More caster

[Schnellvintage]

This was my car's specs with stock springs, strut mounts (new) and Poly bushings throughout.

Matt

[Tommy]

Stock setup above is at lower limits, lowered would be probably less. Still most of us have managed without messing with caster for street apps. I guess you need to do what you suggested to get where you want.

[Mike G]

Danjer_motorsports is making control arms that will increase caster and width. I think the next batch will just increase caster. 
 

 

[iinca]

I've played with more caster on other cars (Subaru/EVO) with off set bushings.... and it can be alotta fun 'at speed'. My STi had 6.5 degrees of castor and an 11.5  to 1 steering box.... and during one 150 mph run it felt solid as a rock (the only time I've ever gone that fast and it scared me enough to never do it again)

 

 As stated it does increase steering effort at low speeds.... but at speeds over 65 there was lots of stability 

 

Not sure how'd id do it with an 02. A shortened or adjustable tension rod would be nice... and moving the

strut mount backwards..

 

I thought about it but I think more important is having 'equal' caster and proper toe in (possibly a bit more if you want to get rid of that annoying dartiness)

 

Question: do you have big ass tires?

Edited March 30, 2020 by iinca

[Robocopywriter]

16 minutes ago, iinca said:

 

Question: do you have big ass tires?

Well not low profile because I wanted to keep the "period" look. 185/60 on 15s.  But they are Falkens and my experience with them is they have a pretty stiff sidewall.  Doesn't feel like a tire thing.  Response is very direct and it's predictable in hard corning.  In every other aspect the car is a blast to drive.

[iinca]

Maybe try a set of stock wheels and tires and see what happens... and possibly

eliminate some if not all of that jumpin' around on the freeway

Edited March 30, 2020 by iinca

[RussTii]

I would imagine this is how you would adjust caster: GT3 front subframe

[Mike A]

16 hours ago, Robocopywriter said:

At high Freeway speeds my car behaves a little like you would expect when there's insufficient caster, which now that I finished my 5 speed conversion has come in to focus.  It is a little darty and has a slight tendency to wander.  Although I have more adjustment available with Ground Control camber plates, they run out of room at the back of the strut tower and so I'm limited to only 3 degrees on both sides (at least I know my car is nice and straight).  I would like to reach the 4.5 degree limit but I would settle for for a least 4.

 

Has anyone solved this problem?  I'm thinking of using a burr cutting tool to make a little space just for that rear plate locking screw on each side.  Kind of like but not exactly like how I marked up in the pic.

 

I've searched the caster subjects on here but they all end up being about camber.  TIA.

Not having my turd ready for sorting yet, I've been concerned about the lack of suitable adjustment on these cars in stock form when I finally do get it on the road. Your diagnosis is  correct. Caster is what provides the centering force for straight ahead steering and marginal caster at speed is the cause (all other alignment specs, tires and suspension in good condition) of a car's instability. Toby's suggestion on control arms may be enough to do it for you.  I'm surprised your after market strut mount wasn't designed to include enough caster adjustment. When you turn the wheel in a slow speed turn, are you happy with it's return? If so  It  may only take another 1/2-1 degree. Has the car suffered any front end damage? 

Assuming there is enough free slot space left in the Ground Control I  think your suggestion of providing a bit more relief may be your answer. 

Edited March 31, 2020 by Mike A

[HBChris]

My NK sedan was wandering all over the freeway then I noticed my tire wear!  The toe was off as discussed earlier and now drives like a dream again.

[Robocopywriter]

4 hours ago, RussTii said:

I would imagine this is how you would adjust caster: GT3 front subframe

That would work.

[TobyB]

What

is

your

current

front 

toe????????????

 

 

Caster doesn't come up much because it's damned near impossible to change it,

either for good or for ill.  It doesn't go away any more than it magically appears.  If

your radius bushings are OK, it's stock.  Unless you bend HELL out of something, it's stock.

 

Bavaria lower arms with stock radius arms gives you something like 6.5 degrees (moves the bottom

forward about 5/8") and causes all sorts of other special functions to magically appear in your steering wheel.

 

t

has a box of casters in the barn

[Mike A]

^^^^ "Unless you bend HELL out of something, it's stock."    What he said.....that's what gives me a little concern. 6.5 degrees would be excessive methinks.

Edited March 31, 2020 by Mike A

[David Layton]

This was a good thread to read.  My car pulls to the right very slightly and under braking.  The last alignment showed the left castor was off.  The car will go back in to see if we can identify the issue, or what is bent.  The car has HR springs and 185 x 13 CN36's.  Also, previous owner had replaced the driver's floor and we know that it was not aligned, the original transmission mounts do not line up on the left and right sides of the tunnel.  With a 245 gearbox, we put in new mounts further back to hold the factory cross brace mount.  It is possible that misaligned floor panel is causing the caster issues.  We may need to install the ground control plates.

Edited March 8, 2023 by David Layton

[Son of Marty]

How old are the brakes? It could be a bad hose or stuck piston on the left side. I think a castor problem would show all the time.

[David Layton]

Marty,

 

The brakes and new brake lines were done when we put the car back together over the last 4 years.  Bimmers R Us in St. Louis did the alignment, and the measurements showed the caster was off.  He's going to re-check this to see if the control arm and strut are straight.  Should also measure the points on the chassis to see if it is slightly twisted.   It may be off a from the floor panel replacement.  In a way, I hope so.  My 02 is a tii and I do not want to find a bent strut. 

 

Edited March 8, 2023 by David Layton