Gravity Racer, part IV

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Another amazing job…. It looks very aerodynamically slick! I will be surprised if it doesn’t win the competition…
 

Chris Kouba

Supporter
Chris, how about adding "Moon discs" over the wire spoke front wheels? They should reduce drag a bit.
How do these look Neil:



Made of duct tape and manilla folder card stock (not from the moon...).

The three complete ones will go back on the car for testing on Fri. Swapped out the bearings for some smoother ones as well. Looking forward to seeing the results.
 

Neil

Supporter
How do these look Neil:



Made of duct tape and manilla folder card stock (not from the moon...).

The three complete ones will go back on the car for testing on Fri. Swapped out the bearings for some smoother ones as well. Looking forward to seeing the results.
Amazingly transparent, Chris. :rolleyes:
 

Chris Kouba

Supporter
So we tested today.

Bill and I were chatting on the way home from the prior session about what it'd take to break the 55 mph mark. Based on what we had been doing, I wasn't sure this would reliably be in the cards, but I reeled off the list of things I thought we needed to do:

  • Spoke covers
  • Wheel well closeouts (side and bottom)
  • Finish the rear lower paneling
  • Close out and tape up the canopy/gaps
  • Tape up all the seams
  • ...and probably a few other things which I can't think of.

I went through the list this week and knocked out all the items I could think of. The configuration we had when we unloaded from the van today was our "all-in" set up- it was our best foot forward and I'm not sure I had any more tricks up my sleeve. We walked the course again and swept it clean where needed, refreshed myself on the best place to position the car through the various bumps, and prepped the car. Once it was set, we towed it up to the start, pointed it back down the hill, and let it roll.

It felt OK, but it also felt like it wallowed or floated around a bit. I wasn't nervous about it but it was something that I thought I might look into. As I shut it down, I honestly wasn't sure if it was a fast run or not. The car just went where I put it and felt pretty good. I clambered out and checked.

What?!!?!??

58.9 MPH

Uh... Wow!

After a bit of discussion with Bill, I wasn't sure there was anything I wanted to change, and as I said earlier, I had no further tricks up my sleeve, so no upgrades in the truck to bring out. So the only thing left to do was go repeat it. So we did. This time, I worked a bit more of the optimal line, based on our experiences there before. The wallowy feeling disappeared. The car felt super-steady. Checking the GPS at the bottom was shocking.

60.3 MPH

I think we're good.

My souvenir for the day:


Another fantastic day!


 
Last edited:

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Fantastic!!! This year’s competition had better have stepped up their game or they’ll all be racing for second place!
 

Glenn M

Supporter
That worked, I can see those now.
That's an amazing speed Chris, and the racer looks fantastic!
Good luck in the race.
 

Kevin L

Supporter
So we tested today.

Bill and I were chatting on the way home from the prior session about what it'd take to break the 55 mph mark. Based on what we had been doing, I wasn't sure this would reliably be in the cards, but I reeled off the list of things I thought we needed to do:

  • Spoke covers
  • Wheel well closeouts (side and bottom)
  • Finish the rear lower paneling
  • Close out and tape up the canopy/gaps
  • Tape up all the seams
  • ...and probably a few other things which I can't think of.

I went through the list this week and knocked out all the items I could think of. The configuration we had when we unloaded from the van today was our "all-in" set up- it was our best foot forward and I'm not sure I had any more tricks up my sleeve. We walked the course and swept it clean where needed, refreshed myself on the best place to position the car through the various bumps, and prepped the car. All set there, we towed to the start and launched.

It felt OK, but it also felt like it wallowed or floated around a bit. I wasn't nervous about it but it was something that I thought I might look into. As I shut it down, I honestly wasn't sure if it was a fast run or not. The car just went where I put it and felt pretty good. I clambered out and checked.

What?!!?!??

58.9 MPH

Uh... Wow!

After a bit of discussion with Bill, I wasn't sure there was anything I wanted to change, and as I said earlier, I had no further tricks up my sleeve, so no upgrades in the truck to bring out. So the only thing left to do was go repeat it. So we did. This time, I worked a bit more of the optimal line, based on our experiences there before. The wallowy feeling disappeared. The car felt super-steady. Checking the GPS at the bottom was shocking.

60.3 MPH

I think we're good.

My souvenir for the day:


Another fantastic day!


Well done! That is fantastic
 
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