M3638

iTrader: (1)

1991 Z28, coupe, 350 T5, 20 in Iroc wheels, new regular KYB's installed, and it has the stock springs. I liked the ride height and the suspension performed well until I added about 200 pounds or so of audio equipment. Now the rear end is a little lower which made the front come up just a bit. Also the rear end bottoms out in dips.

I don't want to lower the car, I just want it to not bottom out and adjust back to where it was, in height front and rear, prior to installing the subs and amps. In order to do that, do I get other shocks like the adjustable KYB's or get different springs?

8Mike9

Springs...they control ride height and load...the shocks dampen the ride

plum92_camaro

you could try new stock moog rear springs, but do you research on which ones would be best for your load. If your springs are original they could be sagging.

You might try to install new spring isolators, that can add up to 1/2".

Then theres always weight jacks, and air ride.

Just curious what you put in, I have a hatch full of stereo and dynamat and my ride height is fine with a 26" tire.

M3638

iTrader: (1)

2 JLW6's, JL 500/1, 300/4, and an epicenter. Its all heavy.

M3638

iTrader: (1)

What are spring isolators? Everything that i have seen is for lowering, nothing for stock height that would be a stronger spring.

Ron U.S.M.C.

Spring isolators are a rubber donut that sits on top of the spring so there is no metal to metal contact there.

I carry tools and my stock springs did the same thing.
I installed KYB Gas a Just shocks and MOOG 5665 springs using the isolaters that were already there and this is what I ended up with.
(if any thing with these 5665 springs you might need to ditch the isolators and use heater hose to bring it down a little.)


It did settle in about another 1/2" so its right were I want it.

M3638

iTrader: (1)

Are these the rear shocks you installed?

SlickTrackGod

I would frist recommend you change the spring isolators to new ones just like others here suggested (do not change the springs), then ALSO buy some high pressure gas charged shocks. THe shocks alone will raise the car about a 1/4 to 1/2" over old worn out non-gas charged shocks. This will also help damper the excessive weight and the suspension will not travel as much as it is currently bouncing. You will need this regardless of springs so do it first.

if you replace only springs and keep the old shocks,m the car will still bounce badly and have lots of unwanted suspension travel.

I would suggest koni Yellow monotube shocks.

SlickTrackGod

Spring support the load, they do not control the load. Shocks are what control the load.

I will give an example:

take a spring that is soft with a good quality shock dampering- Lets say the ride height is 25" and you hit a big bump. The car can travel down to 24" and back up to 25.5" and then ocillate until settling back to the static 25".

Now take the same car with crappy shocks and stiff springs. There is no real compression force of the shock to assist the spring from compressing when you hit a bump. The car may staic height sit a 1/4" higher at 25.25", but the bump will compress it down the same if not further if undampered. It will then recoil upward a lot more agressively and contiinue to do so more times then the above combination of old spring new shock. it will go down to 24, and then up to 26 and back and agin a few times more decreasing with each cycle.

Thus, the ride hieght is not controlled by springs because you se the ride height changes more times by the springs then it does with shocks. We are not concerned about a car sitting static parked in a garage, we want what is happening as we drive. The shock controls a more consistent ride height, not the spring.

If you were to take the shocks off the back of anyones car you could probably bounce it enough to grround out anyones car here on these boards. you can NOT ground most of them out if they have good shocks on them

Ron U.S.M.C.

No, they are called " Gas a Just" by KYB .
Heres a link = http://www.kyb.com/products/gas-a-just/

I bought them at Rockauto. = https://www.rockauto.com/catalog/catalog.php

Just enter part # KG5562

Rockauto is offering them at more than 1/2 off the regular price elsewhere.

I first tried the new shocks and they did not raise or support the rear. As a mater of fact the shocks would bottomed out with the old springs or at least hit the bump stops until I installed the new MOOG 5665 Springs.

The 5665 springs with a KYB Gas a Just shocks gave me the nice firm rear I was looking for.

With 200lbs of weight in the rear you might need to install Drag Bags into the new moog 5665 springs to make absolutely sure they don't bottom out over a large bump/etc. There not air shocks .....= http://www.summitracing.com/search/y...51552%2B400054

I'm thinking about putting them in for that reason.

plum92_camaro

Dean, in this particular case, would't it be cheaper and more feasible for him buy moog springs and kyb's to raise his rear ride height?

SlickTrackGod

He's got the weight of an adult riding on his back bumper. he's going to need a much better shock dampering then what a crappy KYB gas-a-just can provide.

M3638

iTrader: (1)

The KYB gas adjust shocks are the ones I have, I had to look and confirm that. This is a lot of good input, I appreciate it. I Think I might get the adjustables and buy new stock height Moog Springs. I'm sure those old springs are done. Thank you

SlickTrackGod

I gaurantee you those isolators are in far worse shape then those springs are. they are less expensive too. I just do not see justifying replacing stock springs with the same stock springs. You may ride a 1/4" higher but will still ground out.

Case in point, I have an old Cadillac ElDorado I drive almost daily (that a lot of people do not know about- It's my undercover car) I regularly stuff enough weight in the truck equivilant to 3 dead bodies. The springs are original from 1985 and with all that abuse they are fine. I change shocks about every 5 years on this car when it starts boucing a lot form excess weight and grounding out. Springs do not wear out like people think they do for some reason. they will loose just barely a bit of height, but they do not loose rate.

ps- yes everyone, I even run koni's on my suga caddy and my Mercedes.

M3638

iTrader: (1)

I'll try that first.

SlickTrackGod

I promise you that you can;t go wrong at least buying those first. They are quick and easy to install, and the original ones can crush and loose up to about 1/2". The rear isolators are thick.

8Mike9

STG, you misunderstood me..

Springs or leafs are made to carry the intended load

M3638

iTrader: (1)

Where are you guys getting your isolator a from? I've checked Napa, Autozone, and Pepboys and I can't find those. I found them for the front but not rears.

Alice89

iTrader: (6)

This is weird; they used to be sold by moog. Or at least that's what I thought. I just got done doing a search and I could not find anything.

Here is the GM part #: 10290379

But those GM ones are $35 each! Not worth it IMO.

You can by them used though:

http://www.ebay.com/itm/1993-2002-Camar-Firebird-TransAm-rear-coil-spring-isolators-/331319064302?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3ACamaro&hash=item4d2427b6ee&vxp=mtr

luvofjah

iTrader: (2)

Moog sells a "CC", Cargo spring for the rear, to help with junk in the trunk... I have them in my car (stereo stuff not in yet, but rides nice (tons of other new / rebuilt stuff)...

Rafael

Ron U.S.M.C.

If he's going to be pulling the stock 23 year old springs to install the new isolators then from my experience, he should spend the $47.79 at Rockauto for a "new set" of springs. Why drop the rear axle and not change them while you have them out ? I did mine because the stock sagging springs were not able to handle the load I have in there and on top of that I plan on having my car for a very, very, long time.

Side note = Replacing the old springs DID bring the car back up to where I wanted it with a full load in the rear.
The old stock springs actually aloud the rear of the car to sag below the front with the same load.