.37 oz block too light?

[The Iceman]

Or no such thing if still have a com of 3/4??

Ice

[Topspin.D]

I think you're probably fine

[Noskills]

If you car is under 0.5 oz then you should have more than 4 oz of weight in the car. If this is the case your should go for a more aggressive COM.
Noskills

[psycaz]

As long as the body has enough strength, the lighter the better. It lets you put the weight where you want it.

[The Iceman]

Thanks Guys, thats what my thought was but being my first year I thought I better check! Ya, I topped it with 1/32 of Balsa with Tightbond III and it like a rock!

If you car is under 0.5 oz then you should have more than 4 oz of weight in the car. If this is the case your should go for a more aggressive COM.
Noskills

More agressive COM? Hmmm More compact weight allows this?

Ice

[Noskills]

Ice,
More compact and farther back. If you drill your rear axels 5/8th of an inch from the back of the car you can fit 2 rows of 6 1/4 in tungsten cubes. Do the same 1/8th of an inch in front of the rear axel and your COM will likely be under 4/8th.
Noskills

[The Iceman]

Ice,
More compact and farther back. If you drill your rear axels 5/8th of an inch from the back of the car you can fit 2 rows of 6 1/4 in tungsten cubes. Do the same 1/8th of an inch in front of the rear axel and your COM will likely be under 4/8th.
Noskills

Thats what I do but I change my COM to get to to the 3/4 mark with a little weight in the front. We pushed it a little to much (1/2") on our Tigers car, it was all over the place at the end the track. (fastest in the pack but still looked like we lost a bunch of time!)

Ice

[Noskills]

Thats what I do but I change my COM to get to to the 3/4 mark with a little weight in the front. We pushed it a little to much (1/2") on our Tigers car, it was all over the place at the end the track. (fastest in the pack but still looked like we lost a bunch of time!)

Ice, are you doing an extended wheelbase? If so you can easily bring your COM to 5/8 or 4/8 (or 3/8 if you dare ). The lower the COM the more drift you need to keep it on the rail. This is more true with stock wheelbase than extended. If stock wheelbase you could drop to 5-6/8th with about 3-4 in of drift over 4 ft. Also double check you rear wheel alignment!

I make 2 stock wheelbase cars with 5/8th COM that resulted in a little wobble. My drift was 3 in over 4 ft. I plan to dial it up to 4 in over 4 ft for the next race. My extended wheelbase cars have never wobbled with the same COM and lower drift.

Noskills

[The Iceman]

Ice, are you doing an extended wheelbase? If so you can easily bring your COM to 5/8 or 4/8 (or 3/8 if you dare ). The lower the COM the more drift you need to keep it on the rail. This is more true with stock wheelbase than extended. If stock wheelbase you could drop to 5-6/8th with about 3-4 in of drift over 4 ft. Also double check you rear wheel alignment!

I make 2 stock wheelbase cars with 5/8th COM that resulted in a little wobble. My drift was 3 in over 4 ft. I plan to dial it up to 4 in over 4 ft for the next race. My extended wheelbase cars have never wobbled with the same COM and lower drift.

Noskills

Hey Noskills, yes they are extended. OK OK now its sinking in, find the sweet spot. aggressive com = fast but out of control but real it in with more drift and find the sweet spot! (Sounded like Days of Thunder! ) Thanks, now I need that test track! lol

Oh Shoot, I better check Stan's Webpage, there is probably a Calculation for this!

Ice

[davet]

Thats what I do but I change my COM to get to to the 3/4 mark with a little weight in the front. We pushed it a little to much (1/2") on our Tigers car, it was all over the place at the end the track. (fastest in the pack but still looked like we lost a bunch of time!)

Ice, are you doing an extended wheelbase? If so you can easily bring your COM to 5/8 or 4/8 (or 3/8 if you dare ). The lower the COM the more drift you need to keep it on the rail. This is more true with stock wheelbase than extended. If stock wheelbase you could drop to 5-6/8th with about 3-4 in of drift over 4 ft. Also double check you rear wheel alignment!

I make 2 stock wheelbase cars with 5/8th COM that resulted in a little wobble. My drift was 3 in over 4 ft. I plan to dial it up to 4 in over 4 ft for the next race. My extended wheelbase cars have never wobbled with the same COM and lower drift.

Noskills

This looks like the info I've been looking for. We're running 5 9/16" wheelbase (5/8" or so from each end). Right now we're at 4" of drift with 3/4" COM. How far back is safe?

[Noskills]

This looks like the info I've been looking for. We're running 5 9/16" wheelbase (5/8" or so from each end). Right now we're at 4" of drift with 3/4" COM. How far back is safe?

Davet are you talking about your current car the district winner? I would say that success speaks for itself.

If I were running an extended wheelbase car I would aim for a COM of 4-5/8th with a drift of 2-3 in over 4 feet based on my prior builds and lack of wobble with those.
Noskills

[Topspin.D]

If I were running an extended wheelbase car I would aim for a COM of 4-5/8th with a drift of 2-3 in over 4 feet based on my prior builds and lack of wobble with those.
Noskills

+1

[Stan Pope]

...

Oh Shoot, I better check Stan's Webpage, there is probably a Calculation for this!

Ice

Don't I wish! The relationship between CM and toe-in seems really complex. What it seems is that more aggressive CM requires more aggressive toe-in to tame it. If you give me a proven formula (with no woo-woo factors), I'll do an all-way comp page for it!

Definitions:
1. woo-woo factors: nonmathematical factors
2. all-way comp: when enough of any parameters are supplied, the page computes he rest.

[davet]

This looks like the info I've been looking for. We're running 5 9/16" wheelbase (5/8" or so from each end). Right now we're at 4" of drift with 3/4" COM. How far back is safe?

Davet are you talking about your current car the district winner? I would say that success speaks for itself.
If I were running an extended wheelbase car I would aim for a COM of 4-5/8th with a drift of 2-3 in over 4 feet based on my prior builds and lack of wobble with those.

Noskills

Yes Noskills, same car.
This thread is like opening up a manual for solving the weight placement/drift puzzle. I'm now second guessing plan to run front and rear fenders next year because I don't want to start figuring this out again with a shorter wheelbase.

[Noskills]

This thread is like opening up a manual for solving the weight placement/drift puzzle. I'm now second guessing plan to run front and rear fenders next year because I don't want to start figuring this out again with a shorter wheelbase

Thats why this is fun!!

Noskills