CG data and questions

[PWD_addict]

At our Pack Derby, son's CM was 1 1/8" and he won. At Godson's Derby, CM was 3/4"--wiggly but BAD FAST--alignment wasn't great. I ran my son's car at Godson's but modified CM to 13/16", with very good alignment, it was VERY fast with no wiggling. Both tracks are smooth--Godsons' a little more so at the transitions (wooden but smooth). Our Pack aluminum one has so-so transitions.

Bottom line is that I suspect your CG at 1.44" is conservative. Especially if you can do a decent alignment.

[doct1010]

PWD, thats from BACK of car not rear axle.

[Go Bubba Go]

Side rails are about 3/4" to 1" tall. Will rub full sidewall of wheel. Letters will rub. Removal of letters is not allowed be rules. Narrowing rear track of car sounds like a good choice though.

Can you run with the wheels "inside out"? Ha ha, Ha ha (diabolical laugh - think "Renfield").

Reverse cone the body near the axles so that no contact is made between the sidewalls (and definitely not the letters) and the car body?

Sorry, not enough time to look through the rest of the thread. Will edit later if time allows.

[BigSilver]

CM at 1.44" from back of car, Axle at .644", CM at .4" in front of rear axle.
Car seams stable but still working on paint and wheels last night. I have had good results with alignment last year and while time intensive it is well worth the work for me and my son. Really working hard this year with my son in order to tie good results to hard work and dedication. Electronic thumb toys are taking a tole on my sons attention to homework and real adventure.

Stan,
Axle head strike first would likely be desirable but track side wall height estimate last night was wrong. Rail height is about 1/2 inch so letters will scrub unless I try whiskers or Warthog's method. Car is built so Son may not go for it. He wants a 'cool' paint job more than a fast car. That is his choice. My daughter however wants to go fast so the open class car is where we can play with other options as long as it is a pink car with blue flames.

[BigSilver]

Go Bubba Go
Reversed wheels has a great deal of merit! That is a concept I can sell.
Thanks!

[Go Bubba Go]

Go Bubba Go
Reversed wheels has a great deal of merit! That is a concept I can sell.
Thanks!

Let us know if it works. Even if it's on a pretty pink car with blue flames!!!

[PWD_addict]

PWD, thats from BACK of car not rear axle.

In that case, that seems quite aggressive! I'd like to change my vote.
Of course, I'm a newbie and I thought 0.75" in front of rear axles was pushing the edge . . .

[BigSilver]

Teeman,
Thought about it, drew up some plans, haven't had time. In last month and a half we have held three builders workshops, had our B&G, built an HO scale diorama of a Sequoia logging camp with son, made a caricature in a can for daughter, attended pre camporee overnighter. 4th coat of kills went on car last night, son lathed 4 sets of wheels and impound is tomorrow at 1:00 with first season b-ball game at 11:00. Send me a PM with a photo? Life is Good.

[Go Bubba Go]

Go Bubba Go
Reversed wheels has a great deal of merit! That is a concept I can sell.
Thanks!

Let us know if it works. Even if it's on a pretty pink car with blue flames!!!

An afterthought:

The advantage of "inside out" is really only gained for those wheels that will touch the rail.

Given that it will be a bit tedious to "cone" the body at the axle location, perhaps only 2 (maybe 1) of the wheels should be inverted? If designed correctly, only 2 (maybe 1) should ever touch the rail

A little less work, and a little more fun watching the other builders trying to figure out why you did what you did, especially with only 2 (or 1) wheels...

[BigSilver]

Thanks for the follow up. I had already concluded that single front wheel was all that was required if inverse rail riding is set up correctly. This will be fun to see if both my children are willing to do something unorthodox not to mention the hoots and howls at impound.

[Go Bubba Go]

Thanks for the follow up. I had already concluded that single front wheel was all that was required if inverse rail riding is set up correctly. This will be fun to see if both my children are willing to do something unorthodox not to mention the hoots and howls at impound.

It probably reveals some deep-seated personality flaw, but I do get a kick out of watching folks snicker and sniff at the unorthodox, only to end up on the "slow end" of the results.

What is that old saying?... dumb like a fox

[BigSilver]

OK, the update post race.
Son won Den first place, advanced to Grand Championship round and placed first in all but one race. Took First place overall.
Car ran with conventional wheel installation.
track was rougher than I remembered but we set the car up to rail ride outside and had 1" in 36" bias to the contacting front wheel. Performance was great through out the pack races. Daughters car was smoking fast. daughter did not want to run inside out front wheel so we set it up to rail ride like my sons. Sons CG was at 1.44" from back of car, daughters CG was at 1.28" with close to same alignment. Her car would finish about a car length ahead of my sons. Since she raced in open class we used light wheels and speed axles. Not the most expensive available but much lighter than stock. A couple of my sons den members began a little ribbing since he was skunked by a pink car. He told them that they could race her at their own risk....

[Go Bubba Go]

A couple of my sons den members began a little ribbing since he was skunked by a pink car. He told them that they could race her at their own risk....

LOL. Thanks for sharing the outcome, sounds like it was a lot of fun.