SuperPro Bushings back in stock at C&S!!!

[Prez1967]

https://www.corvettepartscenter.com/...on-bushing-kit

I know a bunch of you have been waiting

[Hib Halverson]

The advertisement at that link says:

Better than rubber, and far better than polyurethane.

I visited the "Super Pro Suspension Parts" web site and it says about the material used in the company's bushings:

The base material used by SuperPro is a polyurethane elastomer

and

SuperPro polyurethane suspension bushes are not copies of the OE rubber components. They are specially developed from the ground-up to take advantage of this material?s unique properties. Polyurethane bushes by SuperPro are unique as they are the only polyurethane products fully backed Design-Engineered?Manufac (sic) by a professional research and development program with many years of hands-on experience in the automotive suspension industry.

So..."Prez1967" how can Super Pro bushings be "better than polyurethane if they are, in fact, polyurethane?

My experience with Polyurethane control arm bushings has been that, unless they are graphite-impregnated, at best, they will squeak in cool, damp weather and may squeak all the time. I've even had graphite-inpregnated urethane bushings squeak when driven in cold, wet weather.

For a C4, ZR1 or otherwise, which is a show car, waxer or just a "driver" there is not reason to use anything other than OE rubber or good quality rubber replacements.

Now if you are an aggressive street driver or a track rat, obviously you want control arm bushings with less compliance. In that case, there are three choices.

At the low end of the price range and the ease-of-installation range, you have polyurethane. If you go that route, the only way to go if the C4 is both street and track, is graphite-impregnated urethane in the front control arms.

The second choice would be a track-only option and that is replacing front bushings with metallic control arm bearings and rear bushings with spherical bearings. The cost is, obviously, more than urethane, but you'll have zero compliance at the control arm pivot points. Metallic suspension bearings transmit all road noise and harshness to the chassis and into the interior so, while they can by used on the street, you'd better be ready for a lot of noise and teeth-chattering harshness.

The third choice is the delrin/aluminum composite suspension bearing marketed by Global West Suspension in the front control arms. You get a significant reduction in compliance compared to rubber and an additional slight reduction in compliance compared to urethane. Global's "Del-Alum" parts never squeak because they have lube fittings. The "Del-Alum" also is a suspension bearing not a bushing. Lastly, it has a very slight amount of compliance which mitigates noise and harshness to a certain extent.

With one exception, every car to which I've installed aftermarket control arm "bushings" has been equipped with the Global West Del-Alum. The only exception was a Datsun 510 and a Chevy Beretta I once owned. At the time, Global did not have a Del-Alum design either application. The Del-Alum also has pretty darn good durability as long as they are lubed every so often. I had a set on the '65 Malibu project car I owned from the late-70s until 2012. It's Del-Alums had over 100,000 miles on them with no adverse wear.

With all that said, there are still going to be some C4 owners who will insist on urethane. If that's the case, keep in mind that you can only use polyurethane in the front control arms, the stabilizer bar mounts, the stabilizer bar links, the damper mounts and the rear spring insolators.

Do not use poly in the rear trailing arms or the strut rods because, as the C4 suspension moves, those parts rotate and well as moving vertically. Polyurethane is so stiff that it resists the normal rotation of those parts causing the rear suspension to bind as it nears the ends of its travel. Worse yet, with urethane in the rear arms, the suspension rate is not consistent. Because the more a urethane-bushed rear arm rotates, the more the urethane resists that rotation, the car is less predictable driven at the limit. This is especially true at corner entry and corner exit. Bottom line, in the C4 rear, you need to use either stock rubber or spherical bearings. Neither Urethane nor even the fabled Global West Del-Alum should not be used in C4 rear arms.

[Prez1967]

Originally Posted by Hib Halverson

The advertisement at that link says:I visited the "Super Pro Suspension Parts" web site and it says about the material used in the company's bushings:
and
So..."Prez1967" how can Super Pro bushings be "better than polyurethane if they are, in fact, polyurethane?

My experience with Polyurethane control arm bushings has been that, unless they are graphite-impregnated, at best, they will squeak in cool, damp weather and may squeak all the time. I've even had graphite-inpregnated urethane bushings squeak when driven in cold, wet weather.

For a C4, ZR1 or otherwise, which is a show car, waxer or just a "driver" there is not reason to use anything other than OE rubber or good quality rubber replacements.

Now if you are an aggressive street driver or a track rat, obviously you want control arm bushings with less compliance. In that case, there are three choices.

At the low end of the price range and the ease-of-installation range, you have polyurethane. If you go that route, the only way to go if the C4 is both street and track, is graphite-impregnated urethane in the front control arms.

The second choice would be a track-only option and that is replacing front bushings with metallic control arm bearings and rear bushings with spherical bearings. The cost is, obviously, more than urethane, but you'll have zero compliance at the control arm pivot points. Metallic suspension bearings transmit all road noise and harshness to the chassis and into the interior so, while they can by used on the street, you'd better be ready for a lot of noise and teeth-chattering harshness.

The third choice is the delrin/aluminum composite suspension bearing marketed by Global West Suspension in the front control arms. You get a significant reduction in compliance compared to rubber and an additional slight reduction in compliance compared to urethane. Global's "Del-Alum" parts never squeak because they have lube fittings. The "Del-Alum" also is a suspension bearing not a bushing. Lastly, it has a very slight amount of compliance which mitigates noise and harshness to a certain extent.

With one exception, every car to which I've installed aftermarket control arm "bushings" has been equipped with the Global West Del-Alum. The only exception was a Datsun 510 and a Chevy Beretta I once owned. At the time, Global did not have a Del-Alum design either application. The Del-Alum also has pretty darn good durability as long as they are lubed every so often. I had a set on the '65 Malibu project car I owned from the late-70s until 2012. It's Del-Alums had over 100,000 miles on them with no adverse wear.

With all that said, there are still going to be some C4 owners who will insist on urethane. If that's the case, keep in mind that you can only use polyurethane in the front control arms, the stabilizer bar mounts, the stabilizer bar links, the damper mounts and the rear spring insolators.

Do not use poly in the rear trailing arms or the strut rods because, as the C4 suspension moves, those parts rotate and well as moving vertically. Polyurethane is so stiff that it resists the normal rotation of those parts causing the rear suspension to bind as it nears the ends of its travel. Worse yet, with urethane in the rear arms, the suspension rate is not consistent. Because the more a urethane-bushed rear arm rotates, the more the urethane resists that rotation, the car is less predictable driven at the limit. This is especially true at corner entry and corner exit. Bottom line, in the C4 rear, you need to use either stock rubber or spherical bearings. Neither Urethane nor even the fabled Global West Del-Alum should not be used in C4 rear arms.

I appreciate the write up.

I was considering going full spherical bearings on the suspension as thats what i'm running in my Fox Mustang and used similar in a 996 C2 build a couple years back. I have no issue with driving them on the street but figured since I already have a "track car" I can build this into more of a GT cruiser.

Its my understanding that OEM style rubber bushings are no longer made.

Ive talked to some local owners that have alot of success with these SuperPro bushings and since they have been around alot longer than me, I'll give it a shot. Hard to beat for the price and since I have a press at home, it only costs me $408 IIRC

I really really wanted to go full RideTech with coilovers, arms, bars, etc but that shifts the cars purpose.

[Norwegianmopar]

Originally Posted by Hib Halverson

The advertisement at that link says:I visited the "Super Pro Suspension Parts" web site and it says about the material used in the company's bushings:
and
So..."Prez1967" how can Super Pro bushings be "better than polyurethane if they are, in fact, polyurethane?

My experience with Polyurethane control arm bushings has been that, unless they are graphite-impregnated, at best, they will squeak in cool, damp weather and may squeak all the time. I've even had graphite-inpregnated urethane bushings squeak when driven in cold, wet weather.

For a C4, ZR1 or otherwise, which is a show car, waxer or just a "driver" there is not reason to use anything other than OE rubber or good quality rubber replacements.

Now if you are an aggressive street driver or a track rat, obviously you want control arm bushings with less compliance. In that case, there are three choices.

At the low end of the price range and the ease-of-installation range, you have polyurethane. If you go that route, the only way to go if the C4 is both street and track, is graphite-impregnated urethane in the front control arms.

The second choice would be a track-only option and that is replacing front bushings with metallic control arm bearings and rear bushings with spherical bearings. The cost is, obviously, more than urethane, but you'll have zero compliance at the control arm pivot points. Metallic suspension bearings transmit all road noise and harshness to the chassis and into the interior so, while they can by used on the street, you'd better be ready for a lot of noise and teeth-chattering harshness.

The third choice is the delrin/aluminum composite suspension bearing marketed by Global West Suspension in the front control arms. You get a significant reduction in compliance compared to rubber and an additional slight reduction in compliance compared to urethane. Global's "Del-Alum" parts never squeak because they have lube fittings. The "Del-Alum" also is a suspension bearing not a bushing. Lastly, it has a very slight amount of compliance which mitigates noise and harshness to a certain extent.

With one exception, every car to which I've installed aftermarket control arm "bushings" has been equipped with the Global West Del-Alum. The only exception was a Datsun 510 and a Chevy Beretta I once owned. At the time, Global did not have a Del-Alum design either application. The Del-Alum also has pretty darn good durability as long as they are lubed every so often. I had a set on the '65 Malibu project car I owned from the late-70s until 2012. It's Del-Alums had over 100,000 miles on them with no adverse wear.

With all that said, there are still going to be some C4 owners who will insist on urethane. If that's the case, keep in mind that you can only use polyurethane in the front control arms, the stabilizer bar mounts, the stabilizer bar links, the damper mounts and the rear spring insolators.

Do not use poly in the rear trailing arms or the strut rods because, as the C4 suspension moves, those parts rotate and well as moving vertically. Polyurethane is so stiff that it resists the normal rotation of those parts causing the rear suspension to bind as it nears the ends of its travel. Worse yet, with urethane in the rear arms, the suspension rate is not consistent. Because the more a urethane-bushed rear arm rotates, the more the urethane resists that rotation, the car is less predictable driven at the limit. This is especially true at corner entry and corner exit. Bottom line, in the C4 rear, you need to use either stock rubber or spherical bearings. Neither Urethane nor even the fabled Global West Del-Alum should not be used in C4 rear arms.

Hib,

if I understand you right this kit is not recommended to use?

http://www.bde-systems.com/1984-1996...-complete-kit/

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[Jagdpanzer]

Funny, I noticed the same thing on the main SuperPro site when I first started researching these last summer.
Photo on Corvette Parts Center shows them all except for the batwing.
https://www.corvettepartscenter.com/...on-bushing-kit


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[Jagdpanzer]

Here is their batwing bushing listing
https://www.corvettepartscenter.com/...nt-bushing-set


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[Ccmano]

Thanks Phil. I wonder if you can buy the dog bone bushings alone?
H

[Hib Halverson]

Ok. I stand corrected on SuperPro bushings. When they're used in the rear arms, they must be soft enough to allow the arms to rotate as they move up and down.

[Norwegianmopar]

Here is a good video where the quality is explained.

https://youtu.be/4e4CtEwjOnk

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[Erik]

And they are sold out again. Crap timing, as I'm just about to swap my springs.