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View Full Version : TF★ - What is caster? Stance Camber/Caster plate test results


tougefactory
02-18-2011, 01:52 PM
What is caster? Caster is the angle measured where the steering pivot axis is tilted forward, from vertical.
http://www.intraxracing.nl/UserFiles/File/CamberCasterToe/caster.pos.neg.gif

Increasing positive caster angle adds straight line stability, self centering of the steering, and camber gain. For drifting, added caster is beneficial for its ability to counter steer quickly and for quick transitions. For Grip, straight line stability for high speed, and camber gained turning turn-in can be a big advantage.

So you ask, "I know all this stuff, what's the point of this thread?". Good question. There are problems caused by the way the caster angle is changed on 240sx's. Only way to change caster is to use adjustable tension rods, by shortening the TC rods, you pull the wheels forward and effectively changing the caster angle.

By pulling the front wheels forward, you have now changed the geometry of the steering rack to the spindle. Theoretically this will increase ackerman and reduce total steering angle, which is not desired effect you want for performance.

To test our theory we put a S13 240sx with adjustable caster arms, coilovers(ride height set 2" lower than stock), stock inner and outer tie rods on our alignment system. Our state of the art system can measure "maximum turn angle", "Measured Ackerman" which we will be using for this test.
( I know its not a 240sx, the picture is to show you our alignment system :) )
http://tougefactory.com/tfworks/autogallery/galleries/012-jackie_ap1/DSC00366.jpg

1st test - Stance GR+ with standard camber plates, Stance Tension rods, Stock inner and outer tie rods. Ride height was set to 2.5" lower than stock.
We set the initial alignment setting to what we typically set most of the s13's with street tires. Caster - 7.1 deg, camber 3.5 deg, toe - 0 .
Max turn angle : 34 deg
Measured ackerman : 58%

2nd test - Stance GR+ with camber/caster plates. Stance Tension rods, stock inner and outer tie rods. For this test, we adjusted the tension rods to get the tie rods to sit close to 90deg to the spindle, this also centered the wheel in the wheel well. Caster was around 6deg at this setting. We than installed the Stance camber/caster plates and adjusted the caster to 7.1 deg. Camber was set to 3.5 and toe was set to 0. This way we minimize any variables.
Max turn angle : 39 deg
Measured ackerman : 51%

What does this mean?

Ackerman geometry was developed for low speed maneuverability.

For racecars, less ackerman is desired. Decreased ackerman will result in better initial turn-in response. For high speed racecars, decreased ackerman geometry is used to compensate for the large difference in slip angle between the inner and outer tires while cornering. This can reduce tire temps and increase traction during cornering.

Conclusion :
Drifting: Caster/Camber plate will increase angle and faster counter steer for transitions. Also reduce the effect of steering overcenter. Increase in 5 degrees of angle with stock inner/outer tie rods, with spacers in conjunction with camber/caster plate, you should be able to gain 8-10 degrees. That's modified knuckle category...:)

High Speed Grip: Caster/Camber plate will get the benefits of increased caster angle without increasing ackerman.

Low speed Auto X : Caster/Camber plate will reduce caster for faster steering and increase ackerman for low speed maneuverability.

Stance Camber/Caster plate will +/- around 1.5 to 2 degrees of caster depending on your camber setting.

http://www.tougefactory.com/tfdave/st_camcas.jpg
http://www.tougefactory.com/tfdave/st_camcas2.jpg

MattRose
02-18-2011, 02:10 PM
Fantastic writeup guys!

I posted it here:
http://forums.613driftwerks.ca/showthread.php?p=80073#post80073

On our local forum for all the guys who don't make it out to Zilvia, I hope you don't mind:D

Offtopic, but I have a 1994 R33 Gts25t, can you PM me the pricing for some stance GR+ and the estimated wait time?

Cheers!

shiftdrift
02-18-2011, 02:21 PM
excellent writeup, this is why touge factory is the shit.

tougefactory
02-21-2011, 12:34 PM
No problem!

Check your PM

tougefactory
02-21-2011, 12:35 PM
excellent writeup, this is why touge factory is the shit.

Thanks for your support!

Patrick Bowering
02-23-2011, 07:15 PM
Does anyone know if these are compatable with bc racing coilovers? I doubt it but im hoping they are.

'97 S14 SE Turbo
02-23-2011, 10:00 PM
Got specs/dimensions of the center bearing hole size? Would like to see if it will fit Zeal coilovers.

tougefactory
02-24-2011, 11:34 AM
Does anyone know if these are compatable with bc racing coilovers? I doubt it but im hoping they are.

Measure the ID of the pillowball.

tougefactory
02-24-2011, 11:34 AM
Got specs/dimensions of the center bearing hole size? Would like to see if it will fit Zeal coilovers.

PM me the ID of the pillowball. I will let you know

OBEEWON
02-24-2011, 11:55 AM
That Akerman dude is such a downer. The less I get of him the better.

lflkajfj12123
03-20-2011, 07:40 PM
Stance #1                   

slideways90
03-20-2011, 07:52 PM
ill measure the my id of my upper pillow ball tomorrow i want these.

Tearlessj
12-10-2011, 01:08 AM
Question, will a average alignment shop be able to set these for me? or will I have to go to a race shop?

ShakotanGazelle
12-10-2011, 11:06 AM
would these fit on other coilovers? or just on Stance coilovers?

Howie Felter Snatch
12-11-2011, 02:57 AM
A normal alignment shop wouldn't know what the fuck they're looking at with non-oem arms and coilovers with caster/camber adjusting plates.. lol..

future
12-11-2011, 06:56 AM
Not true. I always got my car aligned and I just let the. Know and they fixed it. Some places will charge extra though

Tearlessj
12-11-2011, 11:36 PM
Well I know the guys at my alignment shop very well. They drive 240's as well, just wondering if there is special equipment needed besides a normal hunters rack.

LayNLow
12-17-2011, 02:35 AM
Nah Judd, a regular rack should be fine. Not like your trying to get a readout of your exact ackerman and steering angle. Just find out how they work and let the tech know how to adjust them. Done and done. I cant wait for my taxes to come in. MMMM goodies!

AutoRnD
04-12-2012, 03:28 PM
Great Writeup. We will be including camber caster plates with our S-chasis coils now.

g00se
04-13-2012, 05:34 PM
fit KW variant 3's? I would rather buy these than the T3 ones

MadScientist
04-13-2012, 05:58 PM
Ummm... you guys realize that the Stock Tension Rods with their Huge bushing is designed with this in mind already, and by replacing it with rigid Tension rods you are eleminating this movement?

No, I am not saying anyone should revert back to those useless dry rotted, weak stock rods.

Stance - Great job putting the factory suspension geometry back in use.
TF - Thanks for educating everyone.

SicBastard
04-03-2014, 08:34 AM
"Low speed Auto X : Caster/Camber plate will reduce caster for faster steering and increase ackerman for low speed maneuverability."

Did you mean OR rather than AND? And wouldnt you reccomend the higher ackerman set up for autocross?