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post #1 of 19 (permalink) Old 12-29-2009, 03:00 AM Thread Starter
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crossweight percentage

whats a good crossweight percentage and how do you find the percentage?
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post #2 of 19 (permalink) Old 12-29-2009, 10:41 AM
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Quote:
Originally Posted by 67-4-fun View Post
whats a good crossweight percentage and how do you find the percentage?
To find the CW%, you need to weigh each corner of the car.
Add your LR weight and your RF weight together, and divide that
by your total weight.

There really is no "what's the best" answer.
Each driver likes different feels to their cars, and each track may
have different characteristics.
If you start at 50% and adjust each way from there, you will find
what works best for you.
But of course, asking some of your local hotdogs what they run,
is not a bad place to start either.

But at 50% CW, if your car doesn't want to turn very well,
try DEcreasing the CW. If the car just seems way too loose,
try INcreasing the CW.

Hope that is what you were looking for.
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post #3 of 19 (permalink) Old 12-29-2009, 12:00 PM Thread Starter
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yes thank you, I did find a crossweight caculator, Here is what i have at the moment, what your thoughts

totall weight -34.7
totall left side - 21.6
left side % - 62
rear totall% -55
diagonal % - 46

Last edited by 67-4-fun; 12-29-2009 at 12:16 PM.
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post #4 of 19 (permalink) Old 12-29-2009, 12:54 PM
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Originally Posted by 67-4-fun View Post
yes thank you, I did find a crossweight caculator, Here is what i have at the moment, what your thoughts

totall weight -34.7
totall left side - 21.6
left side % - 62
rear totall% -55
diagonal % - 46
Like I said before, it's tough for someone to say "this" is what you should run.
For instance, on a 135' carpet track, I ran considerably more CW
than you are running... closer to 51%.
But that doesn't mean a whole lot if you are running something entirely
different.
Plus... I have seen really fast guys battle lap after lap with one guy
with 48 and the other with 52.

Your 'location' says at the velo.
I wouldn't have a clue on that.
But my comments would still hold true.
Cross weight isn't an absolute.
It's a reference.
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post #5 of 19 (permalink) Old 12-29-2009, 01:40 PM Thread Starter
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thanks for your insight... i was just curious of what some opinons were on this subject... as for being at the velo during the summer only, i just have not changed it on my location id..
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post #6 of 19 (permalink) Old 12-29-2009, 05:09 PM
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Only "rule of thumb" that I've noticed that works consistently is to have about 100grams on the RF in a 1cell car. This is without the body, for flat carpet tracks, class/brand don't seem to matter. The LF and LR weight will vary GREATLY depending on setup, brand, etc....but some really good cars I've had the chance to scale always were in this neighborhood.
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post #7 of 19 (permalink) Old 12-29-2009, 06:19 PM
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Originally Posted by Kevin Koback View Post
Only "rule of thumb" that I've noticed that works consistently is to have about 100grams on the RF in a 1cell car.
This is why I hate to suggest a particular number, as opposed to
a percentage...
We don't know if his total weight was with body or without, if it was without,
his car is heavier than Kevin's, I'd bet.

If you do the calculations using 67's 34.7 oz. weight, for his RF to be 111 g,
his LF would have to be ~330, and both rears would be ~275....
That ain't gonna work.

Personally, it appears that one, or more of your corner weights, 67, are not
accurate. OR the calculation was off.
When I use your 34.7 total, and your side/rear percentages, I come up with
around 51% cross weight. Not 46%.
34.7oz x .0352 = 985g

985 x .62 x .45 = 274 985 x .38 x .45 = 168

985 x .62 x .55 = 335 985 x .38 x .55 = 205

335 + 168 = 503

503 / 985 = .51

So make sure that there are no binds in the front or rear,
and weigh your car again.
then move your scales around a time or two, and see if your results
are similar.
They probly will not be exact, but they should be close.
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post #8 of 19 (permalink) Old 12-29-2009, 06:35 PM Thread Starter
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it maybe a little heavy on the lr, the lr is about 1/2 -3/4 oz heavier than lf
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post #9 of 19 (permalink) Old 12-29-2009, 06:38 PM Thread Starter
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here is the calculator that i used, its on the left colum and click on split/wedge http://www.pdxracing.sytes.net/
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post #10 of 19 (permalink) Old 12-29-2009, 09:25 PM
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If you happen to own an Iphone there's a handy app for calculating weights and percentages does ozs and grams, just search Cross Weight in Apps.

I,ve found that weights and percentages are handy for getting Your car back to a known baseline after repairs/Ill advised set up changes. Comparing tire weights and percentages to others cars usually just confuses the issue.
After saying that almost every type of oval car I,ve ever ran I start out here:

56-60% left side weight
53-58% rear weight
50-52% left rear to right front ( diagonal )
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post #11 of 19 (permalink) Old 12-29-2009, 10:24 PM
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Quote:
Originally Posted by Fl Flash View Post
If you happen to own an Iphone there's a handy app for calculating weights and percentages does ozs and grams, just search Cross Weight in Apps.

I,ve found that weights and percentages are handy for getting Your car back to a known baseline after repairs/Ill advised set up changes. Comparing tire weights and percentages to others cars usually just confuses the issue.
After saying that almost every type of oval car I,ve ever ran I start out here:

56-60% left side weight
53-58% rear weight
50-52% left rear to right front ( diagonal )
This is correct for a banked track.

Flat track I found this to be true.

60%-64% left side weight%
43-55% rear weight%
40-47% Cross-weight%
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post #12 of 19 (permalink) Old 12-29-2009, 10:36 PM Thread Starter
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This is correct for a banked track.

Flat track I found this to be true.

60%-64% left side weight%
43-55% rear weight%
40-47% Cross-weight%
acording to what you have here, i am right in the ball park if the calculation of mine are correct from the calculator that i used... All of this was a curiosity of mine, i really dont set a car up using these formulas but i was curious as to what mine are and how they compair to others.
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post #13 of 19 (permalink) Old 12-29-2009, 11:09 PM
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Quote:
Originally Posted by RPM View Post
This is correct for a banked track.

Flat track I found this to be true.

60%-64% left side weight%
43-55% rear weight%
40-47% Cross-weight%
LOL, give me banking and some cap tires and I,m a happy racer
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post #14 of 19 (permalink) Old 12-29-2009, 11:17 PM
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Meeeeeeeeee toooooooooooo! I am not even in Left field yet with the whole carpet thang! When is spring coming????
Interesing thread though. Maybe I can learn something. I'm taking notes anywho.
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post #15 of 19 (permalink) Old 12-30-2009, 06:32 PM
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LOL, give me banking and some cap tires and I,m a happy racer
Amen Brother-Where has all the banked tracks gotten gone to?. I want to move there.
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