98 WS6

iTrader: (20)

Hey guys,

I've been over this a few times but I never really got a clear answer.

Ever since I bought my car, the rear end would SLAM hard over bad bumps. I've raised the car a bit since, and it doesn't do it nearly as much. But if I hit a bad bump it'll still slam pretty bad. Will changing my bump stops fix the slamming issue?

Here are my bump stops, I'd say they're shot.




So would this fix my problem? Also when/if I change them should I take the spacer out, or leave them in? I have 275's out back w/ 17" wheels, and the car is lowered on Eibach springs.

Thanks everyone

Major_Lee_Slow

iTrader: (1)

Yes, do replace the bump stops. When you do it, take the aluminum bump stops out. I've had mine out for a few years now and I haven't bottomed out my Koni's yet.

colby72olds

iTrader: (7)

I can't see the pics since I'm at work, but mine was doing the same thing. I checked them out last weekend and there isn't any padding left on them at all! What is the aluminum bumb stops Major Lee, are there other ones besides the cushioned ones?

Sam Strano

iTrader: (41)

The one bumpstop is particularly bad and they should be changed. Your issue is somewhat the springs, mostly the shocks. I'm betting they are KYB Gas-A-Just which just aren't very good. It's not a matter of you hitting the stops, we all do. It's a matter of how hard, fast, and often you hit the stops and shock damping has a lot to do with that (they are after all dampers....). Raising the car helped because you gave the shocks a little more room to damp things, and you gave the spring a little more room to work too.

99Bluz28

iTrader: (35)

Definitely get new bump stops, and when you put the new ones on leave the aluminum spacers off;they're just limiting your suspension travel!

Major_Lee_Slow

iTrader: (1)

All bump stops are designed to be cushions. They help to absorb and dissipate the energy in a manner that is more controlled vs. just hitting a hard stop like the frame. There are two types of rear bump stops on a 4th gen F-Body. The was one p/n which was used on V6's and Z28's which are wider and (if I remember correctly) softer than the ones used on the SS's. The SS's had to be narrower to accommodate the 17x9's. From the pictures, it looks like these were SS bump stops because I don't think that the Z28 stops had an aluminum spacer, but I'm not 100% on that. Sam would know for sure.

98 WS6

iTrader: (20)

I've been through three different kinds of shocks on this car. I bought it with QA1' coilovers all around, thats when it hit the worst. Then i was told that switching back to stock would fix everything, so I got KYB AGX's and Eibach pro kit springs. I literally rolled outta the shop and the rear end slammed. So in the meantime I took Air shocks I had laying around from my last car and put them in the T/A.

So when I get new bumpstops which should I get? The one's for the SS? And I'll take the spacer out.. k!

Sam Strano

iTrader: (41)

You've not been through 3 different kinds of shocks. 3 different brands maybe, but not kinds. All some sort of not great, the AGX's being the best. The air shocks are better because they are supplementing the spring rate (you are running air in them, right?).

You have crappy springs, with not much better shocks, on the worst bumpstops, with the spacers. But then every SS and WS6 has those stops and spacers and not everyone has your complaint..... I ask you, when did this start? My guess is when you put those springs in, or shortly there after.

Major_Lee_Slow

iTrader: (1)

Are you sure you have the Eibach Pro Kit? I ran those for a few years back in 98-2000 and then I switched to the same spring rate Sam sells, lowered the car further and then removed the spacer. I'm still on the original stock bump stops and they look almost brand new.

I think just maybe you have sportlines, not Pro's. If your not sure, you probably should order up a set of Sam's springs and ideally shocks too if you have the money. That should fix your problems.

If money is tight, buy some used Stock springs and DeCarbons for now, then call Sam when you get money.

billyb

iTrader: (15)

1501 Industrial Way North | Toms River, NJ 08755 | Phone: 732.349.2109 | Fax: 732.244.0867


Spacers, 1993-02 Camaro/Firebird Rear-Jounce-Bumper

--------------------------------------------------------------------------------
These aircraft quality aluminum jounce bumper spacers are necessary whenever installing 17" wheels and tires on any 1993-2002 Camaro or Firebird. They are designed to raise the jounce bumper to prevent tire contact with the inner wheel well.

http://www.slponline.com/view_produc...46&BIG=80046-1
read this then decide this is from slp web site .

Sam Strano

iTrader: (41)

Not only are they not necessary, he already has them... and they are taking up working travel. And you don't see everyone with a Z28 without the SS/WS6 specific stops and spacers ripping quarter panels up or tires up, right? I recommend NOT using the spacers.

billyb

iTrader: (15)

do you think that the extra travel that you;ll get will interfere with the tire that slp is saying ?? thanks in advance, and i'm not the least bit doubting you sam billyb.

Major_Lee_Slow

iTrader: (1)

My spacers have been off my car for 3 years, and I run 315's, plus I know I get into the bummers once in a while and I've never ever ever had the wheel/tire contact the fender.

HOWEVER the SS spacers/jounce bumpers are narrower than the Z28 bumpers. And if you let the axle hang, like when the car is on a lift, 17's can/will contact this spacer. My 17x11's even hang on the SS bumpers, with no spacer.

98 WS6

iTrader: (20)

The rear of the car has been slamming since the day I bought it. When I bought it, it had QA1 Coilovers on all four corners. You, Sam, then told me to get LT1 Eibach pro kit springs with the AGX's, and I did, bought them from you. After I installed those, it was better, but the problem still existed.

Yes I am sure. The box they came in said Pro Kit at least. I bought everything from Sam, and he told me to use LT1 pro kit springs with the AGX's, rather than LS1 springs.

ItsNotStock

iTrader: (24)

I don't have the spacers. 315's in the back, and the fenders aren't rolled. I have only rubbed the tire on the fender once and that was due to a giant pothole. I would have given up on the shocks being the problem a long time ago. I'm agreeing with Sam on the springs.

Sam Strano

iTrader: (41)

Now we're getting more clear. LS1 and LT1 Pro-kits are very different. At what setting did you run the AGX's? The higher you run them the more help they should have been, but maybe the cost of ride quality. This is where Koni's are much better than AGX's.

I definitely would not recommend an sort of deCarbon. Maybe the stock springs with the the AGX's... Clearly the setup was better than with the QA1's.

I can't imagine a scenerio where I'd recommend AGX over Koni unless the money had a lot to do with it.

The best ride will be with stock springs... but not not lower. You kind of have to pick your poison here. Lowering the car of course means you have less available travel.

Knowing you have LT1's and not LS1's is a good thing. You need new bumpstops, and I'd recommend Z28 versions vs. SS versions (or Formula vs. WS6 if you are a Pontiac person).

98 WS6

iTrader: (20)

Hm, alright. Yeah i can't afford Koni's. I really aren't that concerned with ride quality and comfort, it's a muscle car, I don't really expect it to feel like a Mercedes. The car hugs the corner's like a beast though so i can't be too disappointed. I turned up the AGX's a lot but it never helped too much.

So, Sam, you recommend getting new bumpstops, and getting the Formula/Z28 one's? Why would you recommend those over the others?

98 WS6

iTrader: (20)

On a side note, anyone know where I can order new ones? I used to have a link but I cannot find it. Thanks!

Major_Lee_Slow

iTrader: (1)

I'd bet good money you can get them thru Sam.

Sam, I'm also interested in hearing why you'd recommend Z28 jounce bumpers over SS. Are they a little softer?

98 WS6, I have to say I'm baffled as to why you'd be bottoming out so often on the LT1 Pro-kit. That's exactly what I ran, and I ran it with the De-Crappins and I didn't have this problem. I do agree with Sam that crappy shocks do a crappy job slowing down the suspension movement, but I'm kinda stuck on this one point you made: You mentioned that it did bottom out pulling out of the shop right after the last go around. Was that more like creeping over a curb or driving fast over a pot hole in the middle of the road?

Do you have the stock spring isolators in place, or are you running the heater hose mod? Do you have a huge stereo in the back or something else really heavy in the trunk, you know, like a dead body or something?

98 WS6

iTrader: (20)

LOL. I laughed at the last comment. I didn't literally bottom out rolling out of the shop, but I was doing, maybe 20/30MPH on the road outta the shop, hit a bump or whatever it was and the rear hit again.

(removed the pic)

Yes there are air in my air shocks too, but I run them at the very minimum allowed because I don't want the rear of my car to be sky high. The only time it hits with the air shocks if it's a really bad bump, but it did hit last week.