tubular UCA's...worth it?

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Offline black71

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Re: tubular UCA's...worth it?
« Reply #15 on: August 21, 2007 - 12:22:34 AM »
the more the better?




Offline Chryco Psycho

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Re: tubular UCA's...worth it?
« Reply #16 on: August 21, 2007 - 12:46:00 AM »
it can help increase feel in power steering cars & often there is not enough adjustment to set the car properly for radial tires

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Offline HP2

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Re: tubular UCA's...worth it?
« Reply #17 on: August 21, 2007 - 08:46:33 AM »
the more the better?

The stock specifications for alignment call for negative to 1/2 degree positive. Typically 4-6 degrees positive makes a significant improvement in feel for average driving and/or strip passes. Stock arms with normal bushings can maybe get 2-3 degrees positive, offset Moog bushings can get you around 4-5 degrees in a stock arm. The tubular arms with an additional 2 degrees built in allows you to easily get to 4-5 degrees.

Offline amcmike

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Re: tubular UCA's...worth it?
« Reply #18 on: August 21, 2007 - 01:33:40 PM »
To add to HP2s comments, stock specs were intended for bias ply tires.  Radials really need more negative camber and more positive caster.
Mike
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Offline ChallengerHK

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Re: tubular UCA's...worth it?
« Reply #19 on: August 21, 2007 - 03:48:57 PM »
To add to HP2s comments, stock specs were intended for bias ply tires.  Radials really need more negative camber and more positive caster.

Granted that each car and driver is different, would anybody car to quote one or more sets of specs to target?


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Offline amcmike

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Re: tubular UCA's...worth it?
« Reply #20 on: August 21, 2007 - 04:24:58 PM »
Of course it depends on how the suspension is setup (torsion rates, rollbars, etc.).  Plus I'm not familiar with the rate of negative camber gain on an E-body.  But in general for a street car, I use:

Caster:  As much positive as possible (up to 6° with power steering, 2-3° with manual steering)
Camber:  Negative 1/4° to negative 1/2° static
Toe In:  1/32" to 1/8"

I'm sure someone may have more specific values for an E-body.

P.S. If anyone knows the camber gain rate for an E-body please speak up.
« Last Edit: August 21, 2007 - 04:31:25 PM by amcmike »
Mike
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Offline HP2

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Re: tubular UCA's...worth it?
« Reply #21 on: August 21, 2007 - 04:45:10 PM »
Like amcmike said, the factory specs were intended for skinny bias ply tires in an era where comfort and ease of driving were more important than driver feel and stability.

Only driving to the show and shine on radials at or below posted speeds with rebuilt stock suspension;
caster 2 positive
camber 0-.25 negative
toe 1/8 in

Like to cruise it regularly and have it feel real sporty at a normal ride height using offset bushings or tubular arms;
caster 4-6 positive
camber .5-1 negative
toe 1/16 in

Road racer in a lowered car with big rate bars and wide tires, wouldn't recommend it for the street;
caster 6-8 positive
camber 1.5-2 negative
toe 0-1/32 out

Before setting specs you MUST have the wheels and tires you intend to use and you MUST set the ride height first.  Tell the shop not to change the ride height when you give them specs.

A, B, and E bodies all have pretty linear and predictable negative camber gain through suspension travel. I forget the exact amount of gain per inch, but for a 40 year old design, it is decent. Switching to taller spindles will increase this gain as well. For those who don't know, as a car goes through a corner and the body rolls over, you want the outside tires to gain negative camber as the suspension compresses. This additional "camber gain" allows you to keep more of the tires tread on the surface of the road and maintain traction as opposed to have the tire roll up on its shoulder and compromise its traction.




Offline moparclown

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Re: tubular UCA's...worth it?
« Reply #22 on: August 21, 2007 - 06:30:13 PM »
Very enjoyable reading--The Clown

Offline ChallengerHK

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Re: tubular UCA's...worth it?
« Reply #23 on: August 21, 2007 - 06:44:55 PM »
Thanks, guys.  I will get on the front suspension project soon, and I may ask for more pesonalized number suggestions then.


"She'll make point five past light speed. She may not look like much, but she's got it where it counts, and I've made a lot of special modifications myself."

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Offline IMNCARN82

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Re: tubular UCA's...worth it?
« Reply #24 on: August 21, 2007 - 07:30:23 PM »
'73 340 5 speed,RMS,BAER,... "Supercuda" (O[   ]||||[   ]O)  
'69 Dodge Charger 383,Auto                  (OiiiiiiiiiiIiiiiiiiiiiO)
13' Challenger R/T BlacktoP  6spd. (OO________OO)
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Offline HP2

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Re: tubular UCA's...worth it?
« Reply #25 on: August 22, 2007 - 10:14:14 AM »
More info on camber gain; this is also a function of the control arm length. Shorter control arms will gain more camber as they cycle. Longer arms gains less. This is why a taller spindle gains more over a shorter spindle, it shortens the effective length of the control arm.

The rate of camber gain you wish to have is dependant upon the usage and surface you are running on. Flatter surfaces like the street or mildly banked tracks require more gain per inch, higher banked tracks require less gain. This is because on a flat track the car tends to roll over the imaginary line called the pivot axis and compresses the outside suspension significantly while unloading the inside suspension. On a high banked track, there is less body roll and more suspension compression on all four corners. The net result is less body roll requires less camber gain to keep the tire in contact with the road. This is why superspeedway cars use significantly higher spring rates than road course cars but road course cars use bigger sway bars, in general.

I think the stock mopar set up is around a hair less than 1 degree negative gain per inch of travel. Some cars, like first generation Camaros, actually go positive as they cycle up, which creates very unique handling dynamics that are at odds with the goal of keeping the tire flat on the ground. This is part of the reason why you see so many suspension companies out there selling GM upgrades. The easiest way to see the variations in dynamic camber change is super stock drag cars pulling wheelies. With a suspension at full droop, it should show some positive camber. Some go negative when they sholud be going positive and vice-versa under compression.

Offline dougs bs23

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Re: tubular UCA's...worth it?
« Reply #26 on: August 22, 2007 - 12:25:34 PM »
Very enjoyable reading--The Clown
I might actually learn something here :swaying:
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Offline IMNCARN82

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Re: tubular UCA's...worth it?
« Reply #27 on: August 23, 2007 - 06:03:04 PM »
Not to hyjack....but  i got a question.  these new 17" wheels/tires are wandering. I've had an alighnment,but I think it can be better. With some help... :1zhelp: i was thinking of bringing in some specs. to try. The shop is real road course/drag friendly. the owner races SCCA stuff. They don't get alot of these cars in and there's so much info. here I had to ask....                    they said they went off factory specs.     :worshippy
'73 340 5 speed,RMS,BAER,... "Supercuda" (O[   ]||||[   ]O)  
'69 Dodge Charger 383,Auto                  (OiiiiiiiiiiIiiiiiiiiiiO)
13' Challenger R/T BlacktoP  6spd. (OO________OO)
71' Demon
75' Duster
87' Conquest TSI
56' Plaza
Boulder CO
Robert    "cuda bob"

Offline Chryco Psycho

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Re: tubular UCA's...worth it?
« Reply #28 on: August 24, 2007 - 01:46:37 AM »
I would set it to HP2 2nd set up

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Offline black71

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Re: tubular UCA's...worth it?
« Reply #29 on: August 25, 2007 - 11:37:12 AM »
i still can't decide which ones to buy  :hyper: