1991rsblue

everytime i hit a nice nasty bump i feel my front glide nicely but my back slams down and hurts my back from the impact. i have everything stock on this thing, except ES sway bar bushings, and remind yourselves that the car has 177,000 miles on it. I'm thinking it could be the springs being original and shot and they are original because they still have the GM sticker on them with part number. i put gabriel shocks on it but that didn't help anything when i did that. what do you guys think? I have money coming for lower control arms and a panhard rod from BMR but which springs to choose from eibach?? thanks again

mrr23

yes it's the springs.

Cruzin Kaz

Yeaper. Springs need to be replaced. Now you could lower the car if you liked.

1991rsblue

i could care less about lowering the car. i just want the car to not bottom out when i hit a speed bump or pothole. if i lower the car will the springs be compressed more for strength or cut to lower it down? i'm looking to get strength not height.

MdFormula350

you need new springs, any new ones will give more strength, with varying heights..

moog makes stock replacement height ones..
eibach makes lowered ones..

Ardels91TA

My springs seem to be worn too. Is there a set of perfomance, progressive rate springs that does NOT lower the car? I would buy Eibachs, but I can't afford to lower the car due to low exhaust and steep driveways to climb up. I want the performance, but not the lower stance. I know part of the performance comes from lower center of gravity, but does anyone have any ideas? thanks

CrazyHawaiian

It could be more than just the springs. I think your rear shocks have alot more to do with it than the springs. My 90 RS used to do the same thing ... everytime I go over a speedbump the front would be ok but the rear would 'dump' and everything would rattle. I replaced the rear shocks with Tokiko Blues and the problem stopped right away. I've never heard of the shocks you mentioned. Maybe try a different brand? Does the rear end of the car sag? Take a measuring tape and measure the distance from the bottom of your ground f/x to the ground on each corner of your car. This way you can see if any of the springs are sagging. If the height is the same then the springs are fine and the rear shocks need to be replaced with something else.

Also with 177k miles on the car I would recommend a full bushings kit. The kit is $130 and will make a HUGE difference in the way the car feels and drives. You might also want to look into a front end rebuild kit (around $300) but its all up to you. The stock suspension components are pretty good, but age and wear can make them feel and perform like crap.

So to fix your problem, I would recommend a new set of rear shocks, and a full poly bushings kit. If you do the work yourself it shouldnt cost more than $250 for everything and you will notice a big difference in the way the car feels and handles.

As for the springs, I dont think they make stock height progressive rate springs. It kind of defeats the purpose of progressive rate if the spring is the stock height. The ride will be nice. The whole idea behind progressive rate is that the spring rate changes depending on how much force is applied on the spring. So progressive rates are good for lowered cars because you can have a softer spring rate when no force is applied but when you take a turn and force is applied, the spring gets stiffer. Its something that they do to improve the ride for lowered cars. To improve your handling and stay at the stock height, you need to find higher rate springs. I dont have any #'s offhand what the stock spring rates are, but finding springs with a higher spring rate will make them stiffer. Going too stiff will ruin the ride, but it is possible to find a mix between a stiffer rate and a nice ride at the stock height. Lowering springs are good because they lower the cars center of gravity but the drawback is that your suspension geometry gets changed (bad!). So staying the stock heights does have its advantages. I would recommend you find some stock height springs with higher spring rates than stock. 1LE springs might be a good choice. And I know TVP is selling 4 sets of specific rate front/rear springs that keep you at the stock height (I think). Contact him.

PF Flyer

... and don't forget, it could just be the rubber 'donut' that goes on top of the spring to isolate the body.

Do you still have the 'jounce' bumpers? (the rubber bumper on the top of the wheelwell above the differential) Is it marked as if it's hitting?

mrr23

the rs springs you have are junk. for some reason all the 90-up rs cars fatigue the springs quickly. here is a tech article i did putting 92 z28 1LE springs into a 92 rs.


http://www.fl-thirdgen.org/frontspringswap.html

now this was for the front. but we put the rears in about 6 months ago. he had the same problem. at first we put new gabriel struts and shocks. took care of it for about 2 months. then he started bottoming out again. springs were just giving out. put the 1LE springs in and now very hard to push the car down by hand. i got him the 1LE springs through perfect circle. or you can get them from MOOG. either way it will solve the problem.


http://www.fl-thirdgen.org/rearswap.htm

here are pic on a rear swap. all you need to do is take the lower part of the shock off. raise the car just in front of the trailing arms. now you will need to pry down some on the rear because the torque arm is still holding the rear up some.

shocks have very little do to with body movement. shocks control the tires. they keep the tire in contact with the road. springs control the body movement.

CrazyHawaiian

Are you sure about that? Remember he's talking about going over bumps or speedbumps, not driving. I had the same problem as him (in my 90 RS) and fixed it with a new set of rear shocks. I am still running the stock springs to this day (tho they will be replaced with weightjack kits when I swap the motor) but I dont have the problem anymore. I think dead shocks in the rear can have alot to do with body movement when you go over speedbumps and stuff. It will cause the rear to feel like it drops and then bottoms out. It feels really bad. Combine it with bad worn out bushings and you can really feel it good when it bottoms out. I know exactly how this guy feels.

EvilCartman

iTrader: (1)

Sounds like worn out shocks to me.

AFreaknGoodTme

I must respectfully disagree with this statement. Shocks control compression and rebound forces as we all know and have everything to do with chassis control and stability. when entering a corner- the front compression and rear rebound come into play, and when exiting a corner the front rebound and rear compression come into play. If these setting are too high or too low in can cause oversteer and understeer problems. Shocks have a major role in chassis control. I must think that maybe you said this only to try and simplify things on a need to know basis, based only on the scinerio above, but just want to clarify for others the importance of shocks.

Low compression or no compression will cause a soft spring to bottom out. High compression will stiffen and slow compression movement also causing deflection to the chassis(A hard ride)

Low rebound or no rebound will cause a tire to bounce like a basketball. High rebound will cause the tire to slow too much coming back down out off the wheel whel and momentarily loose contact with the road.(This is often the cause of tires skipping during braking).

Mrr is correct in telling you your springs are fatigued and should be replaced. They are collasping and the car is hitting the bumpstops.

1991rsblue

alright guys, i would like to thank everyone for the assistance. During regular driving i'm not bouncing around but i do feel a distinct rattle and jolt when i hit a pothole or speedbump. i replaced the shocks with autozone gabriel shocks about a month ago and i didn't even feel a difference. i would like to get kyb or moroe shocks but don't have the mula yet. i was wondering if changing the LCA's and panhard rod would help along with the springs. i will look into the links to see if i can find a nice progressive set but stock hieght. thanks for the help!!!!

mrr23

yes i am sure about that. i run/own a suspension/alignment shop. i deal with this all day long. everyday. www.asbdcnow.com/tredalign springs support the body. the car can still have the correct ride height and still be fatigued enough to allow the body to move up and down. shocks try to slow the movement of the spring down. they do not support the body in any means whatsoever. meaning they do not hold the body up. stock type shocks are made to be loose down and tight up. to make riding comfortable. so when he hits bumps, the axle goes up and the body comes down. the only thing to keep them from colliding are the springs. then the shocks makes resistance on the upward movement (rebound). so again quick to compress and slow to expand.

crazy hawaiian - if you read his post, he replaced the shocks and made no difference. and it is while he's driving. the shocks you got are the reverse of stock type shocks. they have a greater resistance to downward movement and easier upward movement. to assist the spring in the compression stroke and allow less resistance when rebounding.

AFreaknGoodTme - yes i was trying to simplify the situation. but still the spring does more to control body movement than shocks do. if the spring doesn't compress, then the shock does nothing.



http://www.eibach.com/index1.htm

click the performance suspension on the left. then click road-race kit. look at what you get. a set of springs. no shocks. but they say get the sport tuned dampners (shocks).

1LE/WS6 suspension cars if you have been in them ride tight/rough. not because of the shocks. but because of the springs.

brett_sc

I think I am having the same "bottoming out" 1991rsblue was having. I haven't really noticed it over speed bumps, bcuz i go slow, but something bad and loud is definately happening over potholes, bumps on the highway, sounds like tire hitting wheel well. (caused bead leak in tire twice now!)

I am sure my shocks are bad, (left one is covered in it's own oil), so those will be replaced.

I was hoping you guys could help me answer some questions I have about upgrading my suspension.

* what's the difference, other than price, between KYB's gas-a-just and GR 2 shocks/struts? Or rather, whats the best shock/strut for the $$?

* How much better are Eibach's (Pro or Sportline) springs compared to the Moog's?

* How much effect do the Eibach's have on the geometry? and can this compensated for by simply having the car aligned?

All advice and recommendations on parts are greatly respected and appreciated.

Also, I am going w/ 34/24 mm sway bars w/ ES urethane bushings, if this help w/ your recommendations.
Thanks a lot to all in advance

mrr23

well i don't know anything about the kyb's. but i can answer the geometry question.
http://www.fl-thirdgen.org/frontspringswap.html

going from old worn out springs to new 1LE springs, it raised the car about 2 1/2". i put in there what the alignment camber was before the springs and after i installed the springs.

brett_sc

Mrr-

do you think the 1 LE springs are the best ones to get for our cars? I see a lot of people get those or eibachs.

I am looking for a spring that will help me get good traction w/o sacrificing ride quality. Any spring going to do this?

Also, where did you get your 1LE springs? & and what can I expect to pay for 4 of them?

Thanks,
brett

mrr23

which springs to use is dependant on what you want. if you want increased handling w/o lowering the car, then 1LE are the choice. but, if you want to lower the car and handle, then something like the eibach road race is the choice. or another comparable brand. if you want lower and for drag racing, then drag launch springs. i actually got those springs from NAPA. i alled up for a 92 z28 application with the highest spring rate they offer. the actual brand of spring i got was from PERFECT CIRCLE. they also make valve springs. i paid $70 for the pair.

go to www.1le.net they have all the part numbers for 1le parts there.

tamatt27

Man, I'm glad I found this post too. My car does the same thing. What's the web address for Moog? I want the stock ride height. Thanks,

1991rsblue

i like the moog idea of keeping the same ride hieght but i like the idea of firm 1LE springs. the only problem i have is will it make my car too high. i had a friend who had 1LE springs on his V6 car and it actually rose from his stock hieght.

mrr23

the 1LE springs are for v8 cars. for the v6 cars you would need to get stock replacements or if you want to lower, then v6 lowering springs.

Morley

Just check the shocks. Push down on the rear of the car a few times to get it bouncing, stop pushing, it should rebound 2 times max. If it keeps bouncing..replace the shocks. As far as the LCA's and panhard rod, save your money for now. KYB shocks are the best for the money to stiffen up your ride, Gabriel shocks are more for the family sedan than performance cars.

ROUGH RIDER

I HAVE AN 89 FORMULA WITH THE WS-6 SUSPENSION. THE CAR WAS HEADING FOR THE SCRAP YARD WHEN I GOT IT.I REBUILT THE MOTOR,TRANS,FRONT END,JUST TO NAME A FEW THING'S.I'VE PUT NEW MONROE SENSATRACK SHOCKS AND STRUTS.MAC PANARD ROD,AND TRW COILS AND IT STILL RIDES LIKE A FRIEGHT WAGON WHEN YOU HIT ANY KIND OF ROUGH ROAD.IT FEELS LIKE THE REAR IS DOING WHAT EVERYONE ELSE IS TALKING ABOUT BOTTOMING ,BUT ALSO WHEN TURNING GOING OVER UNEVEN SURFACE IT SEEMS TO WOBBLE BACK AND FORTH SIDE TO SIDE IN THE REAR. I GIVE UP I'VE TAKEN IT TO VARIOUS SHOPS AND THEY ALL TELL ME F BODIES RIDE LIKE THIS,THEY CA'NT FIND ANYTHING WRONG.I KNOW THIS IS BULL BECAUSE I HAD A 92 THAT RODE GREAT. IS THERE ANYONE WHO KNOWS A CURE FOR MY BIRD.

tamatt27

I want stock ride height, and, if possible, I want to increase handling. Someone said 1LE springs were the best choice, what makes them better than others? Also, where would I go about getting me a pair of 1LE rear springs? Is there anything special I would need to do? Or would they just fit right in, no problem? Thanks,

mrr23

the shocks are a month old. as soon as he put them he said it made no difference. reread his post. very doubtful he got a bad pair of shocks right out of the box. not saying it doesn't happen.

mrr23

your side to side description tells me it's the panhard and/or trailing arm bushings are worn out. i use the monroe's on my car also. i put the lakewood trailing arms and adjustable panhard rod on and it took out 95% of the side to side movement. the bushings may look good but just worn out.

mrr23

what maeks them the best choice is they are the only ones i know of with increased spring rate w/o lowering the car. these were the cars that were winning showroom stock SCCA races. what i did was call my local parts store and looked up a 92 z28 with the highest spring rate. the ones i got were from PERFECT CIRCLE.

or you can go to www.1le.net and get the part numbers and see if your local dealership can still get them.

they are the same dimension as the stock ones. so they fit in no problem except for doing the work.

www.fl-thirdgen.org/frontspringswap.html here is a tech article on doing the fronts.

Morley

Take a pill. I am capable of reading and understanding what he wrote.

Re-read the last line of my post maybe? Putting the wrong shocks on a car is as bad as having worn out shocks, sometimes worse.

mrr23

i saw where you said gabriels shocks are for the family sedan. also in another post i said that i put a set on the car in the front spring swap that i posted. so it's not the shocks. quit dancing around the shocks as being the culprit.

now this was for the front. but we put the rears in about 6 months ago. he had the same problem. at first we put new gabriel struts and shocks. took care of it for about 2 months. then he started bottoming out again. springs were just giving out. put the 1LE springs in and now very hard to push the car down by hand.

i put this in another of my posts. used the same gabriel shocks. yes there are better shocks out there. ones designed specifically for road racing. but the shocks are not his problem. the 90-92 rs springs are junk from the factory. they just wear out way to fast. i personally think they were using v6 springs in them. but i'm sure that didn't happen.

1991rsblue

thanks for the great advice mrr23. i aprreciate it and i'm going to get new sorings as soon as i get some more money and i think i'm going to get the 1LE springs and cut them a tiny bit to get v6 ride hieght but the V8 1LE compression and stiffness. i'm going to change my shocks to the kyb brand but not until i see a difference in the bottoming out area with my new springs. i'm going to call GM with the part number and get a price on them.

1991rsblue

to answer the question about boncing my rear.....i got it to bounce and stopped and it came up and then settle back to ride hieght. so i don't think my schocks are bad, plus they are only one month old anyways so it would be hard for me to believe they are both bad. the car sits level and my rear doesn't sway or anything just bottoms out and hurts my freaking back with every hard bump.