View Full Version : 1973 Nova old school conversion
409novaman
10-31-2019, 09:33 AM
I have a 1973 Nova Custom 2dr and I’m upgrading the suspension.
The car has a small block, aluminum heads, aluminum water pump, aluminum intake, header and no air conditioning. It is also a factory disk brake car and is running a Hotchkis front sway bar.
I want modern handling from my Nova, it will not be raced, but I need some help from you with my project.
I just bought a set of Speedtech upper and lower control arms from Matt’s Classic Bowties, after much research.
I have a limited budget, so every dollar counts. I’m an old guy and I’m not into laying on the garage floor making numerous Experimental changes to the suspension. I’m trying to do it right the first time.
My next purchase will be Viking dual adjustable hybrid coil-over shocks.
Questions:
1. 450lb springs? (Don’t forget those bumpers)
2. .5 or .9 upper ball joints?
3. .5 lower ball joints to drop the car or leave it alone?
3. Proforged tall tie rod ends?
I’ll leave the questions at this point, my arthritis is killing me, I’m looking forward to the garage floor. I’ll have more questions as my winter project continues.
BTW: about the ball joint question, I’ve checked search and the answers don’t seem conclusive, the experts seem to disagree.
409novaman
11-03-2019, 04:49 AM
Just thinking to myself here, I could use the Ridetech tall spindle with the 2" drop rather than all the ball joints. It costs about the same.
Dropping the spindle 2" isn't a problem:
https://73novacustom.blogspot.com/2014/02/sorting-out-bump-steer.html
Sorting out the Bump Steer
Now that the front end is so low I have some bump steer issues to resolve. Bump steer manifests itself when the suspension loads or unloads from a bump in the road. Bump steer often occurs when one lowers (or raises) the front end and the tie rods become misaligned relative to the lower control arm. They need to be parallel or the tie rod will swing on a different arc as the control arm. The shorter or longer arc will cause the wheels to turn while the steering wheel stays still. Bump steer = thrill ride.
While inspecting my front end I discovered that the shop that installed my drop spindles put the steering arm on the upper set of bolt holes. I assumed this was done because when the steering rod was bolted to the (proper) lower set of holes, the tie rod knuckle would hit the rim or it may have been done because the tie rod looks like its parallel to the lower control arm this way. In any event, this improper installation has caused my suspension to be out of whack.
Did My Cheap Wheels Just Get Expensive?
If the tie rod will hit the rim, the simple solution is have less backspace on my rims. The Vision Legend 17x8 wheels have 5.25" of backspace.
Other guys 3rd Gen Nova setups it appears a 17x7 rim with 4.5 inches of backspace would clear the tie rod and the outer fender. Unfortunately Vision doesn't make a 17x7 wheel in this style. So to do this I would have to get 4 new rims. Ouch!
3rd Gen 8" Front Rim Sizes
This Super Chevy article shows a 69 Nova with 2" drop spindles using 17x8 w/ 4.75" back space up front (and 17x9 with 5.75 back space out back).
Modify the Steering Arms? It seems that modifying my steering arms will solve my problem. I only need to pickup about 1/4" to get my tie rod clearance. This could be done by shimming the steering arms out with longer bolts and spacers or by heating and bending the steering arms. Then I could shorten the tie rods by 1/4" (4-5 turns) and we are in business. Time to unbolt the front end and do some work.
Move the Steering Arm Down and In
After removing the wheel, caliper and disc I was able to get to the steering arm bolts. I removed the bolts from the upper position on the spindle and installed new 1/2" x 3" grade 8 bolts in the bottom position. Then I added three washers between the steering arm and spindle to give myself the extra 1/4" of clearance. (I also added 1/2" x 2" bolts to the upper position on the spindle. This is basically overkill as it only holds the dust shield on to the spindle.) I test fit the rim by re-installing the disc, caliper and wheel to verify the 5.25" backspacing actually cleared the tire. It's really close but it clears. I've read you should have 1/2 clearance for tire deflection but my tires are low profile and the tie rod is right at the point where the tire meets the rim so deflection wont be an issue.
I now have the tie rods on the same plane as the lower control arms and have tie rod clearance off the tire.
This setup is in-fact parallel to the plane of the lower control arm pivot and the ball joint.
168800
168801
409novaman
11-05-2019, 08:06 AM
Well it doesn't seem that anyone takes issue with the pictured method of gaining wheel clearance? It looks like a go.
cornfedbill
11-05-2019, 08:29 AM
The washers between the spindle and steering arm will affect your Ackerman steering. Because this is a rear steer chassis, it will increase the Ackerman effect. This is not a bad thing. It may make turn-in a bit better. However, it will affect bump steer because it shortens the total tie rod length.
It's all about compromise.
409novaman
11-05-2019, 01:03 PM
The washers between the spindle and steering arm will affect your Ackerman steering. Because this is a rear steer chassis, it will increase the Ackerman effect. This is not a bad thing. It may make turn-in a bit better. However, it will affect bump steer because it shortens the total tie rod length.
It's all about compromise.
Thank you for the reply.
Is there a correction for the increased bumpsteer, other than the Proforged tall tie rod ends? I'm lost on a correction...
409novaman
11-06-2019, 05:37 PM
So I guess the dream of a sub $1100 tall spindle are out the window.
cornfedbill
11-07-2019, 04:52 AM
Thank you for the reply.
Is there a correction for the increased bumpsteer, other than the Proforged tall tie rod ends? I'm lost on a correction...
There are several options to mitigate bump steer. I would suggest searching this site and the internet. You may want to start here: http://www.pozziracing.com/first_gen_suspension.htm.
One method for changing bump steer that some of us forget is to increase caster. This lowers the outer tie rod end and reduces bump steer.
409novaman
11-07-2019, 09:16 AM
There are several options to mitigate bump steer. I would suggest searching this site and the internet. You may want to start here: http://www.pozziracing.com/first_gen_suspension.htm.
One method for changing bump steer that some of us forget is to increase caster. This lowers the outer tie rod end and reduces bump steer.
Thank you for the reply.
This seems like a solution: https://baer.com/Baer-Tracker-Tie-Rods-3301014.html
Plus all day to get things right.
Kenova
11-07-2019, 06:23 PM
Don't forget about the Gulstrand Mod.
It made a world of difference in my '71 Nova. Even the "old timer" alignment guy was impressed with the caster.
Ken
409novaman
11-08-2019, 03:35 AM
Don't forget about the Gulstrand Mod.
It made a world of difference in my '71 Nova. Even the "old timer" alignment guy was impressed with the caster.
Ken
Thank you for the reply.
I'll never cut the car. I understand the improvement to be gained, I just don't want to cut it.
It will never be raced and with the Speedtech control arms, I'm sure it will have enough caster for the street.
409novaman
12-10-2019, 02:21 AM
Getting my Viking coil-over shocks today, long time saving for these. MCB Matt gave me a good Black Friday price.
I think I'll order some tall ball joints and tall tie-rod ends.
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