Tune Table Question

[derby freak]

I've looked for some info on adjusting steer on a tuning board but haven't had much success. I guess I was wondering if you had 2" of steer on a car in 4' would the steer be 3" at 6' and 4" at 8' or would the steer be different than what I would call logical? Also would 2" of steer at 4' with an unlimited be too aggressive as a starting point?

 

[derby freak]

I would really like to see W racing put out a steer chart like he did with the com converted to the weight on the dfw.

 

[txchemist]

You can find what you need at WWW.1728.com



Your first step is to calculate the radius of the car drift- if you had a big enough table, the car would go in a large circle.


and the radius would be 354"

then you try a bigger table (remember to use 2 times the table length)



and you get the drift of 12" on the bigger table

 

[derby freak]

thanks texchem that is a great deal more steer difference than i would have calculated for that is some very good info.

 

[GravityX]

txchemist, That is some confusingly /images/boards/smilies/confused.gif good stuff right there. It took me a few minutes to figure out what was happening, but I got it. /images/boards/smilies/biggrin.gif

 

[Minions Racing]

Hey txchemist, not a big deal but you have 48*2=92. Should that be 48*2=96? The result of going 92->184 and 96->192 is the same, though, as I guess the radius cancels out.

 

[txchemist]

OUCH!, thanks Irvin, that's what I get for messing with numbers before I do my morning SUDOKU!

such a small difference did not change the answer much, but it still changes it.

The website now has gone back to where it was

92	3
184	12.158
96	3
192	12.145

 

[Minions Racing]

Thanks txchemist. This post has really piqued my interest. Here's a chart for you, derby freak. This chart uses 8ft as a reference to calculate a radius, and then uses that radius at various table lengths to calculate what the drift would be.

	table length (in.)
	24	30	36	42	48	54	60	66	72	78	84	90	96		radius @ 96 in
	0.06	0.10	0.14	0.19	0.25	0.32	0.39	0.47	0.56	0.66	0.77	0.88	1.00		4608.50
	0.12	0.20	0.28	0.38	0.50	0.63	0.78	0.95	1.12	1.32	1.53	1.76	2.00		2305.00
	0.19	0.29	0.42	0.57	0.75	0.95	1.17	1.42	1.69	1.98	2.30	2.64	3.00		1537.50
	0.25	0.39	0.56	0.76	1.00	1.26	1.56	1.89	2.25	2.64	3.06	3.51	4.00		1154.00
	0.31	0.49	0.70	0.95	1.25	1.58	1.95	2.36	2.81	3.30	3.83	4.39	5.00		924.10
	0.37	0.58	0.84	1.14	1.50	1.89	2.34	2.83	3.37	3.96	4.59	5.27	6.00		771.00
drift (in.)	0.44	0.68	0.98	1.33	1.74	2.21	2.73	3.30	3.93	4.61	5.35	6.15	7.00		661.79
	0.50	0.78	1.12	1.52	1.99	2.52	3.11	3.77	4.49	5.27	6.11	7.03	8.00		580.00
	0.56	0.87	1.26	1.71	2.24	2.83	3.50	4.23	5.04	5.92	6.88	7.90	9.00		516.50
	0.62	0.97	1.39	1.90	2.48	3.14	3.88	4.70	5.60	6.58	7.64	8.78	10.00		465.80
	0.68	1.06	1.53	2.08	2.72	3.45	4.26	5.16	6.15	7.23	8.40	9.65	11.00		424.41
	0.74	1.16	1.67	2.27	2.97	3.76	4.64	5.63	6.70	7.88	9.15	10.53	12.00		390.00
	0.80	1.25	1.80	2.45	3.21	4.06	5.02	6.09	7.25	8.53	9.91	11.40	13.00		360.96
	0.86	1.34	1.93	2.63	3.44	4.37	5.40	6.54	7.80	9.17	10.66	12.27	14.00		336.14
	0.92	1.43	2.07	2.82	3.68	4.67	5.77	7.00	8.35	9.82	11.42	13.14	15.00		314.70
	0.97	1.52	2.20	2.99	3.92	4.97	6.14	7.45	8.89	10.46	12.17	14.01	16.00		296.00
	1.03	1.61	2.33	3.17	4.15	5.26	6.51	7.90	9.43	11.10	12.92	14.88	17.00		279.56
	1.09	1.70	2.46	3.35	4.38	5.56	6.88	8.35	9.97	11.74	13.67	15.75	18.00		265.00

 

[derby freak]

thanks Irvin that sure saves a lot of work bro and will be very handy at times i will save this to my computer for easy reference. Thank God for smart people in pwd it sure makes it easier for us not so smart ones.

 

[Minions Racing]

I used the equations at http://www.mathopenref.com/sagitta.html and plugged them into excel. One nice rule of thumb that others have probably noticed already, but it looks like a simple method of converting steer from 4 ft to 8 ft is to muliply by 4. So 3" => 12", 2" => 8", 2.5" => 10", etc. Not exact but pretty close.