72 front end shudder and dancing/not tracking.
10-17-2022, 05:39 PM
#21
Team Owner
First get a shock tower bracer bar. That will stiffen up the front suspension. Next make sure your steering box is setup correctly. If there is little to no lash in the box you will not self center out of a turn.
10-18-2022, 10:45 AM
#22
Team Owner
Thanks for all the help, car is doing better.
I did the Force Road Balancing and tires and wheels seemed ok, I moved the two that had a slight spot in them to the rear.
All tires are inflated to 32 PSI.
I checked the Power steering control and it was and is balanced. I adjusted it and found it OK.
I had a front wheel alignment to gkull recommendations and following is the report.
The car drives better, seems tighter and not as loose or "darty". I like the feel but wish it would return to center when the wheel is released coming out of a turn. I think this was improved somewhat, however I still have to steer it back straight.
I am defiantly on the right track and the cars is more enjoyable to drive.
I did the Force Road Balancing and tires and wheels seemed ok, I moved the two that had a slight spot in them to the rear.
All tires are inflated to 32 PSI.
I checked the Power steering control and it was and is balanced. I adjusted it and found it OK.
I had a front wheel alignment to gkull recommendations and following is the report.
The car drives better, seems tighter and not as loose or "darty". I like the feel but wish it would return to center when the wheel is released coming out of a turn. I think this was improved somewhat, however I still have to steer it back straight.
I am defiantly on the right track and the cars is more enjoyable to drive.
10-18-2022, 11:34 AM
#24
Team Owner
10-18-2022, 04:10 PM
#25
Le Mans Master
Thanks for all the help, car is doing better.
I did the Force Road Balancing and tires and wheels seemed ok, I moved the two that had a slight spot in them to the rear.
All tires are inflated to 32 PSI.
I checked the Power steering control and it was and is balanced. I adjusted it and found it OK.
I had a front wheel alignment to gkull recommendations and following is the report.
The car drives better, seems tighter and not as loose or "darty". I like the feel but wish it would return to center when the wheel is released coming out of a turn. I think this was improved somewhat, however I still have to steer it back straight.
I am defiantly on the right track and the cars is more enjoyable to drive.
I did the Force Road Balancing and tires and wheels seemed ok, I moved the two that had a slight spot in them to the rear.
All tires are inflated to 32 PSI.
I checked the Power steering control and it was and is balanced. I adjusted it and found it OK.
I had a front wheel alignment to gkull recommendations and following is the report.
The car drives better, seems tighter and not as loose or "darty". I like the feel but wish it would return to center when the wheel is released coming out of a turn. I think this was improved somewhat, however I still have to steer it back straight.
I am defiantly on the right track and the cars is more enjoyable to drive.
Last edited by interpon; 10-18-2022 at 06:56 PM.
10-18-2022, 07:32 PM
#26
Team Owner
The rear setting for toe is a big time consuming deal with shims. Rear camber really needs smart struts and and adjustable strut rods
10-18-2022, 07:52 PM
#27
Le Mans Master
You got a 2 wheel alignment…
i would take a look or pics of those rear trailing arm bushings as well.
i understand they were replaced but maybe they are still bad or bad poly etc.
i would take a look or pics of those rear trailing arm bushings as well.
i understand they were replaced but maybe they are still bad or bad poly etc.
Last edited by interpon; 10-18-2022 at 07:59 PM.
10-18-2022, 10:04 PM
#28
Old Pro Solo Guy
I do not know if they touched the rear toe.. The slight difference is probably just measurement or setup error.
.29 degrees rear toe in is 1/4 inch.
That is about double what Gkull, Van Steel and I recommend for a street C3.
Plus the right rear camber is way too steep at 1.7 degrees. At the most it should be half that, or 1/3.
The combination of high camber and large toe-in is a real tire killer. It will wear the inside edge badly, may develop cupping and shudder. The inner edge will die 4x faster than the rest of the tire.
Agreed the rear toe-in is a PITA to adjust with the shims. Just bring them a pack of shims and have them do it. Be willing to pay them for their time.
But first you need to fix the RR camber. That is also a PITA with the factory eccentrics, sometimes they freeze, and sometimes just can't move things enough. That's why many C3s get bent rear strut arms, to shorten them, but that is not the correct way to do it, just fast. What you should do is purchase adjustable rear strut arms first, then go back and have them install them and have the rear alignment fixed / re-done.
They did a ggod job with the front, it is much more conventional after all, and they doubled the caster, which should help a lot with going straight and self-centering. 4 degrees is probably about all you can get with stock front parts, and probably good enough for what you are trying to do.
But front toe-in is still a little high, at .56 degrees it is almost 1/2 inch. That will deaden the steering response. I would cut that back to close to zero as GKull recommended.
Possibly they got confused in the specs you gave them? Especially if you gave them specs in inches? and used degrees instead of inches? Most shops / alignment machines deal in degrees these days.
GKulls recommended 1/32" to 3/16" front toe in translates into 0.033 to 0.199 degrees.
1/8" rear toe-in translates into 0.133 degrees.
You are double to triple on both.
.29 degrees rear toe in is 1/4 inch.
That is about double what Gkull, Van Steel and I recommend for a street C3.
Plus the right rear camber is way too steep at 1.7 degrees. At the most it should be half that, or 1/3.
The combination of high camber and large toe-in is a real tire killer. It will wear the inside edge badly, may develop cupping and shudder. The inner edge will die 4x faster than the rest of the tire.
Agreed the rear toe-in is a PITA to adjust with the shims. Just bring them a pack of shims and have them do it. Be willing to pay them for their time.
But first you need to fix the RR camber. That is also a PITA with the factory eccentrics, sometimes they freeze, and sometimes just can't move things enough. That's why many C3s get bent rear strut arms, to shorten them, but that is not the correct way to do it, just fast. What you should do is purchase adjustable rear strut arms first, then go back and have them install them and have the rear alignment fixed / re-done.
They did a ggod job with the front, it is much more conventional after all, and they doubled the caster, which should help a lot with going straight and self-centering. 4 degrees is probably about all you can get with stock front parts, and probably good enough for what you are trying to do.
But front toe-in is still a little high, at .56 degrees it is almost 1/2 inch. That will deaden the steering response. I would cut that back to close to zero as GKull recommended.
Possibly they got confused in the specs you gave them? Especially if you gave them specs in inches? and used degrees instead of inches? Most shops / alignment machines deal in degrees these days.
GKulls recommended 1/32" to 3/16" front toe in translates into 0.033 to 0.199 degrees.
1/8" rear toe-in translates into 0.133 degrees.
You are double to triple on both.
The following users liked this post:
interpon (10-18-2022)
10-18-2022, 10:24 PM
#29
Le Mans Master
but I think all parts supposed to be recently replaced so everything should be moveable as is..
buy the shims (chances are they don’t have) and there is a good chance they may not know how to adjust rear or mess with it, but you did not get a 4 wheel alignment.
dont assume specialty shop is needed either. I went to a chain and they often have master mechanics that rotate or do specialty work or train. Find a guy tip well and only use him.
op, here is my journey..post some pics of your bushings and shims.
https://www.corvetteforum.com/forums...-advice-2.html
more shimsand power steering valve alignment
https://www.corvetteforum.com/forums...uestion-3.html
shims here
https://www.topflightautomotive.com/...-hardware-kit/
Last edited by interpon; 10-18-2022 at 10:35 PM.
10-19-2022, 08:49 AM
#30
Team Owner
This is the best improvement for a C-3 rearend. Then you can do rear camber at home with a digital level
https://www.corvettemods.com/C2-C3-C...hoCANwQAvD_BwE
https://www.corvettemods.com/C2-C3-C...hoCANwQAvD_BwE
10-28-2022, 06:27 PM
#31
Racer
Thread Starter
Sorry for the late response, I have been traveling. Thank you for the comments.
I only had the front done, and yes we had some challenges converting degrees to inches.
GKull can you give me a suggested toe for both front and rear in degrees? I'll try to get it back in the alignment shop in the next few weeks. And check/adjust both front and rear.
Thank you
I only had the front done, and yes we had some challenges converting degrees to inches.
GKull can you give me a suggested toe for both front and rear in degrees? I'll try to get it back in the alignment shop in the next few weeks. And check/adjust both front and rear.
Thank you
10-30-2022, 03:01 PM
#32
Old Pro Solo Guy
Daily Driver - These specs are designed to minimize tire wear and dynamic forces on front end parts. Driver effort is minimum, the car will steer very "light" and may wander or be "darty" on road with wear ruts. If you are uncomfortable with this feeling, toe the car in up to a maximum of 1/8" total toe in.
Advanced Street - These specs are designed to give an even quicker steering response with minimum tire wear. If the car is "darty", toe the car in. By toeing in, you may loose some turn-in qualities gained by the initial specs.
Front
63 - 82 Corvette
Daily Driver Toe 1/32" in Camber 0.5° neg Caster 2.75° pos (1/32" toe-in translates into 0.033 degrees.)
Advanced Street Toe 0" Camber 0.5° neg Caster 4.75° pos (0" toe-in translates into 0.0 degrees.)
Autocross Baseline Toe 3/16 out Camber 1.5-2° neg Caster 2.75° pos (3/16" toe-OUT translates into 0.199 degrees.)
Track Baseline Toe 0-1/16 out Camber 1-2° neg Caster 4.75° pos (1/16" toe-OUT translates into 0.067 degrees.)
Rear
63 - 82 Corvette
Daily Driver Toe 1/8" in Camber 0° neg (1/8" toe-in translates into 0.133 degrees.)
Advanced Street Toe 1/8" in Camber .50° neg (1/8" toe-in translates into 0.133 degrees.)
Autocross Baseline Toe 1/16” in Camber .75-1.5° neg (1/16" toe-in translates into 0.067 degrees.)
Track Baseline Toe 1/8” in Camber .75-1.5° neg (1/8" toe-in translates into 0.133 degrees.)