Points #2

Cash Davidson · **Posted:** Mon Mar 04, 2013 7:53 pm

JamesShort wrote:

So running tally of spins on first run:

Gwen
Matt McGrain
James Short

Who else?

I don't think Jeremy or Robert Plank spun....amazing!

I apparently over-achieved by spinning on my first AND second runs - and fourth. I'm gonna go back to a softer rear swaybar.

On another note, I think the my co-driver (who did very well for a novice) will be back for event#3 in his own car - a 351-powered '70 Mustang. :thumbsup:

JamesShort · **Posted:** Mon Mar 04, 2013 8:43 pm

Cash Davidson wrote:

I apparently over-achieved by spinning on my first AND second runs - and fourth. I'm gonna go back to a softer rear swaybar.

Like

Quote:

On another note, I think the my co-driver (who did very well for a novice) will be back for event#3 in his own car - a 351-powered '70 Mustang. :thumbsup:

Like!

Zach Hill · **Posted:** Mon Mar 04, 2013 11:18 pm

Carlton and I were able to reconstruct the results by massaging AXware log files and recover them into a new event file! No runs had to be manually entered, they were all there. We did a final audit with the printed and raw sheets, so they should be accurate.

Results!

Steven Carter · **Posted:** Tue Mar 05, 2013 3:02 am

You guys rock! Thanks for the overtime effort to recover data. :thumbsup:

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

Scott Johnson wrote:

BriceJohnson wrote:

Scott Johnson went agricultural, I'm guessing there was a spin involved in that. . .

Hey now, a spin would be 360 degrees. I underachieved, I only went about 180. That means I turned, and drove into the grass backwards. At some point soon, I'll post the in-car to prove my point.

I didn't see your off, sorry. I was just guessing by the fact that your Star Specs looked more like BFG all terrains back in pit.

Steven Carter · **Posted:** Tue Mar 05, 2013 10:07 am

Kraig Klippel wrote:

My gut says they have about the same Longitudinal grip. I don't want to say they have more or less being first day on them and they have not been scrubbed in, those run were the scrub in period. I do think they have more Lateral grip, but unfortunately my last couple of runs did not show up on the data logger. (This is not the first time where run are deleted from solostorm) There was more inside wheel spin with the rivals, which I think are due to the tread pattern, and the more body lean due to more lateral grip. My initial thought is up the spring rate to counter the increased grip.

As for feel, they act like the Toyo, in that they like slip angle. (or my car likes slip angle as well as my driving style) They felt like toyo with more grip. In contrast, the Z2 had amazing turn in. I'm not used to that and don't like it. I was all over the place on timing with the Z2, hitting turn in cones left and right. With the Rival, they complement my style of turning early to get the car sliding around cones. People have said that the Z2 have a fast, peaky grip, I would agree. As for the Rivals, they have a wider grip sweat spot that takes just a bit more time to get there, meaning less initial response than the Z2. This isn't a bad thing if you like this characteristic.

To be fair, the Z2 take scrubbing in and runs to become fast, so they may be just as fast as the Rival. After yesterday, I'm going with Rival due to Contingency, driving style, and wear.

My only wish is that the tread pattern was the R1R's, then they would have more Longitudinal grip and thus less inside wheel spin.

Thanks for the feedback! At the end of your run I think you said 25--as in 25psi? If so, that's pretty close to R1R pressures for an STS Miata, right? Were you at that pressure because it was cold, or is the sidewall stiff enough to support that pressure on a car of your weight?

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

I just realized that I left my fine malt beverage on the bus, hoepfully its still there. I hope James isn't offended that I forgot such a thoughtful gift before leaving early.

JamesShort · **Posted:** Tue Mar 05, 2013 11:03 am

BriceJohnson wrote:

I just realized that I left my fine malt beverage on the bus, hoepfully its still there. I hope James isn't offended that I forgot such a thoughtful gift before leaving early.

I gave the Grape one to Aaaron Delong....and he drank it...

Jeremy Ellison · **Joined:** Fri May 13, 2011 5:01 pm **Posts:** 186

Great event. Thanks to everyone who helped pull it off. I really enjoyed the course. It was challenging but flowed well.

Here's the side-by-side of James's and my best runs:
https://www.youtube.com/watch?v=RLgS4oRllGI

James and I did a bit of data logging. It's something I want to get more serious about. Here's the graph of our speed (as reported by the ECU, in KPH) side by side. Blue is me, green is James. Anyway, I thought it was interesting. If any veteran data loggers out there have any tips, I'm all ears.

http://i.imgur.com/Ej8A9sg.png

Zach Hill · **Posted:** Tue Mar 05, 2013 2:32 pm

Jeremy Ellison wrote:

Here's the side-by-side of James's and my best runs:
https://www.youtube.com/watch?v=RLgS4oRllGI

Nice. Looked like you were slightly ahead until the last sector.

Jeremy Ellison wrote:

James and I did a bit of data logging. It's something I want to get more serious about. Here's the graph of our speed (as reported by the ECU, in KPH) side by side. Blue is me, green is James. Anyway, I thought it was interesting. If any veteran data loggers out there have any tips, I'm all ears.

http://i.imgur.com/Ej8A9sg.png

What are you using to record? Hondata? Looks like quite granular data, awesome. I wish my AP1 ECU reported at more than about 0.5 Hz.

Jeremy Ellison · **Joined:** Fri May 13, 2011 5:01 pm **Posts:** 186

I used Noah's bluetooth ODB2 reader (I have since ordered one of my own) with the ALapTimer app. I couldn't find my 10HZ GPS, or I would've tried to overlay GPS speed along with ECU speed.

I'm still kind of surprised that the AP1 ECU doesn't report more often. Have you verified the same result on other AP1 S2000s?

And yes, James smoked me in the sweepers at the end. The video shows it and the data confirms it.

Steven Carter · **Posted:** Tue Mar 05, 2013 2:48 pm

As far as the speed tracing, it's hard to get a lot of useful info from it. Sure you can say you faster in this segment vs James' faster speed in a different segment, but if you took a longer distance to go faster that may not be worth the higher speed. (edit: after putting the data image next to the video, James had a tighter line and a higher speed through the finishing sweepers. Basically, you wimped out at the end :wink:

)

IMO, you should download racerender. If that datafile can be exported as a .csv file you can then import it into RaceRender and superimpose it on your video feed. I'm pretty sure all Hondata is exportable in *.csv. ( As an aside, I currently use a PLX Kiwi Wifi, probably the iOS version of your BT reader, which gives a fair number of datastreams to sample, but the more you look at the slower the sampling rate. I get ~8hz tracking speed, rpm and throttle position. I would like to get some braking info--does Hondata have access to brake position data? )

Then you'll be able to see where you are going faster, what line you are taking at that speed, and what driver got through which segment of the course quicker. I log my throttle position, tach and vehicle speed and transpose it against my video. I do the same for my co-driver, then run them side by side. The video loses a little resolution by being double-processed, but I'm only using the free version. IIRC the paid version does a better job preserving video quality as well as gives more flexibility with visual presentation.

Jeremy Ellison · **Joined:** Fri May 13, 2011 5:01 pm **Posts:** 186

Yeah, I need to move the data over to my windows box to use Race Render...

I have all the data. GoPro video, Phone video, ODB2 log, accelerometer log, and GPS log. Just need to figure out how to use it.

I think the speed alone chart does provide some insight. For instance, I launched too hard and shifted too slow. I entered the slalom faster, but James accelerated through it more and exited faster. That said, point taken. It is important to combine the speed data with the location data. The time is actually out there, and it's cool to see where at least some of it is (or was).

noahfleming · **Posted:** Tue Mar 05, 2013 3:01 pm

Here is my second fastest run

http://www.youtube.com/watch?v=RmXemu55OAw

Zach Hill · **Posted:** Tue Mar 05, 2013 3:05 pm

Jeremy Ellison wrote:

I'm still kind of surprised that the AP1 ECU doesn't report more often. Have you verified the same result on other AP1 S2000s?

I haven't tested another AP1, but Noah's RX-8 with the exact same Bluetooth adapter and phone reported VERY fast and smooth. Just finally got around to doing some research, and here's a thread that confirms a max of 3 Hz @ 2 sensors logged:
http://www.s2ki.com/s2000/topic/904853- ... __21300420

I wonder if I could get 6 Hz with only one parameter logged? Really, I just want throttle position. Speed can be calculated from 10 Hz GPS, and acceleration data from the phone. More testing is needed...

...and at the end of the day, I'll take +1,000 RPMs over fast data logging. :mrgreen:

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