Dangle_kt
|
| posted on 19/12/08 at 07:11 PM |
|
|
Self Centering Wishbones
I have read that the only way to properly fix the lack of self centering on 7's is to remake the front wisbones - thing is I'm crap at
fabrication, and can only ARC weld (I'll blow holes through tube easy)
So, my question is, with this well know design flaw documented - who makes wishbones that self centre?
I want to buy some rather than stuff my steering rack with springs! 
Thanks
|
|
|
|
|
jacko
|
| posted on 19/12/08 at 07:20 PM |
|
|
Hi is your chassis a [ The Book ] chassis ?
or a bought chassis ie mnr / mk / mac1 / etc etc
I have a MK indy some say they have problems with the steering but i don't seem to + it passed the sva first time
ps NO springs in mr rack
[Edited on 19/12/08 by jacko]
|
|
|
dinosaurjuice
|
| posted on 19/12/08 at 07:21 PM |
|
|
stuff steering rack with springs
surely no one in their right mind has done this?
making the top wishbone brackets 20mm wider allows the castor to be adjusted with spacers. maybe cheaper than buying complete wishbones.
Will
|
|
|
mad-butcher
|
| posted on 19/12/08 at 07:47 PM |
|
|
you better beleive it, Ford Sierra valve spring between rack body and tie rod hidden under rack gaiter
Linky to pic of Hellfires Fantastic wishbones
Sorry not the 1st pic but the one near the bottom
[Edited on 19/12/08 by mad-butcher]
[Edited on 19/12/08 by mad-butcher]
|
|
|
Dangle_kt
|
| posted on 20/12/08 at 12:32 AM |
|
|
its a live axle locost. It might not even be a problem, but I'd rather know where to go to get it sorted asap, as time is tight for SVA!
quote:
Originally posted by jacko
Hi is your chassis a [ The Book ] chassis ?
or a bought chassis ie mnr / mk / mac1 / etc etc
I have a MK indy some say they have problems with the steering but i don't seem to + it passed the sva first time
ps NO springs in mr rack
[Edited on 19/12/08 by jacko]
|
|
|
DavidM
|
| posted on 20/12/08 at 04:02 PM |
|
|
I made my top wishbones with 22mm more castor than shown in the book. This gives the 5.5 degrees stated in the book. It still doesn't self
centre.
For the SVA it only has to attempt to self centre. Turn to full lock and if when you pull away the steering moves slightly in the right direction,
that should be good enough.
David
Proportion is Everything
|
|
|
procomp
|
| posted on 20/12/08 at 04:32 PM |
|
|
Hi
Any locost type setups with 5 + degrees of Castor will self centre. Unless you have a set of very tight joints. In which case change them.
The majority of manufacturers that quote 5 degrees actualy rarely have. Some only have 2-3 degrees and some have as low as 1 on one side and 4 on the
other side due to poor jigging on both the chassis and the wishbones themselves.
The Castor needs to be relatively accurate and equal on both sides. A tolerance of 0.2 degrees would be acceptable for low volume production. Some
manufacturers run as high as 7 degrees as standard this gives very good feel from the front end when driving particularly when on a circuit. The ideal
is to build in adjustability either in the wishbones themselves of in the chassis bracketry.
A CEC will be fine with 5+ degrees and a BEC would benefit from 7 degrees. Depending on the upright being used. But in general 7 degrees is as far as
you are going to be able to go without introducing other associated geometry problems which will detract from the gain found from the extra Castor.
Cheers Matt
|
|
|
