Early steel control arm as a mechanical fuse
02-28-2013, 10:46 AM
#17
Rennlist Member
Can anyone show me a picture of the whole unit modified to an alum arm car?
I have rebuilt arms in my car with 968 m030 caster blocks and sways. Is it possible to run those withe early arms as I already have a lot of money invested in the current setup, however the steel arms have always interested me.
I have rebuilt arms in my car with 968 m030 caster blocks and sways. Is it possible to run those withe early arms as I already have a lot of money invested in the current setup, however the steel arms have always interested me.
02-28-2013, 08:43 PM
#18
Race Car
I have steel arms in my car, everything bolts right up. I used the 968 castor blocks, they work as well the only down side you can't adjust them.
The cost to convert with new parts from paragon was around $250 then I bought cheap 968 castor blocks for like $120. If you don't use the 968 caster you need to puchase the caster clip (75 each new) and new bushings as well.
Early Parts List to Convert:
Steel Arms
Ball Joints
Sway Bar Mounts
Sway Bar Bushings
Castor Clips
Castor Bushings
Control Arm Bushings
Hardware, especially for balljoints
Note: KY Jelly does excellent to press bushings in using a vice,
don't tell my wife.
The cost to convert with new parts from paragon was around $250 then I bought cheap 968 castor blocks for like $120. If you don't use the 968 caster you need to puchase the caster clip (75 each new) and new bushings as well.
Early Parts List to Convert:
Steel Arms
Ball Joints
Sway Bar Mounts
Sway Bar Bushings
Castor Clips
Castor Bushings
Control Arm Bushings
Hardware, especially for balljoints
Note: KY Jelly does excellent to press bushings in using a vice,
don't tell my wife.
02-28-2013, 09:11 PM
#19
Rennlist Member
Hey Rob,
Can you take pics of the setup on your car? Can you adjust the early caster blocks? If not is there a down side to using my current M030 blocks? How do the sways mount and will my 30 mm, 968 M030 sways be to stiff for the steel arms?
Can you take pics of the setup on your car? Can you adjust the early caster blocks? If not is there a down side to using my current M030 blocks? How do the sways mount and will my 30 mm, 968 M030 sways be to stiff for the steel arms?
03-02-2013, 07:53 PM
#20
Burning Brakes
I'm also a big fan of the steel control arms.
I converted after a fender bender where my old aluminum control arm shattered in 2 pieces and also shifted the impact force towards the caster block mounting and bent it slightly.
Here's how it looked
I converted after a fender bender where my old aluminum control arm shattered in 2 pieces and also shifted the impact force towards the caster block mounting and bent it slightly.
Here's how it looked
03-03-2013, 02:32 PM
#24
Burning Brakes
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I wish there was an easy way to do it on the late cars. $750 for the Blaszak parts just isn't a good deal, considering you can get some tubular arms (that work with the 968 M030 and 968 caster blocks) for a few hundred more.
What's the exact difference? I'm assuming the balljoint-to-mount length is a little less on the early cars (narrower)? Anybody have a DIY reference?
What's the exact difference? I'm assuming the balljoint-to-mount length is a little less on the early cars (narrower)? Anybody have a DIY reference?
03-03-2013, 04:45 PM
#25
Burning Brakes
I wish there was an easy way to do it on the late cars. $750 for the Blaszak parts just isn't a good deal, considering you can get some tubular arms (that work with the 968 M030 and 968 caster blocks) for a few hundred more.
What's the exact difference? I'm assuming the balljoint-to-mount length is a little less on the early cars (narrower)? Anybody have a DIY reference?
What's the exact difference? I'm assuming the balljoint-to-mount length is a little less on the early cars (narrower)? Anybody have a DIY reference?
xschop has the exact dimensions
03-05-2013, 03:12 AM
#26
RL Community Team
Rennlist Member
Rennlist Member
Yeah, I'm not paying $750 for steel arms, that defeats the purpose. I'm going to try to make them myself. I have a friend who's a blacksmith and a better welder than I am, I'm sure he can help.
03-05-2013, 09:17 PM
#27
Three Wheelin'
Thread Starter
Has anyone here experienced/seen/heard about factory steel arms bending due to NORMAL track use (just from the stresses of being loaded by sticky tires, large lateral loads and big sway bars)? Of course any arm will bend if one makes a stupid mistake like I did and put a wheel off and it impacts, but the impetus of my original post was to find out whether it is even worth it to box the arms. In my experience thus far with the Lemforder arms it is not.
03-05-2013, 09:35 PM
#28
Rennlist Member
Has anyone here experienced/seen/heard about factory steel arms bending due to NORMAL track use (just from the stresses of being loaded by sticky tires, large lateral loads and big sway bars)? Of course any arm will bend if one makes a stupid mistake like I did and put a wheel off and it impacts, but the impetus of my original post was to find out whether it is even worth it to box the arms. In my experience thus far with the Lemforder arms it is not.
Eric Steinel (well known shop in Cleveland) tells a good story of when he was on Fred Baker's team running the 944 Turbo prototypes in the Playboy/Escort 24 hr endurance races at Nelson Ledges and Mid Ohio in '83 and '84. One of the cars broke a steel front control arm and the Porsche engineers from Germany referred to the steel arms as "VW Scheisse", which is where the development of the aluminum arms came from.
There are well documented alum arm failures going back to the late 80's. But most are the weaker '86 arms, and most of those were using aftermarket front sway bars (weltmeister), which had the solid mounting bushings on the control arm (they used to be aluminum bushings, not sure if they still are). Problem with that, and with any of the solid sway bar mounting parts, the control arms and the sway bar pivot in different planes. If there is no rubber to allow flex, binding occurs in the suspension range of motion, and the stresses at the mounting points become huge. So most of the aluminum arm fractures were at the swaybar mounting points (this is a separate issue from the balljoint failures).
Late arm failures of the casting itself, are relatively unheard of if using factory swaybars (including the 968 M030 bar) and retaining the rubber mounts.