...as opposed to the pro-kit? Sportline gives the lower drop. Is it a noticable difference in ride quality from the pro-kit?

 

Not from what I heard and read on this board. Lots of guys run springs that drop the car even more (Jamex, Intrax). Hotchkis is also a 1" drop. I read a lot of favourable comments about the Eibach but no real ride difference between the two.

You can do a search to find out more

 

i have the spotlines on my car and its fairly bumpy but im ok with it after all its not a bmw also i think u have to take into account the type of shocks ur gonna run and also the type of side wall height & tire ur gonna use

 

i have sportlines on my car and dont think it rides much firmer then the stock iroc springs. the drop wasnt much either maybe an inch .....my car has 150,000 miles and stock springs were def sagging. im going with a different spring set up and am going much stiffer. it just depends on what you find acceptable for ride quality.....some people complain about the way a iroc rides stock.....they need to buy a caddy instead of a camaro then..... but i like a FIRM ride im going with spohns coil overs front and rear and will be useing specific rate springs front and rear. so i could care less about ride quality...lol

 

I have them and don't like them. I am switching to the pro kit. The sportlines are to soft. The rear bottoms out all the time. I have bilstein shocks/struts too.

 

The springs aren't soft they just lower the car that much. They're designed by Eibach to use the bumpstops to give you that type of ride. If you read up on them they are "Supposed" to hit the bumpstops. I've got the kit and I can feel it when I run over a dime but I wouldn't give up the handling. If I wanted a Cadillac like ride I'd have bought one.

 

The handling isn't that great. The pro kit spring rates are higher. IMO if you lower the car that much, the spring rates should be higher. and using the bump stops sounds like a **** poor fix. my .02

 

Reading this, I think I'll be grabbing the pro kit for my '87 GTA/'90 firebird "Frankenstein". I love how stiff the ride is with the stock WS-6 package, but going too much stiffer might suck. I still have to drive it to work.

 

i have the pro kit gave me a softer ride way softer and i lost my handling to boy was i pissed so i took out the back springs and stuck my factoy ones back in the back and the car works much better but im not keeping it that way my plan is to buy new 92 z28 springs all the way around

 

DOH! If the pro kit's softer than what the stock WS6 springs are, I'm not going to get that kit at all. I'll either stick with stock, or find something else. Anyone know of a kit that will give a 1" drop, and keep the overall feel of the WS6 springs?

 

im about to put on the sportlines with KYB gr2's struts up front and gas-a-just in the rear(since i live in northern NJ and i have potholes that u can lay in), a shitload of polybushings, all new moog steering components, edelbrock tierod sleeves, UMI adjustable spherical panhard rod, LCA relocation brackets etc.....
i have the spring rates on the sportlines and prokits.... and NO THE WS6 springs are def softer than the prokits/sportlines. i havent seen many kits even come close to the ebach spring rates. stock springs arent even progressive...stock WS6 springs in the 4th gens run max 250-360lbs front and 130-170lbs rear!!! so idk about 3rd gens

"Pro Kit: 714 lb/in linear front 1 inch lower front
109/177 lb/in progressive rear 1 inch lower rear

Sportline: 700 lb/in linear front 1.6 inch lower front
80/137 lb/in progressive rear 1.3 inch lower rear


Eibach says the reason the sportline kit, which is actually lower than the pro kit, is softer is because they use the bumpstops as supplemental spring rate to maintain good ride quality and performance with the lowest drop possible. Hope this helps some of you."

i stole that from another post, ive done alot of research on the springs, and the differance in the rates from the prokit and sportlines are minimal, and the sportlines will out perform the prokit anyday, the spring rates are almost identical except on the rear, and the only way to really hit the bumpstops after trimming would be to basically bottom out or hit one hell of a pot hole which u shouldnt do anyway, most ppl put the sportlines on and never hit the bumpstops. the slightly softer rate will give u a better ride but more performance than the prokit bc its more of a drop and more radical and they didnt want the ride to be crazy stiff. the lower drop over the prokit will lower the center of gravity and give it more cornering capability, with less body roll, also with the sportlines lower drop up front it will give the car that rake look everyone likes, while the prokit like hotchkins lower 1 inch all the way around and most cars keep the stock *** dragging look like the factory, most ppl end up trimming the front coils of the prokit etc to drop the car another 3/8" to get the desired look which will almost place it in the same category as the sportlines...u trim a prokit 3/8" and u will hit the bump stops, also the sportlines softer spring in the rear will help the car squat and get moving quicker in a straight line i believe. springs will help but your strut/shock combo and bushings as well as other performance suspension products will be the determining factor. i love the radical lowered look, most decide on the prokit bc of road conditions and raised driveways etc. if u hit a bumpstop with the sportlines...u shoulda have avoided that dip/bump or w/e with ur original suspension bc ur gona cause damage and ur not driving right. in all the bumstops allow a stiffer ride bc its supplimental use with the spring...and they are only for the the race car enthusiast lol. gotta love the look!!!!

 

you have to match the spring rate with the proper strut. i can not stress this enough. if you take an off the shelf kyb gr2 or something similar and match it with a eibach sportline 2" drop/similar spring or even their 1 1/2" pro-kit drop your going to have a better ride then your 100,000 mile worn out suspension but it's not going to be the ride you could have had. then when those who do this come back here to express how the ride "sucks" it completely changes how others see things and rumors begin.

if you want a good ride with a lowered spring just match the strut/shocks properly. understand that lowering your car that much without moving the center of gravity... for example a drop spindle which completely moves your whole assembly... will cause your car to not ride as comfortable as the factory height but that doesn't mean that it can't ride nice.

do your research and match your parts properly, it's the same as putting the wrong cam in your engine. it's just as important.

 

After running a few spring combos in my TA, I like cut factory rears better than the Eiblows for handling. It rides a little rougher but I dont care. The Eibach rears are just too soft IMO. The fronts seem fine.

 

yea i understand that the struts/shocks are a big deal, i just cant afford 600$ blistens/700$ Koni's right now im hopeing this will get me through, it will be an improvment and i dont autocross or do any track runs its my daily driver, so im hopeing with will do, i just want to be able to out manuver the ricers or some punk that pulls up in a BMW/mercedes AMG. i also bought a poly energy suspension spring spacer for my rear springs. just in case i wanted to raise the rears up to get my height up and maybe stiffen the rears up alil, if there to soft i might find some moogs or something with a higher rate.

i didnt know they made drop spindals for our cars..? where are they sold.

 

they ride like crap , i have 18s , aftermarket suspension parts. its a rought ride . But i do drive a newer dts as a daily and switching between the two is really noticible .

 

I was really surprised how well the stock 3rd gen WS6 package rides. I took a 25 MPH clover leaf ramp at 60, and the tires didn't even squeak! The car sat almost perfectly flat through the whole turn. I felt like I was driving a 'vette. I don't know if it's because all the rubber has been replaced with poly, or if I'm just used to the standard firebird suspension the car used to ride on, but I'm crazy happy with the ride.

 

18inchboyds...wat exactly rides like crap? wat where u referring to....

 

I had the prokit on mine it sucked imo. The car rode ruff and didnt handle any better. I reinstalled the factory BZWs and NNN rears (stock 90 IROC springs). The car corners flat and rides great. The factory spent a lot of time getting the spring rate right. Stiffer is not always better the car has to be setup soft enough to where the tires can follow the road.

The key is the rears The NNL springs ride really ruff compared to a NNN. Try and find a Set of the NNN rears to go with the BZW fronts and i think you will be suprised how well the car rides and handles. Having a softer spring in the rear gives a good ride as well as good handling.

That must be a fun ride bumping off the stops all the time. But it looks cool right.

 

If you are doing springs do shocks (GOOD ones, not KYB or Monroe or Gabriel) and don't do Sportlines. Pro-Kits aren't that great but better than Sportlines.

Also, if you do quality shocks, you will see a greater improvement than just springs. You will see a greater improvement in handling with just KONIs or Bilsteins (no springs) that you will with springs (no shocks).

 

The more I read about eibachs, the more I am disapointed. Spohn recomends the pro kit. There's another member that recomends guldstrand which is cut WS6 springs I think. I haven't been able to get any info on them. Everything on my suspension is good stuff, but unhappy with the springs.

The way I understand it is you can run a softer spring if you have a good shock, like bilsteins or koni's.

But what about stock WS6/1LE springs with good shocks. Also, what does cutting a coil off a stock spring do to the rate? My car is really low now, yes it does look great, but it doesn't handle good enough. I am willing to give up some ride height, but not the factory 4x4 stance. heck no.

 

I've got Sportlines on my car and she rides pretty rough on rough roads, but on the smooth highways it's great.

Tires also make a huge difference as well.
I run 275/40/17 on both sets of my ZR1's, Nitto 555RII's on one set and Nitto 555's on the other. The RII's have such a stiff sidewall that gives you a bone jarring ride, but they stick around the corners like the car is on rails.

 

Oh yeah? I have a 90 IROC with sportlines and I have an STS

I wish my IROC had the electronic adj suspension like the STS.

 

Finding the right springs for these cars is worse than people agreeing on which AFR heads work with SLP headers. Geez

 

Springs, shocks, struts, whatever. Your tires will have the greatest impact on handling and ride. I'd put a rebuilt stock suspension and great tires up against a tricky dicky suspension with radial T/As any day.

 

I agree that tires have a very large impact on the handling, but if the suspension isn't up to snuff to keep the tires planted, they won't make too much of a difference.

 

Wow, I'm starting to reconsider getting Eibachs and KYB's now. I'm about to rebuild my suspension and still haven't ordered my struts or springs yet. Are the Sportlines and gas struts that bad?

 

KYB/Sportlines aren't bad.
Save up and get the Pro-Kit and the Bilstein's. About $700 for all of it if you shop around.

 

Are these what I'm looking for?

http://www.jegs.com/webapp/wcs/store...57238_-1_10075

 

YEP!!!

 

As mentioned, the pro kit is a better performance spring. The spring rates are higher, especially in the back. The sportline kit looks really good, its what I have on my car. I should have listened to spohn and everyone else on the board and went with the pro kit or cut WS6 springs. I got the look I wanted, but am not getting the performance. Can't have everything right?

There is another thread that has the spring rates in it. It's a pretty good thread.

 

I am using sportlines and kyb agx. Street use, a couple of times to the track a year. They work great together. Definitely glad I installed the setup. Easy to adjust.

 

I'm still gonna go with the Pro-Kits. I don't want too far of a drop because some of these driveways and speedbumps make me feel like I'm driving on canyons and mountain ranges.