Caster, mystery Options

[Randal]

I know how to set up toe in and camber, but not caster.

Questions:

How do you measure it and then reset it.

Also what is the stock caster setting and how will adding caster impact the amount of force needed to turn the wheel?

Also understand that adding caster will impact toe in and camber. At what setting does this impact begin.

All help appreciated.

[J P Stein]

Caster is the angle off vertical in the side view that the strut sits. ...leaned back on top. On a 914 it is set about 5.5 deg or more.
Caster does effect camber when the wheel is truned......the outside tire goes negative & the inside positive. Since camber, toe, & camber are all set with strut movement, they is all set at once....juggled, if you will, to what you want within the limits of adjustment. I like all the caster you can get on a 914....close to 6 deg.
This puts a good hunk of negative camber into the outside front durring conering.

Here's an old pic that shows the effect pretty well. Note the left front wheeel.

[Randal]

Caster is the angle off vertical in the side view that the strut sits. ...leaned back on top. On a 914 it is set about 5.5 deg or more.
Caster does effect camber when the wheel is truned......the outside tire goes negative & the inside positive. Since camber, toe, & camber are all set with strut movement, they is all set at once....juggled, if you will, to what you want within the limits of adjustment. I like all the caster you can get on a 914....close to 6 deg.
This puts a good hunk of negative camber into the outside front durring conering.

Here's an old pic that shows the effect pretty well. Note the left front wheeel.

So what do you measure the 5.5 degrees against. The strut or ?

[J P Stein]

So what do you measure the 5.5 degrees against. The strut or ?

Get the car level & use plumb. If no inclinometer use a small hand level on the strut & do the trig.....it's run vs rise then tangent.

[koozy]

Or, you can download an angle app on yer iPhone and slap it on the strut to measure the degrees.. Pick yer poison.

[Randal]

Caster is the angle off vertical in the side view that the strut sits. ...leaned back on top. On a 914 it is set about 5.5 deg or more.
Caster does effect camber when the wheel is truned......the outside tire goes negative & the inside positive. Since camber, toe, & camber are all set with strut movement, they is all set at once....juggled, if you will, to what you want within the limits of adjustment. I like all the caster you can get on a 914....close to 6 deg.
This puts a good hunk of negative camber into the outside front durring conering.

Here's an old pic that shows the effect pretty well. Note the left front wheeel.

So what do you measure the 5.5 degrees against. The strut or ?

I have some good angle measurement tools and my iphone app, so will try both. If the factory setup is 5.5 degrees (towards the driver) then what do racers typically run?

[koozy]

Most folks max it out but that makes it heavy on the hands. I'm using a bit less. It makes for a light steering car with all that rubber I have up front. If I switch to a narrower front tire I may go back to maxed out.

[URY914]

Mine is maxed out.

[SirAndy]

Just did this today. Mine was way off from left to right which made for some funny driving.

Maxed it out which is about 6 degrees with the stock strut tops.
(IMG:style_emoticons/default/driving.gif)

[J P Stein]

Ya'll got an app for my cracked & bleedin' ass?
Kids these days......

[koozy]

Ya'll got an app for my cracked & bleedin' ass?
Kids these days......

Will this help?

https://play.google.com/store/apps/details?...cButt&hl=en

[Randal]

Just did this today. Mine was way off from left to right which made for some funny driving.

Maxed it out which is about 6 degrees with the stock strut tops.
(IMG:style_emoticons/default/driving.gif)

So that was the weird handling "thing" we were talking about. Glad you found it.

[Randal]

Just did this today. Mine was way off from left to right which made for some funny driving.

Maxed it out which is about 6 degrees with the stock strut tops.
(IMG:style_emoticons/default/driving.gif)

Is this the correct way:

I put a straight edge across the cup that holds the shock bolt. My iphone app was flipping back between 9 and 10 degrees(*). So given that the floor is 2 degrees my caster is 8 degrees?

Not sure if this is the way to measure it, but isn’t that a bit high and a cause for my hard steering?

(*) The reading on the picture looks like 19 degrees, but the camera caught the app switching from 9 to 10 degrees.

[SirAndy]

So that was the weird handling "thing" we were talking about. Glad you found it.

Most of it it seems. There's still a bit of a "mushy" feeling and the alignment is not yet dead on, but the bouncing in corners is almost gone.

I know i still have a bit bump steer due to my current ride height (way up) and once that is dialed out and the alignment is spot on the car should drive *much* better.

The caster was off by several degrees between left and right. No idea how that happened.
(IMG:style_emoticons/default/blink.gif)

[r_towle]

Or, you can download an angle app on yer iPhone and slap it on the strut to measure the degrees.. Pick yer poison.

Considering how I have done this for years...I never thought to look for an app.

How very cool..
Gotta get me one for my android.

Rich

[Matt Romanowski]

Just did this today. Mine was way off from left to right which made for some funny driving.

Maxed it out which is about 6 degrees with the stock strut tops.
(IMG:style_emoticons/default/driving.gif)

Is this the correct way:

I put a straight edge across the cup that holds the shock bolt. My iphone app was flipping back between 9 and 10 degrees(*). So given that the floor is 2 degrees my caster is 8 degrees?

Not sure if this is the way to measure it, but isn’t that a bit high and a cause for my hard steering?

(*) The reading on the picture looks like 19 degrees, but the camera caught the app switching from 9 to 10 degrees.

You want to measure on the strut, not the cap. Caster is the measurement of the kingpin angle viewed from the side of the car. For MacPherson front ends, it's the angle of the strut. Google "alignment caster" and you'll see what you are supposed to be measuring.

Edit: Read the other scale - it looks like you have about 3 degrees (90-87). I would still say you should measure off the strut itself.

[Randal]

Thanks for the advice!

OK so measure against the strut as per the picture, i.e., the red arrow?

[Woody]

Thanks for the advice!

OK so measure against the strut as per the picture, i.e., the red arrow?

I would measure below the dust cover on the actual strut itself. My car is maxed out at 5.5 degrees.

[SirAndy]

I would measure below the dust cover on the actual strut itself. My car is maxed out at 5.5 degrees.

(IMG:style_emoticons/default/agree.gif)

Don't use the dust cover (if you still have one), use the strut itself. Now would also be a good time to see if there's a difference in angle between the strut and the shaft.
(IMG:style_emoticons/default/popcorn[1].gif)

[J P Stein]

Measure front face of strut tube....or insert (piston rod) in same, that is more uinform.
Keep the instrument parallell to the tube in X & Y.
App that with the machined surface of your cell phone.