Gravity Racer, part IV
- Thread starter ckouba
- Start date
Chris Kouba
Supporter
Got a call from the derby media guy last night, apparently he had been trying to get ahold of me for a while with the wrong number. Could I meet him with the car at a news room at 0400 this morning (~9h from when he called)? I was in the process of picking up the graphics, and then had to pick my dad up at the airport, then apply the graphics, then drop the car off, then go back to get some sleep (2h), then show up at 0430 for the broadcast which started at 0500. No prob.
Hey dad, want to join me?
Heck yeah!
In the lobby when I dropped it off:
In the newsroom;
On air with the anchor in my car and derby PR guy in the other (image sent by a friend who was up and watching the program!!):
After, with the derby PR guy:
Hey dad, want to join me?
Heck yeah!
In the lobby when I dropped it off:
In the newsroom;
On air with the anchor in my car and derby PR guy in the other (image sent by a friend who was up and watching the program!!):
After, with the derby PR guy:
Chris Kouba
Supporter
Some video clips:
I got comments from the production staff about how I went directly from guest of show to morning anchor all in the space of one broadcast. They were impressed!!
I got comments from the production staff about how I went directly from guest of show to morning anchor all in the space of one broadcast. They were impressed!!
Doc Watson
Lifetime Supporter
Great stuff Chris.. 60 mph... wow
Chris Kouba
Supporter
I'll take the mystery out of things, first pass- new record. Was 71.1, now 68.4 seconds.
Car is phenomenal.
Car is phenomenal.
Chris Kouba
Supporter
False alarm. Timing and scoring error. Still won the event, but best run was 71.3, so no record.
But I still won anyway, and had a great day!
But I still won anyway, and had a great day!
Isn’t that the record you owned anyway?
Regardless - Congratulations!!!
Neil
Supporter
Have you thought about replacing your wheel bearings with ones made with ceramic balls? Some Bonneville cars are using them for the ultimate in rolling resistance.
Chris Kouba
Supporter
Nope, never had the full record. It is 71.1s and prior to this year, the best time I ran was a 71.9s. The issue was that the timing table thought that the results were being reported in decimal minutes (1.14m, which is where 68.4s came from) when it was just 1m14s, or 74s- an average fast time for me. Was I disappointed? Meh, whatever.... It's a great event and I still won it again, so again, whatever...
I did move the needle a little bit for me though, dropping my personal best from 2019's 71.9 to 71.3, a cringe-worthy .2s off the course record. In all honesty, one more pass and I may have been able to squeak it out.
Oh well though, still a fantastic event. a great day, my dad had an amazing time at it, and some wonderful people. Good times!!
More pics as they show up- I didn't take too many as I was pretty busy...
I did move the needle a little bit for me though, dropping my personal best from 2019's 71.9 to 71.3, a cringe-worthy .2s off the course record. In all honesty, one more pass and I may have been able to squeak it out.
Oh well though, still a fantastic event. a great day, my dad had an amazing time at it, and some wonderful people. Good times!!
More pics as they show up- I didn't take too many as I was pretty busy...
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Thanks for the update, sounds like another great year. Congrats!
"Average fast time" is interesting considering all of the different designs you have yet but consistently similar quick speeds. Any idea what that means regarding where improvement might come from?
Chris Kouba
Supporter
They were a bunch of JPL or Lockheed Martin nerds who were killing it at the time. I have a pic somewhere and will post when I find it. I'm out paddling thru the San Juan Islands with my dad for a few days.
I come back to the fact it was ~103° on the day they set the record. My times improved all day as it got warmer. Another few degrees warmer and I would have gotten it.
But it wasn't and I didn't.
Oh well. Still a fantastic event, I still had a great time,, and it was a thrill seeing it again for the first time through my dad's eyes.
I come back to the fact it was ~103° on the day they set the record. My times improved all day as it got warmer. Another few degrees warmer and I would have gotten it.
But it wasn't and I didn't.
Oh well. Still a fantastic event, I still had a great time,, and it was a thrill seeing it again for the first time through my dad's eyes.
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Congratulations from France,
but I do notice that even going down hill cost energy
Paul
but I do notice that even going down hill cost energy
Paul
Chris Kouba
Supporter
It feels like the event took place in a vacuum this year. I didn't have many people on the hill with cameras and have found very few online so far. I stumbled across this one though, taken pretty close to the start. The car looks fantastic!
Chris Kouba
Supporter
Another appeared in my inbox:
This is up at the top of the course, speed still pretty modest. We get out of the start box doing 10-12 MPH and I had onboard GPS readings as high as 53.3 MPH over the various passes.
This is up at the top of the course, speed still pretty modest. We get out of the start box doing 10-12 MPH and I had onboard GPS readings as high as 53.3 MPH over the various passes.
Chris Kouba
Supporter
I was able to get a few pics off of my dad's phone today. Still waiting for the event's official photos to get posted but these were a pleasant memory from the summer:
![IMG_2497[1].jpg](https://www.gt40s.com/attachments/img_2497-1-jpg.127129/ "IMG_2497[1].jpg")
![IMG_2494[1].jpg](https://www.gt40s.com/attachments/img_2494-1-jpg.127127/ "IMG_2494[1].jpg")
![IMG_2495[1].jpg](https://www.gt40s.com/attachments/img_2495-1-jpg.127128/ "IMG_2495[1].jpg")
Chris Kouba
Supporter
I originally had declared myself "retired" following the last event but being so close to actually getting the record, I feel compelled to try again. These builds take an enormous amount of time and effort (which needs to be pointed at a different project right now!), so to bypass a bunch of the heavy lifting, I am going to recycle the Mk VIII for the 2023 entry.
So I won't start from scratch again this year. I think the skirt would be beneficial when trying to generate downforce, but a flat bottom is more advantageous when just trying to reduce drag. One of the things I was also thinking about is actually raising the chassis slightly to give the air more space to create its velocity gradient and theoretically reducing drag. This will impact my cornering though, and I am not sure I want to monkey with what I know is working.
My biggest loss(es) come from trying to negotiate the Learning Curve. The front end was plowing quite heavily and the speed just plummeted. This did not happen with the 20" wheels and the tires they were wearing. I think for 2023, I will be changing tires to something analogous to the 20" ones. Unfortunately the 20" vendor does not have any available in 16", so I'm starting from scratch there.
Along with tires, playing with pressures might go a long way to improve the grip. On the 20" tires (which had small, indented pyramid block for their tread), I had been running at ~66# psi and they were 2.2" wide. The 16's are slicks and only 1.35" wide, and I had them up at 105# psi as well. They may have just been skating around on the pavement due to being so pumped up. I may need to lose a little top speed to carry more energy through the corner.
I'm not sure exactly what else to do, but hope to find some aero tweaks to possibly eek out a little less drag and lower the ET. The easy add is a stronger pusher, so I might be on the hunt there too. One of the other competitors had a local college lineman do his push this year and we went head-to-head in a qualy heat. He was well out in front of me until my aero advantage was able to put him in the mirrors. I just need to borrow that guy for a run!
So I won't start from scratch again this year. I think the skirt would be beneficial when trying to generate downforce, but a flat bottom is more advantageous when just trying to reduce drag. One of the things I was also thinking about is actually raising the chassis slightly to give the air more space to create its velocity gradient and theoretically reducing drag. This will impact my cornering though, and I am not sure I want to monkey with what I know is working.
My biggest loss(es) come from trying to negotiate the Learning Curve. The front end was plowing quite heavily and the speed just plummeted. This did not happen with the 20" wheels and the tires they were wearing. I think for 2023, I will be changing tires to something analogous to the 20" ones. Unfortunately the 20" vendor does not have any available in 16", so I'm starting from scratch there.
Along with tires, playing with pressures might go a long way to improve the grip. On the 20" tires (which had small, indented pyramid block for their tread), I had been running at ~66# psi and they were 2.2" wide. The 16's are slicks and only 1.35" wide, and I had them up at 105# psi as well. They may have just been skating around on the pavement due to being so pumped up. I may need to lose a little top speed to carry more energy through the corner.
I'm not sure exactly what else to do, but hope to find some aero tweaks to possibly eek out a little less drag and lower the ET. The easy add is a stronger pusher, so I might be on the hunt there too. One of the other competitors had a local college lineman do his push this year and we went head-to-head in a qualy heat. He was well out in front of me until my aero advantage was able to put him in the mirrors. I just need to borrow that guy for a run!
