Shocks - suggestions needed

[DeafguyC4]

Hello... I'm new here and I have a question about shocks.
i have a 40th anniv C4 and the shocks are shot (and have been for the longest time). I need suggestions on shocks.

I was also considering coil-overs since I hear that people can use them to lower ride height, which would be pretty nice since I want to lower it by just an inch or two.

Or should I just get regular shocks, and what brand would you recommend? I don't race (aside from the occasional "playing around" with friends) or autocross so I need something of great ride quality and comfort.

Thanks

 

[boomdriver]

Hello... I'm new here and I have a question about shocks.
i have a 40th anniv C4 and the shocks are shot (and have been for the longest time). I need suggestions on shocks.

I was also considering coil-overs since I hear that people can use them to lower ride height, which would be pretty nice since I want to lower it by just an inch or two.

Or should I just get regular shocks, and what brand would you recommend? I don't race (aside from the occasional "playing around" with friends) or autocross so I need something of great ride quality and comfort.

Thanks

Welcome to the board !

Well, there is more to it than just shocks....they matter a lot but the shocks are just what dampens the suspension.
The majority of the work is done by the spring. And yes, you CAN adjust the ride height with the transverse spring by raising or lowering the end link tension and adding or moving shims from the mount.
There are a handful of springs for your rear end that control just how much of the impact you will feel. The first 1984 models came with a spring that was about 499 lbs per in in stiffness/return speed. Pretty harsh...Very harsh..
As people complained GM softened the springs to around half that, in the mid to low 200 lbs range. Much much softer.
Now this is where a shock CAN make a difference. If the spring is so hard that it takes rolling thru a bomb crater to make it move, you can stick whatever shock you want on there and it ain't gonna make any difference.
If you have a spring thats soft enough to travel with most impacts, THEN the shocks ability to take the jolt out, becomes valuable.

IMHO Bilsteins are better shocks because they have progressive dampening, meaning the first inch is easy and gets progressively harder as the shock compresses. They are very durable and completely rebuildable. They can be bought or built to your spec and driving style or conditions. They are also close to $100 each......

KYB and most others are closer to $25 each but they are throw aways and they do not offer the sophisticated dampening of the Bilsteins. They are more like a common shock, a HD version thats gas charged.

Shocks need to be matched to the spring and the driver. If you can find out what spring you have now, you can see if that can be improved upon with a different spring thats softer. If thats the case, Bilsteins will make a big difference. If you keep a fairly stiff spring then the gentler ride of the Bilstein is wasted and a less expensive gas shock will be good 'nuff.

Your spring has a code tag on the top of the right side near the end. A small metal tag that will have a 3 letter code that you need to know. ex: NYU or NYR or one of the others.....
NYR is 228 lbs (softest) Most common in 1993
NYU is 326 lbs/inch (moderate)

If you have the NYR now, I'd spend the money of some nice Bilsteins set up for street/daily driver.

 

[DeafguyC4]

Thanks for the post! This information was extremely informative & helpful. I'll take a look at my springs and I'll probably get KYB or some other brand that my father mentioned (he is the mechanic here). My car currently has Bilsteins on it so that's probably the optimal choice of shocks.
thank you

 

[Hib Halverson]

With respect to OE replacement shocks, Bilsteins are a far better choice than KYB.

Typically, shocks last a long time.

How many miles are on your 40th car and how did you determine the shocks are "shot"?

On ride height, coil-overs can certainly make ride-height changes easy, but the cost of a coil-over suspension is high. You can lower the somewhat by taking out the spring mounting shims you find (either one or two per side) in the front and moving all the spring shims in the rear to below the spring. See the service manual for more information on spring shims.

There are also lowering kits available.

I wouldn't go much more than an inch less than stock, unless you want the car to ride poorly. Cars with base springs will bottom easier. When you reduce ride height, you make it even easier to bottom because the suspension has to move less to hit bottom.

 

[DeafguyC4]

133k miles on the car. The shocks just don't work well at all, because every tiny bump sends a shock through the entire body (very stiff) and going over rough/poorly paved roads shakes the car so much, it's beyond uncomfortable and it rattles a lot. The shocks themselves are very old, in fact I suspect they might even be stock.

 

[boomdriver]

133k miles on the car. The shocks just don't work well at all, because every tiny bump sends a shock through the entire body (very stiff) and going over rough/poorly paved roads shakes the car so much, it's beyond uncomfortable and it rattles a lot. The shocks themselves are very old, in fact I suspect they might even be stock.

Corvettes are not like Camerys or Taurus's or Accords......they do not do rough roads....at all. Potholes, speedbumps, old asphalt roads just don't work in a Corvette. Keep trying to drive bad roads and the Corvette will end up eating a hole in your pocket with repairs. They were not designed for that.
If you expect a car that was designed to go very fast doing it safely and not spill your coffee on rough roads, then I am afraid you;ve made an error. Even a $250,00 Bently coupe can't do that.

Not trying to be an a$$hole, but these cars are not designed to be soft and comfortable like the typical passenger car. They were designed to perform, and when taken out of that arena, they do poorly.

I live in a big city where pick up trucks are more common than cars. Its not known if thats because the roads are so crappy and real cars get broken driving the washboard roads or if the hillbillys in charge around here are just too stupid to patch the holes in the streets. Point is, I'd rather ride the bus than destroy my Corvette on the bad roads 'cause the vette is what it is....it ain;t a Jeep and I don;t expect it to be very comfortable anywhere but a smooth flat road.

The KYB's are cheap replacements and the car will NOT get any softer with those less expensive shocks.
The joke is that KYB stands for Kill Your Back.:ugh
Like I was saying....$25 opposed to $100. You really do get what you pay for.

The Bilsteins are yellow in color. If you have some other color, I suspect someone already replaced the shocks with something cheaper. Thats likely the problem. At 18 yrs and 133K....Original Bilsteins would be getting worn about now. Your 40th AE most likely came with Bilsteins, as did most C4 vettes. Only the base car came with a cheaper Delco or GM shock.

 

[DeafguyC4]

Well, I kind of understood that it can't be soft like a luxury car or like a Lincoln town car. but I'm saying that I used to drive over the same type of road and around town and it wouldn't bother me as much as it is now. Thanks for the input though, and it's just gotten progressively worse to the point where I can't stand it unless i'm driving on a road that is brand new and paved. The roads I'm talking about are not even that bad at all, just a little rough. But like I said, the car feels stiff as hell and it definitely needs new shocks.

I do understand now that I'll have to get bilsteins if I want quality shocks for performance unless I'm forced to get KYB shocks.

 

[vetteboy86]

Welcome to the Corvette Action Center!!

My vote is for Bilsteins.

 

[boomdriver]

Well, I kind of understood that it can't be soft like a luxury car or like a Lincoln town car. but I'm saying that I used to drive over the same type of road and around town and it wouldn't bother me as much as it is now. Thanks for the input though, and it's just gotten progressively worse to the point where I can't stand it unless i'm driving on a road that is brand new and paved. The roads I'm talking about are not even that bad at all, just a little rough. But like I said, the car feels stiff as hell and it definitely needs new shocks.

I do understand now that I'll have to get bilsteins if I want quality shocks for performance unless I'm forced to get KYB shocks.

To make my previous statements clear...

Bilsteins can be set up for performance driving...but not unless you request that. ALL Bilsteins have progressive dampening which offers the soft, gentle dampening. Only when the suspension is near bottomed out does the Bilstein get hard or firm. KYB and 99% of all other brands don;t have the progressive dampening making them either too soft thru the entire travel of the suspension, or too hard from the smallest bump thru a speed bump at 45mph.

I have KYB on my rear end right now. I also have a 411 lb/inch rear spring, so it takes being dropped from 10 ft to get my rear suspension to move. Bilsteins are wasted back there with that spring and its stiff rate.
However, on the front where control is needed, wheel stability and where initial impacts are far more appreciated, I have some moderate performance Bilsteins on the stock front spring. When I install a softer rear spring, trust me, I'll have my old rear Bilsteins built and mounted and I can donate the KYB to some poor mustang owner or some other car that never had a chance of handling well...

If you shop around you can probably find the Bilsteins marked down at a vette catalog store or vette shop and get them for $75 each. They are really worth it. If necessary, go buy the cheapest shocks you can find and buy time until you can get the Bilsteins at a good price. They're high, I know. But they are the best thing for a C4 and they keep the stock profile.
Good Luck, I';m sure you'll figure out something.

Be thankful you are'nt shopping for "select-ride' shocks...more like $300 EACH..:ugh

 

[spro2395]

Are the original Bilstein's that came on my 85 rebuildable ? Do you know what the spring codes are for an 85?
Thanks

 

[gmjunkie]

Are the original Bilstein's that came on my 85 rebuildable ? Do you know what the spring codes are for an 85?
Thanks

Ther should be a RPO code tag (Bottom of console lid or in rear compartment behind seats!~!!

Check here for RPO Codes..........
Corvette Action Center | Model Center | C4 | 1985 | 1985 Corvette Production

If there are bilsteins on it there probly rebuildable,But there are places that may have a better price on New!

 

[catbert]

If you are going to stay with Bilsteins, have your OEMs rebuilt.

See the factory website at this webpage: Service for the list of services and prices.

 

[Hib Halverson]

Are the original Bilstein's that came on my 85 rebuildable ? Do you know what the spring codes are for an 85?
Thanks

The OE Bilsteins can be rebuilt. Earlier in this thread, there's a link to rebuild info on Bilstein's web site

Spring codes for 85 are:
BMB, FE7 front
HKX or HMP, base front
NYU, FE7 rear
NYR, base rear

 

[Bronze85]

I just put a set of kyb's on my 85, haven't been able to try them due to the weather. I had who knows how old sensatracs on the car and those things were very easy to compress compared to the kyb's. I would say since you have bilsteins you should replace them as such.

 

[WhalePirot]

Yes, Bilsteins

I not only had my originals rebuilt for my Z51 rough riding Corvette, I had them revalved to Challenge specs and the car is great; better.
than the aftermarket Bilsteins I had tried. The '84 Z51 was billed as the roughest riding Corvette ever sold as a byproduct of the 1 lateral G it could deliver.

I wonder if his car is a Z51, with the stiffer springs. Ride is not ALL about the shocks' stiffness. I find that on performance cars, worn out shocks become first noticeable with handling issues, not ride. Surely, the old 'bounce test' is useless on my Vette!

 

[nelson84]

I rrun the edelbrock IAS shocks on my 84 vette, they work great. My 84 is the Z51 model.