Stamped vs Cast K-Frame

[turbodaytona87]

Are the k-frames the same between cast and stamped arms? Which setup is better? I've heard the cast has a lower roll center, and better geometry. True?

[rbryant]

Yes the frames are the same, the arms are different.

The cast arms add more positive caster by moving the wheels forward. They do not change the up/down ball joint position. The better roll center is achieved from the 91 and newer knuckles.

I have a set of cast arms with new poly bushings if you need them. On my custom frame for the GLHS the wheels are too far forward with cast arms and can brush the fender extensions...

-Rich

[turbodaytona87]

I would be using the matching knuckles with whatever arms I chose Does the more positive caster occur with the matching arms and knuckles? How are later cars modified to fit those then?

PM me a price on the arms and busings, I might be very interested

[rbryant]

I would be using the matching knuckles with whatever arms I chose Does the more positive caster occur with the matching arms and knuckles? How are later cars modified to fit those then?

PM me a price on the arms and busings, I might be very interested

The caster is not changed by the knuckles (I did some research on this a while back) the only change is in the control arms.

The cast arms move things forward. If you look closely at the cast arms it is clear that the ball joint pads are machined off center specifically to accomplish this. If they were centered on the pad they would be in almost exactly the same position as the stamped arms.


Here is an overlay that I did. The ball joint centers are marked. C is for cast and S is for stamped. I measured between 3/8" and 1/2" (it is hard to do it accurately). Some might also vary slightly depending on the tooling they were machined on.

That means that the cast arms add about 1 degree of positive caster depending on your ride height. (from trig: arctan(.4/24) )



-Rich

[turbodaytona87]

Then how would a later Daytona differ front an earlier Daytona to fit the wheels without rubbing? Not doubting, just trying to figure everything out.

[shackwrrr]

werent the strut towers leaned back more?

[rbryant]

Then how would a later Daytona differ front an earlier Daytona to fit the wheels without rubbing? Not doubting, just trying to figure everything out.

They did move the front fenders forward a bit on the later daytonas.

I actually had them on a charger with a modified daytona frame. They cleared at full turn but were witin about 3/16" from the fender extensions. On a hard turn I think they could have hit.

A Daytona has more room than a charger but even then the early Daytonas with late model control arms have also been known to rub.

What year daytona do you have?

-Rich

[turbodaytona87]

I have an 87

[GLHNSLHT2]

stamped are lighter, you can use your stock knuckles or use the lightweight 11" 89/90 knuckles for 11" brakes. I have stamped on my 87 ShlebyZ and my 87 Yorker. Love them.

[turbodaytona87]

My knuckles fit? I'll probably go with the stamped then, makes life easier.

[GLHNSLHT2]

yep they fit.

[turbodaytona87]

I might just grab the brake setup too if its a dual pin, my calipers rattle like none other.

[turboz523]

Rich if you're still interested in selling those control arms and don't have a buyer let me know. I put your updated plates on today and switched to cast arms last night, I thinly one of them is bent cause the left.wheel is 1/2 inch closer to the front fender

[shadow88]

When I swapped from the factory 88 kframe, arms and rack to a 94 assembly, I noticed nothing more in caster measured on a hunter machine. I mean, I could shove it forward and gain caster, but not any more caster than the old kframe.

I thought the differences was in the body.

[turbovanman²]

When I swapped from the factory 88 kframe, arms and rack to a 94 assembly, I noticed nothing more in caster measured on a hunter machine. I mean, I could shove it forward and gain caster, but not any more caster than the old kframe.

I thought the differences was in the body.

I don't you gain caster on the newer setup, it just locates the ball joint in a different spot so it handles better. Sorry, can't think of the lingo,

[GLHNSLHT2]

Simon put down the alcohol. Changing the fwd and aft location of the ball joint will change caster.

[turboz523]

I have some before and after alignment specs from swapping parts on my car over the last few months. My baseline with all stock 89 daytona parts was -1.2*L and -1.2*R camber, 1.1*L and
.8* caster. Then I installed the camber plates and set the camber at -2.0* L and R, with the plates at the limits of adjustment for caster I got 2.0*L and 1.7*R. Next I swapped spindles from a 92 or so Dodge Spirit, with no other changes, my camber moved to 3.3*L and 3.1*R, no change in caster. This also moved the ball joint down about 1/2" to 3/4".
Friday I installed the lower control arms from the same 92 Spirit and checked the alignment again, 3.3*L and 3.0*R, so no change in the camber, 3.1*L and 2.2*R caster. This is where I noticed a problem, I think the right hand control arm is bent because it added alot more caster to the left side and the left side wheel is 1/2" closer to the fender than the right, the tire actually hits the inner fender well on tight turns.
Yesterday, I installed Rich's updated camber plates, with them adjusted for max caster I came up with 4.5*L and 3.1*R, at the same time I adj. the camber to -2.5 on both sides, which is where I want it, so now I just need to figure out whats bent and I'll be good to go.

[GLHNSLHT2]

If the wheel moved fwd then your caster had to have moved. Or the upper strut mount moved along with it.

You're running -2.5 degrees of camber? I hope you're autoXing the car only.

[turboz523]

yeah thats what I was saying, the newer control arms increased the caster, but I think one is bent because the left side increased 1.1* and the right only .5* and the left wheel is 1/2" further forward than the right. Yeah I pretty much just autocross this car now, its not my daily driver, then again work is only 3 miles up the road so I don't put that many miles on it.

[rbryant]

yeah thats what I was saying, the newer control arms increased the caster, but I think one is bent because the left side increased 1.1* and the right only .5* and the left wheel is 1/2" further forward than the right. Yeah I pretty much just autocross this car now, its not my daily driver, then again work is only 3 miles up the road so I don't put that many miles on it.

Interesting... 1/2" is an awful lot for a cast arm to bend though. Also the same side had less caster throughout your changes.

You might also want to check the kframe and do some quick strut tower measurements. The FSM should have a diagram for checking that the strut towers aren't tweaked. I have the 86 and 91 body manuals but don't have an 89 or I would scan the diagram for you.

-Rich