Wannabe rookie needs help with wheel/car prep for June!

[Guest]

Hey in the quest for speed, leave no stone unturned, or in this case leave no lube unused

Quote:
Really Sondo????

Just messing with you. I am still laughing!!

 

[bracketracer]

I've even tried personal lubricants.

Well, at least the leftovers will be fun to use up unlike all those other lubes!

 

[Crash Enburn]

I've even tried personal lubricants.

At the end of each run, his cars ask for a smoke.

 

[Rocket car]

I've even tried personal lubricants.

So Rocket which did you use .. His or Hers or both ... Maybe that is why you were RED HOT on Zeebs track????

Papa V

A gentleman never tells.....

 

[IAE Racing]

Looks like a better plan than doing 7 loads of laundry.

 

[bracketracer]

I had a question about car construction. If the wheel/axle alignment is so critical, does it follow that the chassis needs to be stiff as well? Chassis flex could possibly affect wheel alignment, couldn't it? Or is it not enough to worry about? Seems like the lighter I go the more bendy they get. Do I just need to pay attention to the rear axle beam stiffness to keep the rears aligned?

 

[Rocket car]

I had a question about car construction. If the wheel/axle alignment is so critical, does it follow that the chassis needs to be stiff as well? Chassis flex could possibly affect wheel alignment, couldn't it? Or is it not enough to worry about? Seems like the lighter I go the more bendy they get. Do I just need to pay attention to the rear axle beam stiffness to keep the rears aligned?

Look under "building tips"--hollowed out cavity. That should help.

 

[GravityX]

Created link.

Look under "building tips"--hollowed out cavity. That should help.

I had a question about car construction. If the wheel/axle alignment is so critical, does it follow that the chassis needs to be stiff as well? Chassis flex could possibly affect wheel alignment, couldn't it? Or is it not enough to worry about? Seems like the lighter I go the more bendy they get. Do I just need to pay attention to the rear axle beam stiffness to keep the rears aligned?

 

[bracketracer]

Thanks for the link!
Hmm. I don't think I'll have time to incorporate all those ideas in a car and have it done by the June deadline. I'll send whatever's done to get a baseline.

On a car with a super thin front, do you not raise the NDFW very much or not at all? That car named Flapjack didn't look much thicker than the front axle diameter in the photo!

I had been drilling the NDFW hole at the same angle as the rears and raising it .050". With the bent axle on the right I might have the NDFW much higher than it needs to be?

 

[E.T.Racing]

The bend of the DFW axle will naturally lift the NDFW.

 

[pony express]

The flex is still up to debate. Once last year I experimented with a car that had a "independent" rear axles. I drilled the holes then cut the body right down the middle in the back. I cut far enough forward to be sure everything was independent. The result was no faster and no slower. When I taped the rearend back together the times slowed probably due to misalignment.

 

[bracketracer]

Well, I finished building the body yesterday. Took it out of the clamps and weighed it along with a set of Cheetahs and 92X's. 139 grams. But that's without paint. Looks like I'll be painting it on the scale so I know when to quit! So if you see it at the June race half painted you'll know what happened!

 

[bracketracer]

I ran the new car this morning using stock BSA wheels and axles following DD4H's prep formula and using oil. Picked up about .030 sec. on the average. Is that about normal for switching from graphite to oil? I'm holding off on prepping the Cheetahs while I practice on the cheap wheels!

Also, when I look at the 92x's under a microscope the surface appears to have tiny annular grooves cut into it. When I go to prep the axles should I try to polish those out or polish the surface and leave the rings? The stock axles shine like chrome under the scope but I wonder if these tiny rings wouldn't also cut some drag? Do they help retain the oil or something or are they just machining marks and need to go away?

 

[GravityX]

Those are machining marks on the 92x axles, just follow the polishing process as outlined in the Oil Secrets DVD and you'll be fine.

 

[bracketracer]

Cool! Thanks!

 

[derby freak]

I always tell people that are just starting in pro pwd to refer to the "going sub 3.0 by w racing" topic of the message board. If you follow the instructions in the post it will help you to build your fundamentals and you can adjust what works for you the best from there. First you must start with the basics. Im glad to see you are changing to oil once you use it you will never use graphite again.

 

[derby freak]

whatever lube you use always use johns method of applying it. i have found no method so far that works better.

 

[bracketracer]

I always tell people that are just starting in pro pwd to refer to the "going sub 3.0 by w racing" topic of the message board. If you follow the instructions in the post it will help you to build your fundamentals and you can adjust what works for you the best from there. First you must start with the basics. Im glad to see you are changing to oil once you use it you will never use graphite again.

I did read that post before I started building. My first car was based on that, then i started tweeking. I added a little more cant to the rears on this one to see what it did. I'm at 3.5 now. I not sure if I have the COM too far back now? It's at 9/16. 12+12 packed tight to the rear axle. I started with the steer at 4" in 4', it took 4" in 41" to get a consistent straight pass. I really just want to get a time on a NPWDRL track so I have something to compare to my track. Anybody know how Zeeb's track compares to John's? We're using Zeeb's track for the June race, right?

And I'll still be using graphite. I have a Cub Scout and that's all they let us use!

I think I understand the wheel prep a little better now, so I'm going to prep the Cheetahs and make some runs with my fingers crossed. Even if the Cheetahs pick it up .050 or so, I still think it needs to be faster. It ran 2.772 on Thursday (32' actual) on stock kit wheels and nails. A 42' track is almost 5' longer than mine so I'm thinking I have a ways to go.

 

[Rocket car]

I test on Zeebs track it is a close to John's as possible. I ran 2.975s on zeebs track, then sent the car to John's and ran the exact same time to the thousands.

Ps.each section of track adds about .37 seconds. 7ft sections.

 

[bracketracer]

Cool! Thanks Rocket! That's good to know that both tracks are similar in time. It's a pretty rough way to estimate it, but if I take your .37 sec per 7ft number, divide to get the /ft time=.052 times 4.8ft (the difference between my track and the 42 footer) = .253 plus my time of 2.772 = 3.025 seconds on stock wheels. Pretty rough estmate. So with the Cheetahs I should make sub-3. Maybe.

Any chance somebody has an estimate on how much a car might pick up going from a wooden track to an aluminum track?