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I have read a lot of threads on front end alignment and the seems to be quite varied.
I just realized that if I’m taking the car in on Friday, I had better have some specs to give him.
I am looking for street use...
I have slotted my upper cross shafts for extra caster.
Is there such a thing as “too much” caster. I keep reading that (with power steering) more can’t hurt and is better.
As for the rest, I think I read 1/32 toe in and 0 camber.
Do you have shim's to give to the shop ?. They most likely don't have stock and therefor may not be able to complete the job.
Also shim's for the rear trailing arms. Most shops will not have these, so its best you supply them. If they only do the front it's almost a waste of time.
Most shops don't know how to do the Rear Independent system. They won't have time to play with the Trailing Arms, TA shims, Strut-Rods or Cam Bolt.
If the Cam Bolt is frozen they will likely quit right there and do the front only. If the Strut Rod bushings have any slack, the show is over. And don't let them beat on the Strut Rods with a BFH.
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
If original from 1969 do this first!
If you have not changed the front trailing arm bushings and strut rod bushings and installed a new TA bolt and new shims the shop will not adjust the rear.
Geez ! How can they not have shims in stock. Good to know ! I told them what the car was when I made the appointment. They did not tell me to bring any.
The front suspension has been fully rebuilt. The rear: not yet. It is untouched. We are doing the front only. I am not even sure the shop can do the rear. I realize this is not ideal, but my goal here is to avoid a grossly out of spec front end and wrapping the car around the proverbial tree.
I guess, as this is a corvette, it makes sense to shoot for advanced street.
Those slotted cross shafts look like they may yield a ton of caster - like 7 degrees or more. What if it is up to 9 degrees ? What should I ask for at the shop?
If the Cam Bolt is frozen they will likely quit right there and do the front only. If the Strut Rod bushings have any slack, the show is over. And don't let them beat on the Strut Rods with a BFH.
I plan to put in adjustable rods and to redo the rear suspension this winter. No BFH bashing unless I am administering it.
Just do the rear camber along with all three up front. With stock cross shafts you can get up to about 4.75 castor. Which is a good thing. Later on I machined mine like your drawing .250 and I up my alignment spec to 6.5 castor.
Camber should be a negative value and it can only be determined by tire ware and a thermal heat gun if you are testing. I have found values of about .5 negative for both sides to work for most C3 vettes with good springs and shocks. Higher values are required with lower front spring rates and spirited driving. More front compression.
Toe in gives you car some self correction. I use "Zero" toe. Toe out makes a car nervous to drive. You would always be correcting with steering wheel input just to maintain a traffic lane going down the highway.
Make sure that they set up both sides the exact same. don't let them BS you about the crown in the road or that they couldn't.
So 6.5 castor
tiny toe in or "ZERO"
Try .55 degrees negative front and rear camber. THEN watch your inner tire ware to see if you need more or less
Just do the rear camber along with all three up front. With stock cross shafts you can get up to about 4.75 castor. Which is a good thing. Later on I machined mine like your drawing .250 and I up my alignment spec to 6.5 castor.
Camber should be a negative value and it can only be determined by tire ware and a thermal heat gun if you are testing. I have found values of about .5 negative for both sides to work for most C3 vettes with good springs and shocks. Higher values are required with lower front spring rates and spirited driving. More front compression.
Toe in gives you car some self correction. I use "Zero" toe. Toe out makes a car nervous to drive. You would always be correcting with steering wheel input just to maintain a traffic lane going down the highway.
Make sure that they set up both sides the exact same. don't let them BS you about the crown in the road or that they couldn't.
So 6.5 castor
tiny toe in or "ZERO"
Try .55 degrees negative front and rear camber. They watch your inner tire ware to see if you need more or less
I have read a lot of threads on front end alignment and the seems to be quite varied.
I just realized that if I’m taking the car in on Friday, I had better have some specs to give him.
I am looking for street use...
I have slotted my upper cross shafts for extra caster.
Is there such a thing as “too much” caster. I keep reading that (with power steering) more can’t hurt and is better.
As for the rest, I think I read 1/32 toe in and 0 camber.
The short answer is YES! To much caster will cause handling issues.
Typical settings in a perfect world would be:
Rear; 1/2 neg camber and 1/32 toe in
Front; 1/4 neg camber, 2 3/4 to 4 1/2 pos caster and 1/32 toe in
I buy my own shim sets with the holes through the top so that I can safety wire them together. In the past the bending forces of front 295 slicks and 700 lbs front springs caused me to loose a shim one day at the track. I was going over the big inside of the turn rumble cement strips. I worked at a shop and learned how to do my own alignments. Look at the modern performance car castor settings. That is why I chose to mod my cross shafts and use up toward 7 castor. Speed stability and it helps in turning
Going in for an alignment on Friday
No BFH bashing unless I am administering it.
