Camaro5690

iTrader: (1)

I am going to get Eibach springs, But I am curious about the two types they offer. Whats the Difference between Pro Kit, and Sportline, besides height. Which is better? I wanna make sure I get the best performing ones.

online170

Camaroman, if you use the search button, this topic has been covered in HUGE detail. Both give superior performance compared to the factory ones. The sportlines seem to handle slightly better because of the lower center of gravity, but both sets are lacking in the rear springs. Atleast that was the concensus. Also, because the sportlines are so much shorter, they bottom out the rear. Again, this is what ive read, i cant attest to this, and i dont know how hard the car is being driven to bottom them out.

obeymybird

iTrader: (4)

i have the pro kit well had it im going back to my ws6 springs eibach pro kit= big waste of money and time.

85_ZED28

why?

BMmonteSS

becuase they lower the car without increasing spring rate much at all. The result is a car that will hit the bump stops constantly, but continue to ride like stock over small road imperfections.

In a nut shell off the shelf lowering springs are for looks only, and will not increase performance much at all. In some instances they may make the car handle like crap. I wish I had a video of my buddies mustange litterly hopping around a turn on an Auto-x course, the eibach springs were just way too soft for any kind of performance driving.

If you cut your stock springs you can end up with a spring that is slightly stiffer than the eibachs at the same ride height.

fox91rs

springs are hardened steel are they not? so if you cut them and use them wont they shatter at some point, especially when your driving as hard as you do in autocross? just a question not trying to be a ****

Saigon_Bob

iTrader: (2)

I have both sets in two camaros.... the sportlines are lower and come with cool sportline stickers, the others are pretty low too. Neither bottom out going over bumps with new shocks and stuff.

Basically is all about looks and learning to drive a low rider

Saigon_Bob

iTrader: (2)

if you cut them you'll ride like all the civics and other imports that are done wrong. The spring rate gets all Effed up and you'll more than likely have a bouncy ride.

BMmonteSS

Hang on, back the bull **** wagon up here a bit.

Take a look at https://www.thirdgen.org/forums/susp...ates-what.html this thread to see a good discussion on triming stock springs and why eibach's are a wast of your money.

Cutting springs will not make your car ride like a riced out honda with the ebay coilovers set on full drop. The bouncyness you speak of is these cars sitting on the bump stops. The reason it's better to cut your stock springs for small drops is that it increases the spring rate more than the aftermarket springs which will keep you off of the bump stops and get rid of the bouncyness. I'm running over 1000 lb/in springs which is over double the stock spring rate of an RS and 40% more than IROCS and it doesn not "bounce".

When we discuss cutting springs we mean with a rotary cutoff wheel which gets no where near hot enough to mess with temper of the springs. What you are thinking of is when the old timers used to just heat the springs untill the car dropped. This would mess up the temper and the spring would snap in short order.

freestylzz

I don't recommend cutting your stock springs.

I've had the sportlines for 10 years now, and they handle much better than stock springs.

And no, I've never had them bottom out even though they do lower the ride height of the vehicle.

BMmonteSS

Thats because you don't understand what happens when you cut your springs. If you actually take the time to read through the thread I posted you will see that you end up with the same amount of drop with a spring thats a few % stiffer than the eibach's.

You are bottoming out all the time, eibach designed those springs to rely on the bump stops.

freestylzz

I've seen too many cheap people cut there springs, only to eventually buy the proper lowering springs afterwards.

Do it the right way, first.

BMmonteSS

Listen I base my suggestions on FACTS, explain to me why it's the "right" way to buy eibach springs, what makes them better?

Explain to me why a set of springs that have "eibach" stamped on them are some how better than an OEM spring that is the same length and are slightly stiffer. I'm an engineer for a living, I can't go around saying hey do that because I said so. I have to explain my self and provide solid proof for every decision I have to make.

The facts are, cutting 1/2 coil off of a set of moog 5662's will give you a spring that will lower your car 1-1.5" and give you a spring rate of around 713 lb/in.

Those specs look EXACTLY like what a pro kit will give you, if you trim another 1/4 coil off you'll have 750 lb/in which is 7% stiffer than the sport lines and will give you roughly the same drop.

Now step up to the plate and lets talk cold hard facts.

anthony64ss

iTrader: (1)

Eibachs are the most overrated springs on this board period.

They chose asthetic looks over any degree of performance. The spring rates for the drop they give (especially sportlines) is PATHETIC!!! The fact that they would actually design a product to rely on bumpstops for bottoming resistance is ridiculous and dangerous. Once that axle or A arm hits the stop you have a the potential for a virtually infinte spring rate (or at the very least an extremely high one). This results in a loss of handling-especially during going through a turn. If you got these springs for auto-x or HPDE, hang on. Ill take cut moog's everyday for half the price.

Oh yea, be sure to pair them with KYB's everyone raves about

online170

BMonte SS, just out of curiosity, could you please list the front/rear spring rates for OEM springs, Eibachs, and Sportlines?

I was trying to buy a set of springs for my firebird, and figured, hey if i can get performance ones why not? I havent yet bought a pair, for precisely the reason you guys are arguing about. The info i get is all hear say, and so far i have no reason to beleive any of it, except for some of the stuff that Bmonte has said.

In any case, if you read the "pitch" on Eibach springs, they dont really mention any quantifiable info to prove that it increases performance, but it talks plenty about how the car is lowered, and looks so sexy.

I looked and looked, i havent been able to find anyone that sells increased rate springs for these cars, id like to get the pro-kit drop but a higher rate than they offer. Where do you guys get those springs?

Or is the only option for increasing rate, cutting the OEMs?

Saigon_Bob

iTrader: (2)

Well i can see this thread turnign out really ugly so im put my two cents in and that's all.

First i didnt mean to make an argument, all i stated was that my eibachs ride fine and comfortable with no bottoming out to speak of ( the bump stops dont have any marks of wear on them)

2nd i dont know much about engineering cars but i do know that according to what i've read in diff places for a predictable car you want a linear spring rate (stiock type) as opposed to the progressive rate found on eibachs.

that said i come to my 3rd point. We lower tons of cars at work using both lowering springs of diff manufactures and cutting springs. We always remove most of the bump stop of the car depending on how low they go. wat i find is that on cars with DROP SPRINGS they tend to bounce less than cut springs ( ive had the same car do both drop springs and cut springs in the same month to get the right ride height). Now those cheapo slide on "coil-over" spring kits they sell bounce alot, i had a civic with them on there from the time of purchase, loved the stance hated the bounce of blow out shocks. the ride sucked and was a kidney killer
----------
Oh yea and i just forgot to mention.... i use these cars as drivers... not race cars... i dont have much opportunity to push em hard, although one i am know to drift from time to time

5678TA

i disagree.. when i had sportlines on, it was the best handling i ever had.. then i switched back to stock springs for drag and more ground clearance.. the rest of the car was untouched besides the springs.. the stock springs would give a nice roll in turns.. sportlines=flatter than a straight edge.. and this is with upgraded swaybars on both..

91_5.7_TPI

iTrader: (2)

Don't do either. If you don't want to cut your springs, or think you won't be happy with the Eibachs, I'd do some research (or call Sam Strano) and have a custom set made. I think that the Eibach race springs (in any height and spring rate you want) are like $50-$70 a corner. I have the Pro-Kit, and while I like it better than stock, I plan to replace them sometime in the future.

freestylzz

No you listen because you obviously are in la-la land here. You're talking about a set of moog's. Instead of basing your facts on a little internet theory someone wrote up why don't you get your **** in a real shop, start cutting away at a set of oem springs and actually compare the spring rate with those of the eibachs on the machine. I have.

So your engineering degree in sanitation doesn't apply here. Take your garbage elsewhere.

matt_p

New moogs are not old oem springs

91_5.7_TPI

iTrader: (2)

Saigon_Bob

iTrader: (2)

I have Chuck Norris holding up each corner of my car instead of springs and my car can fly.....



the point is that you can do MonteSS theory yourself in an afternoon and find out if its true....

customblackbird

iTrader: (15)

haha this thread is gettin ugly...

i have just recently installed sportlines with new struts and shocks and i did not trim the bump stops at all and i have yet to bottom out even in jersey with potholes that could eat imports. also the car handles like no other id have to say a **** load better then my WS6 springs and they wherent that warn. and if you like that stock *** draggin stance that our cars come with from the factory... than moog springs are for u but if u want higher spring rates without hacking away at them, and a ride that looks like a sportscar like they all should then ebach sportlines are four u. u are comparing moog springs which are not stock springs to ebach....if ur really gona get into it why dont we just throw in air ride technology air bag suspension and hell well even argue about coilovers that will kick the crap outa both with infinite adjustablity. and i only have to say one thing......PROGRESSIVE SPRINGSSSSSSS! moogs are not, eibach are which are designed to give u a softer ride at lower speeds and get stiffer as the riding progresses verses a higher spring rate spring which will ride like **** at low and high speeds.
basically sportlines and prokits like every other lowering kit are designed for better stance and performance versus a stock spring setup and are designed as a bolt IN! intended as a bolt in without modification to the spring and its spring rate. cutting a non progressive spring does not increas spring rate i believe the rate does not change if it is a non progressive spring when cut.
i love the sportlines and are totally worth the 250$ i spent for the look an improved handling, this thing stays straight in 70mph turns when my WS6 couldnt do 55. if its that big a deal shell out the 500$ for coilovers lol i say

online170

Yea youre right this thread is getting ugly. But so did the last one, and the one before that, and the one before that. However, very few of you guys have actually provided convincing evidence. Alot of it is opinions, and alot of the info is not on the same car.

I dont know why someone above said linear rate springs are better than progressive??? That one is beyond me. Progressive is lightyears ahead of linear rates, for precisely the reason custom said. You can have your cake and eat it too.

I also appreciate the response i got from the member who posted his findings about installing both on the same car.

I would still like to know how you guys are finding turns on the street at 70mph, and what angle are these turns???? I think for the folks testing the limits of these products, should slow down a little. For on the streets you should never be able to find the limits of performance springs.

Anyways, it would be great if someone could post some numbers, front and back, of spring rates for eibach, oem, moog, or whatever.

customblackbird

iTrader: (15)

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

customblackbird

iTrader: (15)

stock WS6,1LE V8 (93-2000)
360lb/in front and 130-170lb/in rear
i could only find the front and rear rates of the 4th gens but i kno that the rear spring rate of a WS6 3rd gen was around 105lb/in. not sure about the front but it had to be less than the 4thgens.

i ususally dont find the limits of my products unless i get challenged and that day was a mercedes AMG and i actually drifted between 2 cars in opposite lanes around the curve and im never doin that again.

Camaro5690

iTrader: (1)

well this is interesting, I figure Imma hold off on springs for a while longer. I might just get some oem replacements for now since the ones I have are getting close to shot. I need to do some more research on this before I do anything. Hell if I wasnt in high school with low income Id get some coil overs but I cant afford that.

online170

Thats interesting, i didnt realize the eibach kits were linear in the front....??? Why did they do that?

Anyways, you gotta be more careful on the roads man. I let my brother have a go in my car yesterday, he isnt the most experienced driver, and couldnt handle a drift around a corner. The speed never exceeded 30 km/h (18 mph or so) but ppl generally dont appreciate a big black car revving high, and coming at you spinning with tires screeching. :S NEVER doing that again either.

Camaro5690

iTrader: (1)

how are Vogtland Springs?

http://www.hawksthirdgenparts.com/in...OD&ProdID=1777

BMmonteSS

Wow go away for a weekend and the animals get restless.

There's so much bull **** and misinformation in this thread I don't even know where to start. Normally I would just back out of a **** slinging thread like this, but there are several people who are actually trying to think for themselves in here so I'm going to explain things in great detail so that everyone understands. After you read through this a few times, then post up any rebuttals and provide proof of why you don't think what I'm saying is true. "but...but...but I said so" is NOT going to cut it as a rebuttal.

Linear rate Vs. Progressive Rate:

First you must get through your head that a spring is nothing but a really long rod that has been coiled in to a compact space. If you were to stretch it out strait it would still take the same amount of force to bend it as it does when it's coiled into a spring. Think of this as a cheater bar, the longer the bar the easier it is to bend it, shorten the bar and it gets harder to bend.

Spring rate is a measure of how much force it takes to compress or bend the spring. Most springs are rated in pounds per inch (lb/in), what this means is that it takes say 600 lb to compress or bend the spring 1 inch. In a linear spring this "rate" stays the same, meaning that each inch you compress the spring takes an ADDITIONAL 600 lb's. So compress a 600 lb/in spring 3 inches and you have to exert 1800 lb of force. A progressive spring rate is a rate that rises as you compress the spring, spring companies do this two ways, the cheap way and the way that eibach does it on it's rear springs is to let the coils stack effectively rendering them useless and shortening the amount of spring that is being used. High end race springs use a spring that actually tapers in wire diameter. What this does is progressively increase the rate as it is compressed. So lets say it starts at 105 lb/in at ride height and then goes to 110 at 1", 115 at 2", and 120 at 3" you would have to add each rate for each segment to get your total force. So your total would roughly be 450 lb's to compress this spring 3", now this is rough estimation because the rate is constantly changing as the spring compresses.

Which is better??? That's a loaded question because there are a LOT of factors that play into this, most racing cars (except for Indy cars) use a linear rate spring. The reason for this is that they want to limit body roll as much as possible, so there is no reason to wait for a progressive spring to compress 2-3" to get to the "stiffer" spring rate, they would rather just have the stiffer rate right from the get go. I'm not really versed enough to explain why Indy cars sometimes use progressive springs, those cars are so advanced that the bending in the control arms makes for most of the suspension movement on those cars. Lets just agree they have their reasons, and they most likely don't relate to our 3500 lb road cars.

Now lets discuss why as long as you have a plan and know what you are doing that cutting springs is not a bad thing.

First off the spring rates in question, I'll post links because there is no use rehashing what's already been posted:

Eibach's: https://www.thirdgen.org/forums/susp...t=eibach+rates

Stock / Moog: http://jeffd.50megs.com/Moog_Spring_Page.htm

Lets first take a look at bump stops:

You'll notice in the Eibach thread that the manufacturer themselves admit to relying on the bump stops. If you take some time to look at your bump stop you'll see that it's tapered. What this does is makes the bump stop progressive, it too has a rate just like your spring does. The stock bump stop might start out at about 700 lb/in but quickly goes much higher (think 2500-3500 lb/in) in a matter of 1" of suspension travel. GM was smart about this as they knew that if they used a short, hard stop that customers would complain when they eventually bottom their cars. Most people can't even tell when they are on the stops. It's only when you really slam the a-arm into the stops do you get that sickening feeling in your kidneys. I'll guarantee that their isn't a thirdgen in existence that doesn't have the rust rubbed off the chassis from the bump stop. The problem is that if you don't absorb enough of the bump with the spring and shock that the bump stop has to make up for it, this is where after market spring companies get into trouble. With only 2" of suspension travel left after lowering and a spring that isn't stiff enough a LOT of the bump force gets transmitted into the bump stop. Exactly how much is too much is what we should be discussing.

Lets take a look at how to calculate spring rate, that way we can actually correlate a certain spring rate with how a car rides.

In this thread I discuss the formula and how to use it: https://www.thirdgen.org/forums/susp...ates-what.html

I'll rehash it here for quick reference:
I go over how to calculate your spring rate in https://www.thirdgen.org/forums/su...g+rate+formula (Thinking about taking a coil off my springs!?) thread. Using the formula in that thread and assuming that your stock springs are 650 lb/in I did a little math and figured out what your spring rate would be by trimming the stock springs.

1/2 coil cut = 713 lb/in 9% stiffer
3/4 coil cut = 750 lb/in 14% stiffer
1 coil cut = 791 lb/in 18% stiffer
1.5 coil cut = 887 lb/in 27% stiffer
2 coil cut = 1010 lb/in 36% stiffer


As you can see in that thread that stock replacement moog spring gains spring rate quickly as you shorten it. F-bodies are different that most cars as they have a fairly high spring rate from the factory. This is why cutting springs has gained such a bad name, as other cars have much softer spring rates (250-350 lb/in). So cutting them does not get the spring rate up near high enough to keep them off the bump stops. This gives you the Honda bouncing over the man hole effect as the car bounces on the bump stops and the shocks are too soft to dampen the violent chassis movement caused by the 2500-3500 lb/in spring rates of the bump stops.

Now lets look at spring rate Vs. ride height, can we agree that the lower the car is the stiffer the spring needs to be to keep from relying on the bump stop too much? With that assumption, we know that cutting 1/2 coil will most likely lower your car ~1" many people have verified this. This leaves us with a spring rate of 714 lb/in, which so happens to be the same rate as the eibach's. This in my book is borderline too soft for the drop, but it does work and will be fine for most people who aren't hardcore racers. Now step up to the sport lines and you see they actually SOFTEN the spring rate with another .75-1" drop on top of the pro-lines. Now we are getting really slim on suspension travel and eibach wants to run an even softer spring rate, this in my experience is the problem to watch out for. Sure the suspension will still soak up small expansion joints and bumps, but what happens when you are leaned over on an exit ramp and you hit a pot hole? The a-arm will smack into the bump stop, send the spring rate sky high resulting in snap oversteer or understeer. The scary part is this is actually pretty easy to do at normal public highway speeds. This wouldn't even be an option on a serious race car. This is where cutting your stock springs is better, but in reality not enough. Cutting 3/4 of a coil off will give you a rate of 750 lb/in which is higher than eibach's but not enough in my book. If you are going to be that low I believe you need something in the 850-900 range.

In conclusion, it's a trade off when lowering. You have to seriously evaluate your goals for lowering, for a small 1-1.5" drop there is nothing wrong with cutting your stock springs, in fact your not gaining anything but 5 minutes of your time with the eibach's. When you go lower than this, the stock springs can be made to work and are better than the eibach's but may not be the best solution. The price of aftermarket circle track springs makes it VERY practical to grab some springs and trim them to your desired ride height and rate, they even cost less than a set of off the shelf eibach's. For an even cheaper solution you can either fabricate or buy a set of weight jacks and then trim cheap 30$ a piece moog springs into what ever rate you want and set your ride height with the weight jacks.


All of this information is based off of the following books:

"How to make your car handle" by Herb Adams (Good light read for the beginner)
"Tune to Win"
"Engineer to Win"
"Prepare to Win" All three written by Carroll Smith, this man built the Indy cars of the 60's and 70's that Mario Andretti was made famous in and is an absolute necessity for any gear head that wants to dive deeper into vehicle dynamics.

Of course if you want to really learn about how things work, get an engineering degree. I'm not trying to sound boastful, but I learned a LOT in 4 years that allows me to think for myself and analyze everything in a scientific way that weeds out all the BS that is so prevalent in today's aftermarket parts market.

online170

Bmonte, thanks for posting all that stuff. I appreciate all this info is not quick and easy to type up, let alone back up, and justify, as well as make easy to understand.

In any case, im trying to get my head around some of the info youve posted, and i still have some questions.

1) First off, youve mentioned several times that cutting the spring will increase the spring rate. Why/ How??? Was looking at that formula, and i saw the formula, where the number of coils, is the denominator in the figure. So as that number gets smaller, so does the product below, which makes the over all spring rate higher. Thats fine, just cant get my head around it logically?

Youve said that in a linear spring, as the spring compresses, the rates add up, so how does it become a higher rate when one coil is chopped off? Near as i can figure, the best way i can explain it, (but i dont know is true) is you said, a coiled wire has the same "stiffness" as if the wire were straight. That being said, ill use the analogy of breaking a stick/branch. When the stick is long, its alot easier to break it into two peices by cracking it over ur knee, but as it gets smaller, its harder and harder to break. Is that the right idea?

2) Secondly, youve mentioned several times, that 1/2 coil will result in a near 10% increase in rate, and roughly 1-1.5 drop. Now is this accurate for v8 cars? and is this accurate for BOTH front and rear? I realize that the front and rear are obviously different weights, but the springs are also differently shaped. Basically i dont wanna cut 1/2 a coil off, and find out my front and rear dropped unevenly.

3) Final question, youve mentioned that heat is not your freind when cutting springs. But is there a correct way to cut? I will probably be using a grinder with a cut-off wheel. Those things get red hot, but ill take brakes. However, is there a certain angle that i need to cut at? Or just perpendicular to the the wire direction is good?




Yea this thread was gettin ugly, but theres some good stuff in here

BMmonteSS

Good questions, shows your thinkin!

1: You've got the right idea with the stick analogy, basically it's easier to bend a long wire than a short one. The spring rate is just a way to quantify this.

2:This is fairly accurate for the moog 5662's which are factory IROC springs. The F-41 package and base model springs will vary, this is why it's good to calculate your final spring rate and decide if it's going to be enough. I've been ignoring the rear springs in this conversation because it would clutter things up a bit and make things more confusing than they already are. I'll do the math for the rear springs tomarrow and post that up.

3: You'll never get enough heat in the spring with a grinding disk. If you're good you can even use a torch. You just won't get enough heat in the spring to alter the heat treatment properties.

91_5.7_TPI

iTrader: (2)

I've got a set of stock WS6 springs laying around... are they close to the 5662's? I might just have to cut some on them and see what it gets me. Probably be softer than the Eibachs though, considering their age.

BMmonteSS

They should be 5662's, get the wire diamter, overall length and number of active coils and we can find out for sure.

Camaro5690

iTrader: (1)

Ok now I have another question, what do you recommend for cutting springs? I dont have many tools at my disposal so Im very limited in what I can do to my own car. Ive also had people mention to me that maybe I could find a heavier car with the same spring width and cut them to the right length, because I think that heavier cars should have a higher spring rate. Correct me if Im wrong, which I could be very easily.

BMmonteSS

If you look at the moog spring chart I posted you'll see that the 5662's are the second stiffest spring GM ever used. The stiffest were used on convertable IROCS and are only a few lb/in stiffer. You can use anything to cut the spring, air powered cut off wheel, sawz all, hack saw (no fun) or my favorite a thin cut off wheel in an electric grinder, it only takes a few seconds this way.

online170

Bmonte, you missed my last question. Is there an angle to cut the springs? Ie, perpendicular to wire direction? or 45 degrees like a plant? or in a V????

fox91rs

bmmontess thank you for clearing up my question on the fact of them shattering and all sorts of other good information, that will definatly come in handy.

but would you be able to clearify if i were to autocross my vehicle would i run into the problem of them shattering under so much stress

BMmonteSS

Just cut the spring off square, pay attention to the fact that one end of the spring is ground flat and goes on the chassis side, while the "open" end that has not been ground goes on the A-arm side.


Fox, I'm not sure why you're worried about shattering your springs. It's just not possible unless the spring is very very old or has been heated over a significant portion of it's length. The old timers would just heat the springs untill the springs sagged to lower the car, this would turn over half the spring cherry red. This is the type of heat you need to ruin the temper of the spring.

fox91rs

i just heard bad things, but im glad i asked because this thread definatly cleared things up for me and obviously i have been missinformed in my quest to get my car nice and low and still have the stiffness i desire. thanks again

Camaro5690

iTrader: (1)

so I should go with moog 5664s? the chart says they are the stiffest

BMmonteSS

Yes those springs are slightly stiffer than the 5662's and would be a better spring if max performance is your goal.


I'm not one to gloat but it's kinda funny how all the bad-***'s on the board tend to scatter once some tech is brought to the table.

85MikeTPI

iTrader: (2)

There's no right or wrong answer to this, as there's no single spring that
will be the best in or for every situation. A stiff spring will be harsh, and
may induce understeer. Depends on weight balance, struts/shocks, and
sways/etc.

BMmonteSS

EXACTLY!!!!! This is why I'm so against eiback and most lowering springs, they are not good for anything other than lowering the car. They are too soft and actually ride worse because they constantly hit the bump stops. Since they are too soft they aren't any good for handling either.

My arguement is that in order to run lower than stock you HAVE to run a higher spring rate. No way around this fact, if you have less suspension travel you need to have a stiffer spring.

85MikeTPI

iTrader: (2)

I'm not bashing Eibach or any other Mfg., just pointing out that just
about everything has trade-offs. The Eibach kit is just that, an engineered
kit that tries to accomplish it's goals (lowering) and in the widest audience
of different cars and safely. I don't think they tout the kit as "performance"
other than saying the lower stance will implicitly help cornering. The Pro
kit has very nice rear spring specs, and cutting rear springs is a little more
difficult than fronts. In order for Eibach to build a complete kit, they have
to make sure they don't put any customers into an unsafe understeer
condition, while keep the majority of cars off the bump stops in 99% of
driving conditions..

For most folks, they fit into the window that the pro-kit is designed for,
and will work for them right out of the box..
For others looking for lowering AND performance cornering,
using the rears from the pro-kit along with some cut moog's would be a
better choice. Tie it all together with scaling the car, track testing your
shocks/tires along with some various swaybar sizes for fine-tuning, and
you can have a nice performance corner-carver (sic) in a weekend.. :-p

Just saying Eibachs are junk isn't really fair to the Eibach engineers that
work under all the Mfg/Marketing/Warranty/Legal constraints..

mike

BMmonteSS

That's just it, eibach themselfs say they "engineered" their springs to use the bump stops under normal driving conditions.

The PRO kit does have stiffer than stock rear spring rate, the downside of this is that it will loosen the car up a good bit. The goal if designing for lemmings is to make the car understeer at all costs, thats actually the "safe" way of designing a suspension system. It's un-safe to make a car loose, johny-q public can't even begin to understand whats going on when the back end of their car passes them up let alone react enough to catch it.

Then with the sport line springs they lower the car even further and lower the rear spring rate which will just lead to more bottoming.

What I have a beef with is that there doesn't seem to be any thought out process to how eibach is lowering these cars. It seem almost like they just picked out the cheapest wire sizes and wound them into a spring.

I promise to try and get a set of F-body rear springs and do the math to show what the spring rate will be when you cut them. It's been a busy week. I should really just start providing "pre-cut" springs to the masses, I'll have to paint them some pretty purple color and come up with a cool name for them, but they should sell like hot cakes.

91_5.7_TPI

iTrader: (2)

Does anyone know what they number of active coils is in the Pro-Kit (front and rear)? I am trying to figure what the spring rate would be if I cut about a half a coil off them. Thanks!

Kandied91z

iTrader: (7)

Camaro5690 it's all about matching up the spring rate with the right shock/strut combo. if you choose the pro-kit go with the right setup. i myself went with the bilstein hd's, koni yellow is also great with these. great combination. if you go with the sportlines go with the bilstein sports or koni orange.

if you do get these springs do not get kyb's... your car will bounce with either one for various reasons but the kyb's aren't valved for the drop and literally wear out within several thousand miles. if you can't afford a nice strut/shock combo go with the cheapest strut/shocks you can buy and save up. you'll do yourself a favor in the end and won't end up removing everything because you bought a improperly valved product for your current application.

in the end with the springs i'd read up and go with what you can get the best price with the right weight and rate. if you aren't on a auto-x course you really don't even need to worry about these aspects. just pair things up properly.

good luck.

online170

Why not??? Im sure no one would mind. Youd have your critics, but ill pay the shipping on your first trial set. Use them for a few years, and provide you a detailed analyses of long term use, for your waranty puposes.

Formulabruce

I have a 92 Z Convertible ( red on red leather) Loaded. strut towers, mounts all good, brand new stock 235 tires and tires sit up inside front fender well slightly. Hits alot on airdam. should I assume since an IROC wasnt made that year , the car would have come with the Moog 5664? I would love a couple inches back ( UP) yeah up, I just want to cruise and a good ride wouldnt hurt, stiff isnt what I want but I need it up some. Leaning toward the 5664 unless someone has a better stock Idea. I have been told the verts were lower but I attributed it to the shorter tires, mine is too low. Thanks for all your brain work guys