concur with Matt here. Getting onto the brakes way too slow into 1. Trying stabbing the pedal quicker and instead of increasing pressure trail into 1 a bit more. Looking at the speed trace it goes pretty flat mid corner in 1. It looks to me that you could trail into 1 more and bring the speed down to the apex speed a bit more gradually (overlapping Ax and Ay more significantly). In the data it would look as though you rounded off the corner in the speed trace.

Matt Romanowski

Check out a couple more notes. Overall, you carried more speed just about everywhere. Where the ambient conditions similar both days?

Did you make a conscious effort to go faster or was this just a lucky session?

In the video, it looks like you have more track to use on the right side of the car on right hand corners. It could be the camera angle, but it looks like your off the apex by a ~2' many times. Is it the camera angle, speed, or by plan?

Why don't you use start/finish as your lap marker?

I'm not familiar with the Race Technology software, but will it give you a best rolling lap? If so, what is your best?