does anyone make shortened knuckles where the top part that connects to the upper A arm is shortened so the upper arm sits straight on a lowered car?

 

that would be way too optimistic.

would cost way too much to make.

even function7 looked into it, they came to the same conclusion.

 

really? it doesnt sound hard to implement at all, i suppose cutting out a section and rewelding would be out of the question ...

 

huh??? i'm lost

 

Yea I was thinking about shortning mine aswell. The plan of attack was to cut out a section and then place a hollow sleeve over the ends and bolt and weld it back together

 

you guys gotta make sure that your tire isn't going to contact the upper ball joint it it you remove to much

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shadycrx &raquo;</TD></TR><TR><TD CLASS="quote">does anyone make shortened knuckles where the top part that connects to the upper A arm is shortened so the upper arm sits straight on a lowered car?</TD></TR></TABLE>
That would give you a really crappy camber curve. The UCA could not be shortened enough to gain back the negative camber you'd lose because the coilover assembly has to go through it. As someone else mentioned, you'd probably have clearance issues as well.

 

there is the ryane motorsports knuckle. not made for a while though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">
That would give you a really crappy camber curve. The UCA could not be shortened enough to gain back the negative camber you'd lose because the coilover assembly has to go through it. As someone else mentioned, you'd probably have clearance issues as well.</TD></TR></TABLE>

are you talking about shortening the actual control arm?? im just talking about shortening the nearly straight piece of knuckle that goes up to it about 1 inch to make up for the lowered body so the upper arm could sit straight..er... the only issue with cut and weld is of course safety and a messed up camber

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shadycrx &raquo;</TD></TR><TR><TD CLASS="quote">

are you talking about shortening the actual control arm?? im just talking about shortening the nearly straight piece of knuckle that goes up to it about 1 inch to make up for the lowered body so the upper arm could sit straight..er... the only issue with cut and weld is of course safety and a messed up camber </TD></TR></TABLE>
You're missing what I am saying. Shortening the knuckle will reduce negative camber, so you'd have to reposition the ball joint further inboard on the UCA to gain that camber back - thus you'd probably need a custom UCA to go with the custom knuckle. I am questioning whether or not the UCA can be modified to do this.

 

theres nothing stopping you from trying. if you know someone who can weld it back together with some degree of accuracy, and youre willing to drive around on welded knuckles, then go ahead. try it and let us know...

 

What are the knuckles made of?

 

Well mine are made from bone and cartilage.
LOL,
I think they are made from cast iron.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Speed--Freak &raquo;</TD></TR><TR><TD CLASS="quote">
I think they are made from cast iron.</TD></TR></TABLE>

Exactly what i thought, in which case it takes a very experienced person to weld that up, and even then i wouldnt trust it. I would take my chances on a repaired/welded stock exhaust manifold, but not on a knuckle.

 

welding cast iron?...hmmmm that sounds like a real bad idea

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Targa250R &raquo;</TD></TR><TR><TD CLASS="quote">You're missing what I am saying. Shortening the knuckle will reduce negative camber, so you'd have to reposition the ball joint further inboard on the UCA to gain that camber back - thus you'd probably need a custom UCA to go with the custom knuckle. I am questioning whether or not the UCA can be modified to do this.</TD></TR></TABLE>

Agreed, and reducing the length of the upper control arm (or lowering that top ball joint on the knucle) will result in raising the dynamic roll center of the car too. This is beacause the upper arm is now more "horizontal" and if you spend the time to project the locus of movement of the arm, you'll realize the DRC will rise. This can be a good OR bad thing, but more often than not it's the latter.

FYI (for the benefit of those interested)
Dynamic Roll Center - this is the virtual axis in which the body rolls. Combine this with the CG of the car and you can predict lateral roll characteristics. The term "Dynamic" indicates that this roll center is dependent on how the car sits and it varies as the suspension moves up/down.

-A

 

the guy just wants to shorten it so he can ride lower. what does he care about dynamic roll centers...

 

so having the upper ball joint sitting at such an extended angle, how much of a proble is this? Would it be benificial to modify the ball joint so it sat at a different angle?

For sake of arguement, If you got around the detrimental effects of cutting and rewelding cast iron, and tire clearence... how exactly would it effect the car, in terms of DRS, and over all handling. We need a physics lesson.

 

It wouldn't be that difficult to section a knuckle (removing an inch) and welding it back together. You would want to bevel both ends and fillet weld it. You could then weld gusset plates over the modified area. All of this should be done by a certified welder!!!

It would be a lot easier to modify the upper box section of the body for clearance and then box it to replace the lost strength.

As for it changing the dynamic roll center, my guess (and that's pretty much all it is) would be that you would be making it better than what it would be with a stock knuckle. The reason for that thinking is that when a car is lowered a lot with stock configuration arms, the upper arm sits at a fairly extreme angle to horizontal. Lowering the upper ball joint would get the angle a little more reasonable.


Wes

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">the guy just wants to shorten it so he can ride lower. what does he care about dynamic roll centers...</TD></TR></TABLE>

meh- i care.

here's an old thread with info from people more informed than i for those that are curious.

https://honda-tech.com/zerothread?id=1223084

the first link in that thread has a good drawing for anyone who doesn't get the concept technobabble without a visual.