Da Groj

I love using the youtubedoubler. Makes you see where you lost/gained time compared to everyone else. I tend to notice a good difference between the lightweight tiny cars compared to the heavier on the lines they take. Also, how much less braking they need to do.

Loren wrote:

dbeng wrote:Anyhow - I would welcome any feedback on my run...

I took Doug's suggestion and doubled the video:
http://youtubedoubler.com/n9Ct

That's pretty interesting. You're not really losing anything on the entire outgoing side. Backing up my thought on the turn-around above... I think I'm getting a better exit on the turn-around, getting on the gas earlier, and hitting those first couple apexes on the return side harder. If I'm looking at it right, it really looks like most of that 2-second difference is right there. We're pretty much even right up to the apex of the turn-around. But, by the first "in-and-out" maneuver on the return side, I'm nearly 2 seconds ahead. Pretty surprising that it all happens in such short space.

Thanks Loren, that's helpful. I will take a closer look at it when I have some more time. I definitely lost time in the turn around - I wonder how much of the difference is due to taking an inferior racing line and how much is due to inherent cornering speed differences due to my heavier car with less optimum suspension tuning than your Mirage? Also there's Dan E's patented inches to mass ratio to consider, but that might be fairly close since my car is heavier but running wider tires.

Carracer wrote:Best run I have on video:

https://youtu.be/I-JczZfOOQ8

My 42.074 was done in Sally's car ( thanks again! ). I keep forgetting the B in NB stands for "Better" and my car just isn't fast. Still very happy with my last 2 runs. The 42.595 felt like I got a lot of out of car.

I guess my approach to the turnaround was slower... I was keeping it tight to the end of the wall but it looks like the faster folks were hammering it out past the end of the wall and track out to the grass... Maintained more speed and made for an easier/earlier exit, too. That, and I was braking in spots I didn't need to towards the middle of the return side. Easily worth a second!

And Philip, nothing that's wrong with your car is an NA problem! Shocks, diff, sway bar... all can be fitted to an NA just fine.

Pictures!
Big thanks to Dan and Mike for spotting for me.
https://flic.kr/s/aHsmehkJ6g
Most of run groups 1 and 3 are covered and a bit of 4.

jaball77 wrote: And Philip, nothing that's wrong with your car is an NA problem! Shocks, diff, sway bar... all can be fitted to an NA just fine.

It would be cheaper to sell my car and get an NB than convert my car to an "SCCA legal" legal car with a diff. And even then without doing an R conversion it won't be as competitive as an NB.

Hate to say it, but I wasn't wowed by the photos from the previous event. Too much blurred background, couldn't see the cones. Back on point for this event, though. These photos are awesome!

So this is neither Loren's or my fastest run...his 44.0, my 44.3. Have to conclude I'm just not pushing the car hard enough now that I'm on fresh, wider tires. There are spots I'm clearly ahead...and then I give it back. Have to cure that before Dixie.

http://youtubedoubler.com/?video1=https ... Name=Loren

Great pictures as always Philip. The 1st and 2nd owners of the Z love seeing these. Thank you!

I wanted to compare my 44.0 to Philip's 42.5. But, with vastly different camera positions, that's hard to do.

So, instead, I did a data point analysis similar to what the guys with the fancy high-res GPS data (Philip, Jamie, etc) are doing. I just picked some points on the course, and analyzed the videos on YouTube to get rough times within a second. (I could have loaded the videos up in a video editor and gotten more accurate times)

Here's what I came up with for elapsed time per segment:

LW-PP-Segment
0 - 0 - Timer
7 - 6 - First Slalom Cone
10- 9 - Left Apex
4 - 4 - End of Wall
6 - 7 - Exit Apex
7 - 6 - Entry of In&Out
4 - 5 - Last Left Apex
5 - 4 - Final Gate
2 - 2 - Finish
45-43 - Total Time

Now, these times are just to the nearest second. But, that's close enough to identify where most of the 1.5 seconds difference between our times was.

Philip gained a second right off the start. That makes sense. 0-45 acceleration, he's surely got my be a second.
Philip got through the slalom maybe a second faster than I did. Again, no surprise. Philip is merciless.
We both got from there to the end of the long cone wall in about the same time. Good.
I'm a little surprised that I got through the turn-around slightly quicker than Philip did. It shows as a second, it's probably a lot less than that.
Philip gained that time back accelerating out of the turn-around to the first wiggly big. That's probably 25-50 acceleration in 2nd... not exactly my car's strong suit.
Through the wiggly bit... I was somehow maybe slightly faster.
The rush through the last right-hander to the final gate, Philip pulled ahead again. Being Philip, he probably just didn't slow down for it as much as I did. He probably didn't slow down at all.
The sprint to the finish was the same. That's probably 45-55 acceleration. Neither of us do that very well!
And the total time from the segments comes to within a second or so of our actual times, so I didn't stack errors and get too far off.

Not terribly scientific, but interesting. The only place Philip clearly out-drove me was the slalom. And I got through a couple segments maybe a tiny bit faster than he did. The rest was lost in acceleration. I'm okay with that.

Loren wrote: I'm a little surprised that I got through the turn-around slightly quicker than Philip did. It shows as a second, it's probably a lot less than that.

My theory that I tell anyone that will listen, most won't, eyes glaze over, is that in a steady state turn like the turnaround it is pounds/mm of tire. You car probably has less lbs/mm than Philip's.

If you're driving the proper line and cornering at the limit, there's something to that, Joe.

Of course, I'm mostly cornering on 3 tires, which reduces my total contact patch!

Loren wrote: Wed Mar 14, 2018 4:29 pm I'm a little surprised that I got through the turn-around slightly quicker than Philip did. It shows as a second, it's probably a lot less than that.

I'm thoroughly enjoying the deeper dive into comparing runs - and can conclude that Loren was the king of the turn around! I put together the comparison of my fastest run 45.87 against Loren's 44.09 using my phone camera as a better visual comparison between the two. So where does Loren make up the 1.8 seconds? A huge chunk of time exiting the turn around and kept pulling away the whole return side of the run. I synced the videos at the first sight of the nose lifting under acceleration off the line.

I get a huge advantage off the line accelerating into the slalom (aint no substitute for cubes), Loren starts to make it back throughout the outward leg until we are almost exactly equal entering the turn around. By the time we make the first left hand kink immediately after the turn around Loren is noticeably ahead and it only gets worse (from my point of view) from there on. Quite incredible that the entire time advantage was pulled out on the return leg:

https://youtu.be/cIDHvNtjFIU

Dan

Looks like you were late on pretty much all the cones on the first half of return side, then good on the middle slalom and than late entering into the final kink. Doesn't look like Loren was ever late.

I was unaware of youtubedoubler until this thread. I compared mine to Philp's run in his car and concluded, like Jamie, that I didn't push as hard. I've been trying Lauren's momentum approach so I was just trying to stay smooth on the gas and avoid having to get hard on the brakes on turn in. Where as Philip's run leads me to believe he knew exactly where and how hard to throw his car around to hold the speed. It's pretty darn impressive.

P.S. Has anyone considered the possibility that the zip tie momentum is not a result of but the cause of his car's patented sway?

I can never pay attention to Phillip's videos. I always watch the zip ties.

I had a great time as usual. Love the videos, you guys are quick!

Here's another, not as quick
https://youtu.be/Ke5u3OjZ_RU

I also did not know about youtube doubler, that's pretty awesome.

Loren wrote:I wanted to compare my 44.0 to Philip's 42.5. But, with vastly different camera positions, that's hard to do.

So, instead, I did a data point analysis similar to what the guys with the fancy high-res GPS data (Philip, Jamie, etc) are doing. I just picked some points on the course, and analyzed the videos on YouTube to get rough times within a second. (I could have loaded the videos up in a video editor and gotten more accurate times)

Here's what I came up with for elapsed time per segment:

LW-PP-Segment
0 - 0 - Timer
7 - 6 - First Slalom Cone
10- 9 - Left Apex
4 - 4 - End of Wall
6 - 7 - Exit Apex
7 - 6 - Entry of In&Out
4 - 5 - Last Left Apex
5 - 4 - Final Gate
2 - 2 - Finish
45-43 - Total Time

Time to break out the video editor...

https://youtu.be/gjcqvP5SjWc

All numbers are frames, 30 frames equals 1 second.

+24 -Timmers to slalom : Biggest gain for me.
+18 - slalom : My only other real "gain".
https://youtu.be/7p1cb5s31PY
-3 - Turnaround : Might even be a tie.
https://youtu.be/hRtUeLKrVhk
+7 - The rest : Again, within the noise.
https://youtu.be/UDXmwqkdXBk
46 - total frame victory for Hiroshima over Laem Chabang.

Basically I'm faster in a straight line and a slalom. About the same everywhere else. Never considered my car's strengths to be acceleration or quick transitions.

Your car accelerates quicker than my Mirage. YOU slalom faster than I do.

Oh, and simple math: frames x .033 = approximate seconds.

Hi guys! I wanna start by saying this has been a great experience and will continue to participate in this great atmosphere with good people.

After having a tough morning session, I manage to drop 2.16s from my best morning run thanks to Matt for giving me pointers and showing me what my car can do.

Heres a vid of my best run of the day not as fast as most of you but will get there with patience and practice.
https://youtu.be/XWwXJTgM4Ms

Jorge, 39th out of 87 drivers on your third event is actually not bad at all! You're in a tough class, but you'll get there.

Philip looked so smooth out there, awesome drive bud.

Rpwolf wrote:Philip looked so smooth out there, awesome drive bud.

Wheres the video of your run!

QLITV wrote: Heres a vid of my best run of the day not as fast as most of you but will get there with patience and practice.

Your slaloms def had a better line than mine, good stuff