Hey, math guys (trig), help out an old carpenter

[randywebb]

- is there an equation for this degrees to inches conversion? if so, can somebody post it?

[Wil Ferch]

Randy:
The degrees-to-inches depends on the rolling diameter of the tire. My last post on this series of responses identifies a "graph" form of answer from Smart Racing Products.....

Wil

[porcupine911]

Originally posted by masraum
0.74605987818253310977060482416115

don't forget about significant digits homies.

[randywebb]

Thx Wil - I'll just make like an engineer and use the lookup .... ;-]

[Chuck Moreland]

Why did that feel like an insult? We Engineers know how to wield equations like a samurai his sword.

It's social grace that we lack.

Td = invTAN (Ti / D)

Where:
Td = toe degrees
Ti = toe inches
D = tire diameter

[thabaer]

know how to wield equations like a samurai his sword.

Range poles make great javelins after you've spent all day standing at a transit in a marsh 'cuz that's where the benchmark is!

It's social grace that we lack.

"Hey baby, wanna see my slide rule?" actually worked... more as a joke to a hottie in a summer field math course, but it still worked!

[Wil Ferch]

How's this for social grace ?

The Smart Racing products "link" shows both the graph AND the formula.......

Shall we put a bow-tie on this too

Wil

[randywebb]

feel like an insult

Sorry! Not intended to insult engineers. Perhaps an implied insult to scientists - such as myself - who are never really happy until several experiments are done and they match theory, which in turn goes down to the quark level....

[masraum]

I see where the confusion is coming in. (0.746059 vs .745997) The equation above assumes that 32' is the adjacent, where I assumed 32' was the hypotenuse.

I stand corrected. I think having the distance to the wall be one side, the 5" be the other side, and the remaining side be the hypotenuse is better than my way.

I just got lucky that the triangle is such an acute right triangle.

You guys are good.

[thastings]

Boy, even on this BBS surveyors have a hard time getting respect.
Charlie is correct. The tangent angle = 5"(0.416666666...' say 0.416667, opposite) divided by 32' (adjacent, since it is the centerline of the car) = 0.746002605 degrees or 0 deg 44 min 45.6 sec.

1" = 1/12 of a ft = 0.0833333...'

In the comps, you must convert inches to feet.

Terry Hastings, L.S.

[Zeke]

Originally posted by thastings
Boy, even on this BBS surveyors have a hard time getting respect.
Charlie is correct. The tangent angle = 5"(0.416666666...' say 0.416667, opposite) divided by 32' (adjacent, since it is the centerline of the car) = 0.746002605 degrees or 0 deg 44 min 45.6 sec.

1" = 1/12 of a ft = 0.0833333...'

In the comps, you must convert inches to feet.

Terry Hastings, L.S.

Wrong. 32' is not the adjacent from the centerline of the car. The Adj is from the rear rotors and corrected at the wall. So, it should be the same as the track of the front wheels as measured by the distance from outside face to outside face of rotor. The hyp is the angle or toe. It's all neutral now. No toe in or out either end and all is centered with repaest to the ceterline of the car. We'll see how it drives.

[thabaer]

Sounds just like a roomful of hardnosed en-gineers! Semantics, schmemantics... as long as Milt gets the beast off his patio and to the next meet without trashing his tires...Chuck gets us pics from the races...Steve finds a replacement for the missing '88... and I get my case put back together

Love this BBS

( and nobody zinged me for leaving the "..." off the end of my number )

[oldE]

Milt,
I think he meant to say "Adjacent, since it is PARALLEL to the centerline of the car"
Les

[masraum]

[thabaer]

Excacalactly! That's what I derived from Milt's original description, if I understood him.

So Steve, every time I see that frown in your sig I wonder when it will go away...hope for the future ?
( you probably already explained it in another thread but... )

[thastings]

This is a TOUGH crowd!!!!!!!!
Les is right, I assumed that the rear rotors were parallel to the centerline.
By the way the difference is 0.2 seconds of angle, or about 0.0017' (or 0.5mm), so even in the P-car quality of engineering, both are correct.
Terry