1978 Rear Suspension Upgrade
05-26-2016, 05:59 PM
#1
1978 Rear Suspension Upgrade
What would you all recommend for a rear suspension upgrade to a standard 78'. Was thinking of composite leaf spring and new shocks. Notice half inch lower in back than front with "bouncy" ride.
05-26-2016, 08:46 PM
#2
Composite vs steel I like to ride of the Composite with blisteen HD in the rear vs the stock / steel.
I have the (78) VB&P street / slalom kit front / rear setup. which is a 360 rear and 550 front springs. Blisteen HD all around. This is not a street comfort ride. A lot of people like the ride regardless of the harshness. I have this setup for road racing and not street driving.
You may wish to look at 330 spring for the street.
Then also do a search for which manufactured springs have problems with ride height after installing. There are many threads related to these problems.
05-26-2016, 09:56 PM
#3
How much $$$ do you want to spend.
Composite vs steel I like to ride of the Composite with blisteen HD in the rear vs the stock / steel.
I have the (78) VB&P street / slalom kit front / rear setup. which is a 360 rear and 550 front springs. Blisteen HD all around. This is not a street comfort ride. A lot of people like the ride regardless of the harshness. I have this setup for road racing and not street driving.
You may wish to look at 330 spring for the street.
Then also do a search for which manufactured springs have problems with ride height after installing. There are many threads related to these problems.
Composite vs steel I like to ride of the Composite with blisteen HD in the rear vs the stock / steel.
I have the (78) VB&P street / slalom kit front / rear setup. which is a 360 rear and 550 front springs. Blisteen HD all around. This is not a street comfort ride. A lot of people like the ride regardless of the harshness. I have this setup for road racing and not street driving.
You may wish to look at 330 spring for the street.
Then also do a search for which manufactured springs have problems with ride height after installing. There are many threads related to these problems.
05-26-2016, 11:39 PM
#4
Drifting
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If you're just looking to fix the ride height and ride in the rear, new spring bushes will raise it a surprising amount if yours are flogged, and a good set of new shocks will solve the 'bouncy' feeling. New spring bolt bushes raised the rear of my car well over half an inch - I went to longer bolts to get it back down where I wanted it!
As for other work, if it hasn't been done then new bushes throughout the rear end (trailing arms and strut rods) will make a huge difference, including in the steering! My car still wandered a lot after rebuilding the front suspension and steering until I rebuilt the rear as well. You can space the strut rod bracket down from the diff by ~1/2" to improve (reduce) the roll camber curve. Check the side yoke play in the diff too, as it effects camber.
Then for the front end, again, bringing it up to scratch is important first - new bushes, balljoints, idler arm, tie rods, shocks, assuming like most of these cars it hasn't been done previously/recently. Then you can think about upgrades, Borgeson, different control arms etc.
For the budget you describe, I would try just replacing the spring bushes rather than the spring unless there's an obvious problem with the existing spring. You can normally get a bit of height adjustment out of the bolts too. That will leave you with more budget for good quality shocks and to buy some bushes etc if needed that will make a much bigger improvement in the way the car drives.
As for other work, if it hasn't been done then new bushes throughout the rear end (trailing arms and strut rods) will make a huge difference, including in the steering! My car still wandered a lot after rebuilding the front suspension and steering until I rebuilt the rear as well. You can space the strut rod bracket down from the diff by ~1/2" to improve (reduce) the roll camber curve. Check the side yoke play in the diff too, as it effects camber.
Then for the front end, again, bringing it up to scratch is important first - new bushes, balljoints, idler arm, tie rods, shocks, assuming like most of these cars it hasn't been done previously/recently. Then you can think about upgrades, Borgeson, different control arms etc.
For the budget you describe, I would try just replacing the spring bushes rather than the spring unless there's an obvious problem with the existing spring. You can normally get a bit of height adjustment out of the bolts too. That will leave you with more budget for good quality shocks and to buy some bushes etc if needed that will make a much bigger improvement in the way the car drives.
05-27-2016, 12:40 AM
#5
Race Director
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If you're just looking to fix the ride height and ride in the rear, new spring bushes will raise it a surprising amount if yours are flogged, and a good set of new shocks will solve the 'bouncy' feeling. New spring bolt bushes raised the rear of my car well over half an inch - I went to longer bolts to get it back down where I wanted it!
As for other work, if it hasn't been done then new bushes throughout the rear end (trailing arms and strut rods) will make a huge difference, including in the steering! My car still wandered a lot after rebuilding the front suspension and steering until I rebuilt the rear as well. You can space the strut rod bracket down from the diff by ~1/2" to improve (reduce) the roll camber curve. Check the side yoke play in the diff too, as it effects camber.
Then for the front end, again, bringing it up to scratch is important first - new bushes, balljoints, idler arm, tie rods, shocks, assuming like most of these cars it hasn't been done previously/recently. Then you can think about upgrades, Borgeson, different control arms etc.
For the budget you describe, I would try just replacing the spring bushes rather than the spring unless there's an obvious problem with the existing spring. You can normally get a bit of height adjustment out of the bolts too. That will leave you with more budget for good quality shocks and to buy some bushes etc if needed that will make a much bigger improvement in the way the car drives.
As for other work, if it hasn't been done then new bushes throughout the rear end (trailing arms and strut rods) will make a huge difference, including in the steering! My car still wandered a lot after rebuilding the front suspension and steering until I rebuilt the rear as well. You can space the strut rod bracket down from the diff by ~1/2" to improve (reduce) the roll camber curve. Check the side yoke play in the diff too, as it effects camber.
Then for the front end, again, bringing it up to scratch is important first - new bushes, balljoints, idler arm, tie rods, shocks, assuming like most of these cars it hasn't been done previously/recently. Then you can think about upgrades, Borgeson, different control arms etc.
For the budget you describe, I would try just replacing the spring bushes rather than the spring unless there's an obvious problem with the existing spring. You can normally get a bit of height adjustment out of the bolts too. That will leave you with more budget for good quality shocks and to buy some bushes etc if needed that will make a much bigger improvement in the way the car drives.
05-28-2016, 11:02 AM
#7
Safety Car
Springs and shocks should be treated as a package. People generally select the spring first than then the shock absorber. Shock absorber choces vary based on the spring rate.
Richard Newton
Shocking Information
Richard Newton
Shocking Information
05-28-2016, 11:18 AM
#8
Team Owner
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St. Jude Donor '05
Prefer a somewhat soft (not super soft) spring + a firm shock like KYB for the st. Stiff everythign with no dampening gets real old.
Not saying KYB are best on C3 but they are very firm cheap and will never go bad. Over 20 yrs using them on all my cars/trucks never replaced one.
Not saying KYB are best on C3 but they are very firm cheap and will never go bad. Over 20 yrs using them on all my cars/trucks never replaced one.
Last edited by cv67; 05-28-2016 at 11:18 AM.
05-28-2016, 12:33 PM
#9
Safety Car
I have KYB on my '58. They're great.
KYB is a nice shock for the street.
KYB is a nice shock for the street.
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John Ulrich (05-28-2016)
05-29-2016, 12:44 AM
#10
05-29-2016, 07:10 AM
#11
Drifting
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KYBs are very good shocks for the price. Billys are better though. Given your budget, my choice would depend on how everything else looks. If you need new bushes/balljoints/tierods etc then maybe the difference in cost between KYBs and Bilsteins is better spent there. Also, the Bilstein HDs are a little softer than the Sports and maybe a better choice depending on your goals for the car. I love the Sports on my car though.
06-01-2016, 11:35 PM
#12
KYBs are very good shocks for the price. Billys are better though. Given your budget, my choice would depend on how everything else looks. If you need new bushes/balljoints/tierods etc then maybe the difference in cost between KYBs and Bilsteins is better spent there. Also, the Bilstein HDs are a little softer than the Sports and maybe a better choice depending on your goals for the car. I love the Sports on my car though.
06-02-2016, 12:54 AM
#13
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06-02-2016, 08:56 AM
#14
Drifting
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Doesn't surprise me one bit, hence my suggestion to look it over! I went through the same thing. Pretty big job, but the way the car drives will be transformed when you're done, well worth it. Set a budget, decide what you want out of the car, order the parts to suit and get stuck into it! It's very rewarding when you're done to have the car drive and handle as it ought.
06-02-2016, 09:57 AM
#15
Doesn't surprise me one bit, hence my suggestion to look it over! I went through the same thing. Pretty big job, but the way the car drives will be transformed when you're done, well worth it. Set a budget, decide what you want out of the car, order the parts to suit and get stuck into it! It's very rewarding when you're done to have the car drive and handle as it ought.
06-02-2016, 06:04 PM
#16
Racer
Totally agree...did both the front & rear suspensions.....everything.....including the composite rear spring & Bilsteins all around.
Can't believe it's the same car......amazing handling...what a damn JOY to drive!
Can't believe it's the same car......amazing handling...what a damn JOY to drive!