On board sprint car videos

[racrguy]

I have a couple of videos shot from on/inside the race car. The first one is from a practice session at Heart O Texas Speedway on a super slick track, the second is from the B main at Boyd Raceway. I had to run the B because I didn't transfer from my heat, the track was too fast, I started 6th and finished 5th in the heat, started on the pole and finished 2nd in the B due to catching a rut bad and biking the car.

Practice at Heart o Texas, camera mounted to the top of my helmet.




B main at Boyd Raceway, camera pointed at the left rear. Next time I'll run a shorter left rear now that I know how much that particular one grows.



I also have a build thread going, but not finished here:

http://www.dfwmustangs.net/forums/showthread.php?t=48466

[Ratt]

Wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee!

[SSsierra90]

Looks fun as hell. Got a couple buddies that race the ones with the 4 cylinders. One of the just started racing the big ones like yours.

[WesB]

SSSSSLLLLLLLLLLLLOOOOOOOOOWWWWW! Missing about 400 hp jk. Miss all the 305 group.

[racrguy]

SSSSSLLLLLLLLLLLLOOOOOOOOOWWWWW! Missing about 400 hp jk. Miss all the 305 group.

We can't all be a hot shit USAC driver. Lol

You're always welcome in my pits, brang y'ass!

[2011GT]

That look like fun! Are those just a single speed trans?

[jw33]

I think they are like direct drive right off the crank or some crazy shit. Cool videos.

[Mach1]

awesome!!!

[YALE]

I think they are like direct drive right off the crank or some crazy shit. Cool videos.

They're just a torque tube to a quick-change rear.

[WesB]

The front yolk for the driveshaft bolts to the crank, the driveshaft runs through a torque tube, and slides into the snout of the rearend. The driveshaft is not bolted on either end. The rear end has and in/out box that engages and disengages the rearend.

[racrguy]

That look like fun! Are those just a single speed trans?

Nope, no trans

I think they are like direct drive right off the crank or some crazy shit. Cool videos.

Mostly correct

They're just a torque tube to a quick-change rear.

Partially correct

The front yolk for the driveshaft bolts to the crank, the driveshaft runs through a torque tube, and slides into the snout of the rearend. The driveshaft is not bolted on either end. The rear end has and in/out box that engages and disengages the rearend.

All the way correct.

[cool cat]

The left rear tire looks like it wiggles a lot when you are not on the throttle, is that all sidewall flex I'm seeing?

[ktm300hater]

The left rear tire looks like it wiggles a lot when you are not on the throttle, is that all sidewall flex I'm seeing?

Race tires move a lot. You have forces from acceleration, deceleration, bumps in track and side loads from pitching it in the corner.

[ktm300hater]

Oh, and it looks slow. I want to drive it

[racrguy]

The left rear tire looks like it wiggles a lot when you are not on the throttle, is that all sidewall flex I'm seeing?

Yes, that's sidewall flex. What's happening is I'm having to drive the car through the set to get it to turn, the left rear I had on the car is growing far more than I expected it to and tightening the car up, so I've got to throw the car sideways. The flex you see is from the LR tire gaining and losing traction. To put things into perspective, that tire (labeled as a 96) had a circumference of 92.5@ 4 lbs of air pressure at rest, the same size as my tire that's labeled as a 92. You can see how much it grew. I will not be making that same mistake again.