When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You can elongate or notch the holes in the upper control arm shaft to enable you to move them back a half inch or so. I have seen someone on this forum do this and maybe they will chime in.
Last edited by Sacred Steel; 04-10-2016 at 12:05 PM.
You can elongate or notch the holes in the upper control arm shaft to enable you to move them back a half inch or so. I have seen someone on this forum do this and maybe they will chime in.
I did just this to my stock cross bar and I run 6.5 castor. It was easy to do on a Vertical milling machine
I road raced my Vette for a period of time and the main straight speed with my 434 sbc was about 156mph. I also have 295 front slicks and 275 width front street tires. Castor just allows you to relax at high speed and adds to braking and then turn in stability. I run Zero toe on the front so it just feels better and not nervous. All late model vettes have up around 7 castor
The offset upper control arm shafts like the MOOG K-6104 are offset 1/8” to correct too much negative camber only.
They are meant to fix a sagging front cross member when there are no more shims to take out to remove negative camber.
They do not in and of themselves change caster.
You might be able to shim more caster due to the change in shim thickness.
They do not change the for or aft location of the mounting bolts which is what will change caster.
Take the stock shaft plug the holes.
Move the new holes to the front of the car to move the a arm back.
I would suggest ¼”.
Doing it on a mill would be much easier than trying to drill half a hole.
I'm trying to visualise this, when you increase the castor does the wheel move forward in the wheel arch?
The top ball joint is moved rearward with increased caster, so the wheel would move rearward in the wheel arch opening, but almost imperceptibly. If you moved the upper arm back 1/4", the wheel would move back less than that, and have less effect to camber like shimming would. Because of the way the frame mounts are positioned, sliding the crossbar back will give you a little more negative camber.
I looked at slotting the cross shafts, I didn't like how the bolts would be at the edge of the square mounting pads and the fact that they're slots so it's possible for the arm to move in the slot, so I bought the Global West arms.
Just got it out of the alignment shop. The most caster he could get was 3.3* left, 3.7* right without adverse negative camber. Global West claims up to 6*, but I understand all frames are not equal. It is more stable, a real pleasure to drive on the highway, but if you can achieve the same results with modified cross shafts it would certainly be less expensive.
Just got it out of the alignment shop. The most caster he could get was 3.3* left, 3.7* right without adverse negative camber. Global West claims up to 6*, but I understand all frames are not equal. It is more stable, a real pleasure to drive on the highway, but if you can achieve the same results with modified cross shafts it would certainly be less expensive.
Is that with Global West A Arms??
3,3-3,7 can be done with stock arms and cross shafts.
The GW "road race" alignment has up to 6* caster but it also includes 1.5* negative camber. That's what the alignment tech told me he couldn't shim out while keeping neg camber reasonable. So all that is just as Global West stated in the instructions, but not in their sales pitch . The tech was concerned about adverse tire wear from that much camber, so he backed it off to .3* and .1* and we had to settle for the 3.3* and 3.7* caster. So not all frames are created equal it seems.
The GW "street" alignment is 3* to 3.5* caster and .5* negative camber, pretty close to what we wound up with. I do have C5 wheels and tires, IDK what a C5 spec is for camber, is it nearly 0*?
04-10-2016, 12:00 PM
. The tech was concerned about adverse tire wear from that much camber, so he backed it off to .3* and .1* and we had to settle for the 3.3* and 3.7* caster. So not all frames are created equal it seems.