canbaufo

Been reading up on this some but in a way the more I read the more confused I get. I'm just not knowledgeable about suspension. Well here's what I HAVE learned:

- Koni's are pretty much the way to go, but from what I gather they need to be "dual adjustable" so these http://cgi.ebay.com/ebaymotors/KONI-...1%7C240%3A1318
....wouldn't work like that, right? (they say "single adjustable"). Since I have a Pro-Kit I need something that can adjust compression and rebound (need less compression but more rebound since the Eibach's are a stiffer spring, correct?

- Adjustable panhard bar is a must since my car is lowered and likely off center. Can't seem to determine if dual adjustable is worth it or not.

- My car has 52K (94 Z28) and I want everything else to be up to snuff. What all do I have my mechanic friend check and/or replace? I already have poly bushings and ends for the front sway bar. I assume it's time to do the same for the rear sway bar (think I'm keeping the stock sways as they seem to be a good compromise for drag racing and auto-crossing since they're only somewhat rigid). I guess an example would be the A-arm bushings and shock mounts, do I assume they need to be replaced since the car is so old? ...or could it be a waste if it's in good shape?

So the Koni Sport Shocks are the wrong ones, right? They need to be Koni DUAL adjustables but what are those called? Sorry for the ignorance, just never even bothered to research it much until now.

FWIW the car has boxed relocated LCA's with poly bushings, a poly torque arm bushing, boxed/welded SFC's, Eibach Pro-kit. Now I just want to finish the whole suspension up and want to do it all right the first time. I know I need to call Steve Strano but it will be a crapshoot getting ahold of him, so I welcome any advice in the meantime, THANKS!

Bud M

The single adjustables are adjustable for rebound only. Yes, for stiffer springs you want softer comp. and stiffer rebound.

Single vs. double adj phb - the nice thing about double is adustments can be done by loosening the locknuts and turning the bar. Single adj requires removing one end to adjust bar length. But once its set, no difference.

Your car not only has 52K but its 15 yrs old. All of the suspension bushings need inspection. And Sam will likely suggest that those poly/poly LCAs will be less than optimum for handling.

canbaufo

Thanks Bud M. What's wrong with the LCA bushings .... play? So can someone tell me what the exact name of the double adjustable Koni Shock is please (eg "Koni SA" ...or what?). Just taking notes and making a list ....thanks for the info.

Bud M

No, its not a matter of play, its a matter of poly not being compressible. The ends of the LCAs need to allow the axle to "twist", that is have one wheel closer to the body than the other, the way it does when you corner. The stiffness of poly works against the suspension action in this case. You want a more flexible bushing or a rod end here to allow for proper suspension operation.

From the Koni website:

Chevrolet 93-03 Camaro, All Mdls - Sport (Yellow) Double Adjustable

Front 8242 1005SP1 Rebound and compression are externally adjustable

Rear 8242 1006SP1 Rebound and compression are externally adjustable

hope this helps

canbaufo

Thanks for the awesome information, exactly what I need. Hmmmm, so let me guess, the poly bushings on the LCA's are better for drag racing but worse for cornering? I believe the LCA's came with the poly bushings so I assumed it was an optimal set up. So just having a rubber bushing actually makes a big difference in how much the axle can twist? Almost seems like you wouldn't want it to twist. I guess in theory to get what you're saying it's kind of as if rubber bushings in the LCA's allow for more of an "independent suspension type of action" whereas the poly's are going to make it super solid and flat. So when you go around a corner and hit a bump it's more likely to send the whole rear end up and out with the poly's than rubber bushings. If this is true though then aren't poly's better for drag racing? In a way I grasp this and in a way I don't ...I mean you want to corner flat as possible right? Maybe you're saying in the real world where you have bumps in the curves you are better off with rubber so the rear has some give as opposed to the track where you want to stay as flat as possible at all times. lol I don't know what I'm talking about really but I'm just trying to grasp what you're saying. I didn't understand how an adjustable panhard bar could center the rear until I got under the car recently and studied it, then it made sense to me; the higher the ride height the more the body shifts to the left relative to the axle, the lower the height the more it shifts to the right, it's inherent in the design. Sucky thing is is it's never perfect while you're compressing and rebounding but only when you're riding flat. I guess that's one way a four link or similar setup is so much better. I'll have to study the LCA's to see what you mean next time I get under it.

Thanks for the info, btw, I've always noticed annoying "clunking" sounds since the LCA's were installed (along with a host of other things years ago). It's kind of a popping sound from the rear when going slow over sharp bumps, IS THAT THE POLY BUSHINGS in the LCA's ?!?!? ...if so I definitely want rid of them! Any specific type of rubber bushing really good for the LCA's or just a regular old rubber bushing? Mine are the Lakewood box style LCA's and they've been relocated with welded in relo-brackets and they're set about halfway if I remember right (compromise) to reduce wheelhop on launches (seems to have worked in that regard).

Talk all ya want Bud, you seem really sharp about this stuff so I want your take on it. I have one more concern too ...are the stock swaybars a good compromise between drag racing and auto-crossing? If so I want to keep them. Part of it is I don't want to fork out a lot of money on sways and mine are in great condition. The other part is I realize that really stiff sway bars may hurt launches at the track (people often remove their front sway when dragging so I figure a more flexible one is better than a stiff one ...I won't be removing sway bars just to drag race, just not that into it ...I just want the car to be a good compromise between straight line performance and handling.

Thanks again for the info, much appreciated.

Bud M

Well you do want the axle to be able to "twist" but you want to control it with swaybars, not LCA bushing stiffness. If your LCAs use the standard aftermarket poly bushings, the BMR rubber LCA bushings may fit in their place and they will allow more axle rotation than poly.

As far as removing the front bar, I assume they do it just to remove weight. I'm not a drag racer so I don't know. I always recommend a stiffer front bar for one of the first handling mods, the difference is substantial. Strano's front bar is my favorite.

As far as clunking sounds, are you keeping the poly bushings greased? If not, you should be. If your LCAs don't have grease fittings, remove the LCAs and disassemble them and grease all contact surfaces between the LCAs and the bushings with non petroleum grease. I got a big tube from Spohn years ago. BMR has it too.

For autocrossing you will also probably want to move your LCAs to a higher position in your relocation brackets. You want them to be about level.

If you haven't visited FRRAX.com, go prowl around there. Those are the guys who know about autocrossing 4th gens.

canbaufo

Thanks a lot Bud, I appreciate it

canbaufo

Update:

Took it to the mechanic friend and he says the car is tight as hell and showed me the bushings/ball joints, etc with a flashlight and pry bar. He thinks I'm wasting my money if I get new upper mounts, ball joints, A-arm bushings, etc. I was surprised since this is a 15 year old car but it is just under 52K and has been garage kept since new (plus I go WAY out of my way to avoid potholes and bad bumps in general). Looking up at the top of the shocks there was no rust or anything anywhere that I could see.

Do you think in spite of his advice there's anything I should replace (like the upper shosck mounts) that is usually a "given" when installing new shocks? Definitely going with the Koni's ...not a doubt there. Undecided on panhard bar (I see people talking about using "rod ends" instead of bushings on them)? ...still undecided on sway bars but I can do that and the PHB myself later so I'll research more.

Also still undecided on whether or not to get rubber bushings for the LCA's out back, some disagree with you in here ...guess I need to talk to Sam eventually it's just hard with my schedule. After reading up a bit I believe the "clunking sound" from the rear is actually the bottoms of the rear springs not having rubber isolators. I'll address that somehow when we put the shocks on.

One more thing, is there any way the shock should be installed differently due to the car being lowered with the Pro Kit? I know the ext adjustments should be different than stock but beyond that is there anything?

JakeRobb

You sure? You seem pretty knowledgeable on this stuff, but I just want to confirm -- I thought the SAs adjusted rebound and compression together.

bluz28

You definitly want to get away from using regular poly bushing in the LCA's!
IMO, go with rubber, poly-ball, heim-joints, or johnny-joints; all offer great articulation which the rear suspension need to perform properly.
Also poly bushing don't work best for drag racing; they only work best for drag racing(when mounted in the rear LCA's).

And just so you know, the Koni DA's will run you $1400-$1600!

canbaufo

What?!?!? I could swallow $800 - $900 but there's no way I'm forking out $1,500.00 for shocks. So I'm back at square one I guess

....I still don't understand why you'd want more flexible bushings in the LCA's, heck if that's better then why not stick with the flimsy stock LCA's if you want lots of articulation? Not saying I doubt you, but just that I don't "get it". I'm not familiar with the joints you speak of, do they require extensive mods to mount up?

Since a shock needs to be valved properly to work with my Eibach springs and the DA Koni's are ridiculously priced.....what about SA Koni's or Strano's revalved Bilsteins? Can the SA Koni's damp well enough or do you really need both adjustments? ....arghhh, the confusion rollls on ....

lol your statement about drag racing confuses me too, it is or it ISN'T better for drag racing to have poly bushings in the LCA's?

JakeRobb

bluz28

Okay, let me reword this so I don't get myself mixed -up!

It's not that ploy bushings are the best choice for drag racing, poly is just a practical/inexpensive choice that works good in the rear LCA's, since articulation isn't a big LCA requirement for drag racing.

The problem with the factory LCA's is that whole control arm flexes, you just want the flex/articulation in the bushings(mount points).

canbaufo

lol thanks for clearing that up. So "wheelhop" is caused by the flimsy stock LCA's flexing in the middle but "good articulation" can be had by allowing some movement at the bushings so the rubber bushings are better. Now the question is .... HOW MUCH BETTER? Better enough to warrant trashing my poly bushings (which are well used so it's not like I'm just throwing away a new part) and replacing them with new rubber ones? Maybe it will ride a little smoother and quieter with rubber too ....

Actually, this is super simple to understand now that I finally properly visualize it. Imagine the car being lifted off the ground and one LCA is disconnected, with poly bushings on the other LCA that is connected it would hardly even allow the other side of the axle to hang any lower despite being disconnected (in theory). Same thing in the reverse situation, if one wheel is being forced upward by cornering pressure, with poly bushings there is more of a tendency to push the other wheel up as well.

Bud M's original statement of "The ends of the LCAs need to allow the axle to "twist", that is have one wheel closer to the body than the other, the way it does when you corner." should have clarified this for me but for some reason didn't. Well it's nice to finally "get it" but I feel stupid for taking so long lol. OK then I'm definitely getting rubber bushings as long as you all feel it makes a significant difference. Seems like they more so allow the solid rear axle to have somewhat of an independant suspension type of articulation.

thanks for the info

JakeRobb

If I'm understanding all of this correctly, wouldn't stock rubber bushings on stronger aftermarket LCAs be the best solution?