You can see pics of my car in My Garage to see how it sits now. Also, you can see my other mods in my sig. I've been hearing a banging/popping noise in the rear passenger corner, almost up in the fenderwell when I go over any kind of bumps in town. I've decided that my spring isolater has probably either been destroyed or has become dislodged, so while replacing it, I want to replace springs at the same time. I don't really care about ride comfort. I want the best performing spring I can get, without losing any more ground clearance. I normally drive like a sane person, but I'm not at all afraid to drive the car hard. Due to my large oil pan, SFC's, and Spohn torque arm, I do not want my car to sit any lower than it currently does. I also have dual 12" subs in an MDF box with two large amps in the rear well of the car.

With this in mind, do I go with Moog springs for stock ride height, and if so, given the stereo equipment in the back, would I want the progressive rate springs, or the flat rate springs? Or, does it look like my car is already sagging low and putting on stock replacement springs would raise it too high, but some 1" lowering springs would keep it at its current height? Please recommend some part #'s along with some rationale. I don't care how much they cost, and I don't care about ride comfort. This car is driven less than 3000 miles a year. I want the best performing spring I can get, without losing any more ground clearance.

Thanks,
Eric

 

ttt

 

Can't be of any real help, but I'm considering either the Moog IROC style springs that Spohn sells or OEM's from http://www.eatonsprings.com/ Cost here, IIRC, was $300 a set.

JamesC

 

just the rears or both?
cc635 as i've posted in your other thread is good for the rears - especially with the stereo stuff back there.

Fronts you can use 5660, 5662, 5664's. Getting stiffer as the #'s go higher. 5660 is the sport coupe V6 sorta base model style. 5662 is the Z-28 stiff one. 5664 is the ultra stiff S-10 / camaro convertable style one. I have the 5664 and I love it.

 

How high does your car sit with the Moog springs? Do you have any pics? The only reason I'm holding back from getting them instead of lowering springs, is that my car is probably sagging, and I don't want to raise it any higher than it is.

 

there's one, keeping in mind the tall 275/60/R15's out back (28" tire), and the car's on a sloped driveway

https://webdisk.ucalgary.ca/~jmknopp...t,%20may06.jpg

 

Thanks for the pic. That setup looks fine on your car due to your larger tires. I think with stock tires though, it would give a lot of fender gap.

 

hmm, yea, can't say I suppose...

 

Saw your posting and I have similar concerns. I have a 85 Iroc-z that I am replacing the rear springs and purchased the cc635 progressives. I carry no extra weight or stereo gear in the rear.The Moog book at a local auto parts shows only the cc635 as a Iroc only replacement yet Summit Racings web site shows a non-progressive rear spring set mog-5665 as a replacement for the rear. S0, which one should I use? I would like to retain the original ride and height. Thanks,Badman

 

Kind of hard to say. Depending on the year of your 3rd gen, some parts stores will list it as taking a cc635, and some years show a 5665. Not sure which is which, but as we all know, 3rd gens are all pretty similar so...More of an opinion there.

I used the cc635, and I don't have a lot of extra "gear" in the back. In fact, I have no spare tire, pretty much nothing back there - but a long term goal of a big stereo.

I had to make that tough choice a while ago, I think I did a few searches online, and found the cc635 as being more common and popular, and went that route.

You can see my picture there showing my car with the cc635, and no weight in the back. I'm still using the isolators, and like I said, tall tires in the rear. Mwnova has the same rear tire size (not sure about his rear springs), but no rear isolators. I think sofakingdom runs cc635's out back. Those are the only other members that I know their rear spring setup (weird stat to remember eh?).

Some of the real hardcore suspension guys may have something to say about the difference between using a progressive rate spring and a normal rate. I'm guessing a normal rate spring is more predictable in a racing situation, but I don't know about that.

Sorry, i'm not giving you any definitive answers on this topic, but you PM'ed me to answer this thread, so I felt obliged to not ignore you, there's my thoughts

 

I would verify the source of the noise first...it takes more time to jack up the car than it does to pull the rear springs. I would guess your noise has nothing to do with the spring or the isolator.

 

If you can pull the rear springs that quickly, how are you doing it? The isolator is the only thing I can think of that could be banging. It was doing it before my engine swap, so it's nothing in the driveline. I've checked the shocks, sway bars, control arms, panhard bar, torque arm, sfc's and are still welded tight; everything is tight. No slop in the rear end, bearings are fine. The springs are the only things left I can think of, and it is very definitely heard and felt when going over bumps at low speeds just inside of the rear passenger wheel well. It also seems to get slightly better if someone heavy is sitting in the passenger seat. It is definitely a hard metal to metal contact that is hitting a very solid part of the car, because like I said, you can feel it and hear it, and it has kind of a rebound type sound after it happens. This is the only thing I can think it to be. But still, please tell me your easy method of pulling the rear springs. What I thought I'd do is put spring compressors on a spring with the rear end loaded, and then lower the rear end towards the end of the travel of the shocks and swaybar, and then hope somewhere in that lowering, the spring will come out. This way, I wouldn't have to take loose the sway bar and shocks as is suggested in the tech articles.

 

rear springs are super easy to do.
Just jack up the rear of the car as high as you possibly can. Put stands under the frame, let the rear end hang.
If you can't simply pull them out right then, then jack up the pumpkin a few inches, and unbolt your shocks from the rear end tubes. Then lower your rear axle via the jack, until the springs fall out and hit you. You don't need a compressor for this at all. It's a breeze.
oh yea, and maybe unbolt the sway bar. I don't remember if I had do to do this.. Probably.
But yea, it's like 4 bolts, and jacking it up once. It's pretty easy compared to front springs

 

Thanks. Is there any special way the springs have to be seated like the fronts do?

 

No.

JamesC

 

if it's a "cc" spring, the narrower part goes down on the axle, and the wider part goes up onto the body. Otherwise, no.

 

No.

JamesC

 

What's the difference between the cc and the OEM spring in the above regard?

JamesC

 

The cc spr.... wait a sec, you're right, both springs would have to have a narrow part, in order to work with a 3rd gen rear

Nevermind, carry on.

 

Thanks for your reply.