Front suspension experimentation
I found a good deal on a Wilwood disc kit for the 68 Valiant....so the trusty 9" drums had to go. While I had the car apart for that, I decided to also rebuild the front end as it was the all-original 55 year old pieces....still working well.
With all the talk about caster, I decided to make some upper arms to allow me to add more + caster. I wanted to stay with the small upper ball joints - because they are smaller and lighter - and I also used spherical bearings instead of bushings.
I think the 11/16" tie rods ends are unnecessary but they were half the price of the smaller originals so I used those and made some 7075 aluminum sleeves. The strut rods are pretty much a copy of the ones being sold by the aftermarket but I made my own as I think the aftermarket versions 'cheap out' by eliminating the tapered fit in the LCA.
The new UCA's allow me to go to about 6-1/2 degrees positive caster while still hitting 0 degrees camber. This also means that if I dial them back to 2-3 degrees positive caster, the cam bolts are positioned about midway which I think is better than having them maxed out.
For shocks, no one makes a good non-gas shock that I've found....I had the old Monroe Matics which still worked well but I also bought some Sachs gas-filled shocks to try.
So....I tried a bunch of different alignments with the camber at 1/2-3/4 degrees negative and the toe-in at 1/16".
1) I don't see a ton of difference in how the car drives as long as there is 'some' positive caster. Up at 6 degrees, you can feel the steering gets a bit harder, but I left the car at 3-1/4 degrees positive and everything seems OK. But it's not markedly different than 1 degree or even 1/2 degree.
2) The UCA uses spherical bearings that are Teflon lined....this probably adds some 'accuracy' to the suspension but hitting things like road reflectors is notably more noisy. The bearings are super-strong, over 50,000lbs load rating. But when you remove rubber from the suspension, it comes with a price. As for all guys who use polyurethane bushings (the worst of all IMO) for 'performance', all I can say is there's a reason Vipers and Corvettes come with rubber bushings.
3) The Wilwood discs are lot lighter than the 73+ factory discs but about the same weight as the 9" drums. I set them up properly, including bleeding until the pedal is rock hard. The pedal feel is less enjoyable than the drums, but I do like that I can do a hard stop from 60MPH without my hands on the steering wheel and the car will stop in a straight line and with more confidence.
4) The gas shocks work OK but raise the nose of the car by about 1/2" which I don't like....I want the torsion bars doing the suspension and the shocks doing the shock absorbing. I wish someone still made a good non-gas shock.
My final verdict is .... the stock suspension in good shape is pretty hard to improve upon for the average car. Maybe the mods I did (which seem to be "must do's" within the hobby are beneficial at the outer edges of competition but I don't drive like that and I doubt many do.
I found a good deal on a Wilwood disc kit for the 68 Valiant....so the trusty 9" drums had to go. While I had the car apart for that, I decided to also rebuild the front end as it was the all-original 55 year old pieces....still working well.
With all the talk about caster, I decided to make some upper arms to allow me to add more + caster. I wanted to stay with the small upper ball joints - because they are smaller and lighter - and I also used spherical bearings instead of bushings.
I think the 11/16" tie rods ends are unnecessary but they were half the price of the smaller originals so I used those and made some 7075 aluminum sleeves. The strut rods are pretty much a copy of the ones being sold by the aftermarket but I made my own as I think the aftermarket versions 'cheap out' by eliminating the tapered fit in the LCA.
The new UCA's allow me to go to about 6-1/2 degrees positive caster while still hitting 0 degrees camber. This also means that if I dial them back to 2-3 degrees positive caster, the cam bolts are positioned about midway which I think is better than having them maxed out.
For shocks, no one makes a good non-gas shock that I've found....I had the old Monroe Matics which still worked well but I also bought some Sachs gas-filled shocks to try.
So....I tried a bunch of different alignments with the camber at 1/2-3/4 degrees negative and the toe-in at 1/16".
1) I don't see a ton of difference in how the car drives as long as there is 'some' positive caster. Up at 6 degrees, you can feel the steering gets a bit harder, but I left the car at 3-1/4 degrees positive and everything seems OK. But it's not markedly different than 1 degree or even 1/2 degree.
2) The UCA uses spherical bearings that are Teflon lined....this probably adds some 'accuracy' to the suspension but hitting things like road reflectors is notably more noisy. The bearings are super-strong, over 50,000lbs load rating. But when you remove rubber from the suspension, it comes with a price. As for all guys who use polyurethane bushings (the worst of all IMO) for 'performance', all I can say is there's a reason Vipers and Corvettes come with rubber bushings.
3) The Wilwood discs are lot lighter than the 73+ factory discs but about the same weight as the 9" drums. I set them up properly, including bleeding until the pedal is rock hard. The pedal feel is less enjoyable than the drums, but I do like that I can do a hard stop from 60MPH without my hands on the steering wheel and the car will stop in a straight line and with more confidence.
4) The gas shocks work OK but raise the nose of the car by about 1/2" which I don't like....I want the torsion bars doing the suspension and the shocks doing the shock absorbing. I wish someone still made a good non-gas shock.
My final verdict is .... the stock suspension in good shape is pretty hard to improve upon for the average car. Maybe the mods I did (which seem to be "must do's" within the hobby are beneficial at the outer edges of competition but I don't drive like that and I doubt many do.