V8Rumble

iTrader: (2)

Hey all, this should be easy if there's someone out there who has this info. I've done a search, & it appears that the spring rates for the WS-6 suspension on my GTA are probably 548 on the front, & 204 on the rear. Can anyone confirm that??

I'm asking because I'm looking at getting replacement springs that I can trim a bit in order to maintain the correct rate, but lower the car a bit in front. I really like the way it rides now, so I'm looking to maintain that (as much as possible), I just really dislike the fender gap, & I think that a bit of a "rake" from front to back will also help me in my efforts on the Bonneville salt.

Also, can anyone tell me the length of our springs? If I could get confirmation of the spring rates, & the length, I'd be just about set.

Thanks guys.
----------
One more thing (this may help some of you who have been thinking about getting Eibachs or something similar) - in the course of my research, I've found that our cars apparently share the same types of springs with the G-body platform, which is frequently used in circle-track racing. So, if you were to find a speed shop that sells to circle-track racers for a good price, you might just be able to get exactly what you need, without "settling for" the sub-optimal characteristics (progressive spring rate, bottoming out, etc.) of some of the popular aftermarket lowering springs, & save money on top of that!

I hope this helps someone...

customblackbird

iTrader: (15)

didnt think they where that high... i know the rears where around 105lbs. the new 4th gen WS6 springs wherent even in the 500's i think they were around 400lbs, i did a post on them when i compared them to the sportlines/prokits. i had the WS6 on my 87 formula 350tpi and i thought it handled well... but it looked horrible with the fender gap, once i installed the sportlines, i laugh at what my car did handle like, i love the sportlines. i could pull on mercedes AMG's/bmws with the WS6's now its even scarier...

i posted the spring rates on a thread...do a search in the this forum section.

sportlines are 700lbs front and 130 rear, progressive rear springs 1.75" drop front and 1.3" drop rear.=raked look=sexy
prokits are high 600's and 150-170 rear, progressive rear springs, 1" drop front and rear=no raked look

V8Rumble

iTrader: (2)

OK, I'll post a "somewhat modified" question - I climbed under the car, & saw the tags on the springs, so I can now confirm that I have 'BZX' springs. Does anyone know the rate for those???

Thanks all.

V8Rumble

iTrader: (2)

OK, well, I've seen a number of posts where the 548 lb/in rate was mentioned, this post is just one of 'em. I'm getting ready to buy my Konis, & I'd sure like to be "in the ballpark" when I buy the new springs...

Also, I'm still not sure of the length - anyone know if 10" is about right??

ws6transam

I suspect that different year's WS6 suspension settings had different spring rates. I don't think you can simply call it the "WS6" spring. For instance, I am pretty sure that you'll find that the 1983/1984 WS6 springs are much higher in spring rate than 1985/1986 suspensions, and that 1987-1992 WS6 is softer still... However correspondingly, you will find that over the years, GM reduced WS6 spring rates, and INCREASED the antiroll bar diameters, as the WS6 front antiroll bar grew from 32mm to 34 mm and finally to 36 mm.

Tell you what: Next time I pull my springs out, I'll sit on it and see how much compression I get!

V8Rumble

iTrader: (2)

Hey, thanks for the response.

Interesting - without having devoted any thought to it, I would've thought it would have been the reverse of that, given the fact that earlier cars seem to be noticeably lighter. OTOH though, I have noticed that the sway bar diameters increased over the years...

Heh - no need to do anything quite so drastic! I've found someone local to me who has a business geared toward suspension setups - apparently he even has a device that can measure a spring's characteristics during both the compression & rebound phases, & plot them on a graph. If I can't get a decent answer in this thread, I might just pull my springs & take 'em to him. That way I can not only know the rate of my current springs, but get good, solid advice on lowering the car with a minimum of potential side-effects.

BTW - further searching showed that the BZX springs could also be 611 lb/in... Just when you think you have it nailed down...

Tidbit

600lbs on a V8 car you had better have a free height spring length of at least 13 1/2 inches- and that will be a low car. I have 800+ lbs on the front of a V6 and the free height is 12 inch and I sit very low with a fender lip of 24 3/4 inch off the ground.



https://www.thirdgen.org/forums/atta...g-install1.jpg

I 'think' the factory spring free heights are in the 14-15 inch range on a typical aprox 550 lb rate spring- and are a bitch to get in and out of there.

ws6transam

No, it's the result of two different philosophies of what it takes to get a car to handle. Heavy springs will help keep a car flat in the corners on a race track with a given antiroll bar. If you soften the spring rate, you must increase the size of the antiroll bar to regain the flat cornering response. GM took a page from the Herb Adams chassis handling department and softened their springs, and increased their antiroll bar diameter to yield a great handling suspension that didn't beat the spare change out of your pockets on every bump. About the harshest riding thirdgen ever offered was the 1984 15th anniversary Trans Am: They used the heavy spring rates, jumped the antiroll bar diameter to (IIIRC) 34 mm, then placed white painted high-tech turbo 16 x 8 wheels onto the chassis. It was a kidney buster, but did great on smooth tracks. It's rumored to be a hop-skipper when you hit bumps in transitions, though. GM came through in '85 and tweaked the WS6 suspension package to work better with those 16 x 8 high-tech turbo wheels that sold so well.

82CrossFire Z28

iTrader: (1)

From the 1982 Camaro Factory Assembly Manual: Part Number 14029398, Code BZX, Spring Rate = 96 N/MM or 548.6 LBS/in. These were only used on Z28 suspensions in 1982 for the Camaros. Two other BX? and three other BZ? springs were also used on the Z28s. All had a 548.6 LBS/in spring rate. These were all front springs. The rear springs for the 82 Z28 all had a spring rate of 32 N/mm or 188.9 LBS/in.

If GM did not change the part number for a spring code, then I would expect that the spring rate would stay the same over the years. However, I do not know that for a fact.

I also don't know what the uncompressed height of the BZX spring is.

I have BZW springs on the front of my 82 Z28.

Hope this helps .......

Dave

Jay

iTrader: (2)

Here are a few things I have read and come across.


there are several listed spring "load rates" for any given year. This is broken down to generally 2 or more categories depending on suspension.

Certain cars ( IROCs GTAs ) are claimed to be approx 1" lower ride height than standard.

there is no real difference in WS6 vs IROC suspension as the same parts are found on both

It seems to be the general consensus that the upgraded suspension level for a given year has a stiffer rate than the standard.
The parts catalogs list the differing levels with codes ( BZZ, BZX, BZW etc etc ) in each level and corresponding part numbers according to spring "load rate" highest to lowest.
This would seem to indicate varying spring rates.
I have seen it posted that the springs are chosen to keep cars at a consistant ride height with each other based on weight ( ie. what options are added to the car. )

To this end, 1LE spings are in the same category as BZX,BZW springs, but lower on the load rate scale.. which would fall in line with cars with less options getting softer rate springs.

It would seem to me that given stock applications, a heavier car would have higer load rate springs to keep the car at the same ride height as one with less options and lower rate springs. Now would this make them drive, handle and ride similar?
So that would make me think that putting higher load rate springs into a car with less options ( and less weight ) would actually increase the ride height.


Would be interesting to see the uncompressed height of various springs vs the rates.

I know that when GM starts eliminating parts and consolidating, as in "part number such and such now = to new one" that doesn't make them an exact replacement to the previous.
I bought rear springs and tried to get an NNL version, but the part number along with every other one in that category had updated to a 4th gen spring. The new spring had a visibly higher uncompressed spring height, and noticably softer rater compared to the old NNL springs I had.

Jay

iTrader: (2)

According to my GM parts catalog the same springs, with same part numbers are listed for just about every year 82-89. For instance. The 82 has the BZX spring listed as 3rd highest "load rate". In 87 my IROC was equipped with the same spring. It also has the 34MM solid bar which is the stiffest bar available, higher than the 36MM hollow, according to the catalog.

ws6transam

Well, I've been wrong before...
However in the 1984 (updated in 1989) book by Richard Carlyon, "Trans Am" (ISBN 1-85361-111-5 publ. by Chevprime Limited, in London) he states:

"The Days were undeniably ending, however, when a sports car would be widely forgiven for constantly jarring its drivers spine. So in 1985 the top Trans Am's spring rates were softened a little in pursuit of a more compliant ride. To counteract any increase in body roll, the front stabilizer bars were beefed up from 32 to 34 millimeters, the rears having recently been increased from 23 to 25 millimeters. As intended, this allowed for better bump absorption without detracting from coornering ability."

Now so far, I've only found one technical error in his book, but perhaps this is the second one?

V8Rumble

iTrader: (2)

Interesting. And yes, I was aware of the "soft spring & big swaybar" vs. "stiff spring w/ smaller swaybar" schools of thought, I just find it interesting to see it played out in OEM vehicles like this.

I think I've figured out what I'm going to do, spring-wise - I'm now thinking that I'll buy a set of aftermarket springs in the 550 lb/in rate, & trim probably 1/2 a coil from them - that should allow me to remain fairly close to the stock spring rate (maybe a bit higher), while lowering the front of the car just a bit. I basically like the way the car handles now, & I'm not really interested in trying to "out-think" the GM engineers on something that works pretty well as it is - just want to gain that bit of aero advantage from dropping the front of the car just a bit...

(Not to mention the fact that I really like the "raked" look...)

It would be nice to know the correct length to order though...

Evil86Saleen

Hey man. Most of the CMC racers seem to be ordering a 12inch spring. However you to take into consideration that they are stripped down gutted race cars with every last bit of weight removed. A 12 may be a little bit to low for your car. When I order mine feel free to come by and check it out. Heck test drive the car if you want to.

I should be ordering a set of 12s in the 900lb range for the front. Not sure what I am going to do in the rear yet.

kyle

V8Rumble

iTrader: (2)

Cool, thanks Kyle, I'll do that - I'd like to check out your car anyway! If the CMC drivers are ordering 12" springs, then I guess that these wouldn't work then - crap, I was hoping I could save about 1/3 of the cost I'd seen elsewhere! (I'm sure that part of it also depends on the spring rate you choose as well...)

Thanks again, I'll send you a PM on the other board!

V8Rumble

iTrader: (2)

OK, I performed a different search this morning while trying to help someone else with a question they had, & inadvertently stumbled over the answer to the question that I had! (Don't know why my original searching didn't pull it up...)

It appears that the "free height" for the front coil springs on our cars is 13".
(Including it here in this thread so that others can find it more easily.)

MilehighBird

iTrader: (1)

I'm not sure what replacement springs you are looking for but I replaced my BZW and NNL springs with MOOG #5662 and #5665 springs. The 5662 front springs matched up exactly to my BZW's as far as ride hieght and # of coils. The 5665 rear springs had more coils than the NNL's and raised my rear ride height almost an inch. Hope that helps.

Tidbit

I promise you that is not correct. I have 12 inch free height 800lb springs on my V6 and it is light weight but very low. You put a softer 13 inch free height spring on a heavier nose GTA and it would sit about equal or lower than mine and would rub to all hell. The stock spring has to be in the 14 inch range somewhere and is at a 42% leverage point on the control arm. The stock GTA sits about 27 inch from ground to fender lip- my car with a very stiff 800lb 12 inch spring and a light V6 sits at 24 3/4 inch- put my spring ion a heavier GTA and the fender lip would be more about 24- 24 1/4 inch. my springs are much stiffer than a GTA in the front.


V8rumble, you are not getting to even worry about areo effects in aiding the speed and handling of the car. that happens above 130mph aprox for common performance street cars. as for the big bar setups? That only pertains to a NASCAR Cup car doing 180+ down a straightaway. the soft spring big bar front setup allow the nose to areo push downward dropping the ride height minimum at stagnant tech inspection to allow for another 2-3mph down the straight. This setup is used with massive compression valving up front for chassis control and to helpp keep the coils just off coilbind in bumps. The rear right spring is also pretty massive to help lift the rear and rake the car.


On a 3rd gen? I pefer big spring small bar front, small progressive spring big bar rear- and shock dampers to go with them. BUT It all maters where your roll centers are.

Tidbit

Whoops, I just thought of something. You guys are probably most all still running those factory spring isolators. How thick are they? I do not run any. I use good ol grease and eletrical tape on the spring end that fits into the can pocket.

V8Rumble

iTrader: (2)

Well, one of the primary goals that I have (if not the primary goal) is to get into the '150 Club' on the Bonneville salt - so aero is a significant concern for me. (The related benefits that show up as better street performance & better mpg are just an added bonus.)

Interesting, & quite possibly helpful in my quest. Looks like I might want to look at buying a somewhat-softer pair of front springs for when I hit the salt... (I already have adjustable Koni struts & shocks, which should help me be able to "dial it in" a little bit.)

Wish I knew the height of the spring isolator, but I seem to recall reading that it's about 3/4", which would put it roughly in the 14" range... Hopefully someone will add a more-definitive answer.

Thanks for the reply Tidbit, there's some good info there!

Thanks, that does help! I know it's probably tough to separate front from rear, but how did the ride quality compare when you went from the BZWs to to the 5662s? I'd guess that it would be roughly comparable, but would appreciate a more-definite answer.

It almost sounds like swapping to the 5662s would give me a somewhat softer ride - and if I were to cut 1/2 a coil to get the slight lowering I'm looking for, the corresponding increase in spring rate should put me right back to the ride that I have now! (Give or take a few %) Does that sound reasonably accurate to you guys??

Thanks again guys!

Tidbit

You don't want soft springs up front-Why?- you are NOT restricted to ride height rules on Bonneville Salt Flats. You need to do areo work on the nose and tail of the car. 150 is easy and can be done on stock body panels with the car at stock ride height. I have a daily work truck that turns 142mph on a 340hp motor for christ sakes- its an areodynamic brick. I could gear up the 3.70's to 3.25's would push me to 155 in this brick in drive before I have to go into OD and keep to 75% throttle (I have a $3500 DYt700 in this truck with the valvebody blueprinted-this tranny is as built as you will ever see a standard 700r4- its not stock in any way).


heck, my auto 2.8 V6 Camaro turns 138.9 and has clocked a 123mph speed on a closed road course on Calif Speedway 2.8mile roadcourse.
I've done over 165 in my Vette down the front straight but could not hold the rpms due to duration of time and running out of gear I held it down the straight mostly at about 160 @ 7k rpms (8500 redline). I could gear this car over 190 easy. It happens to run high 10's in the 1/4 on a rad race setup.

Just some food for thought for you before you post next- Areo on your car is rediculous especially if it is retaining any daily street driving. I hate to sound harsh, but people on public forums need to realize there is often alot more experienced people on board shaking their heads at some of the stuff posted on forums- think before you post. I for one am not an educated engineering whiz and will admittingly say what I do not know, but I do have credentials in the business a mile long. Don't make a daily driver a specific built race car- it makes you look rediculous. Think of someone driving a bonneville land speed car to the grocerystore-hmmmm. Just build the car for hardcore street performance with reliabilty and safety as a big concern. you built it fast? you'd better build it also to stop and handle.

V8Rumble

iTrader: (2)

OK, it sounds as though we may be having a "Who's on first"-type conversation here.

I'm not sure where the idea came from that my car is a daily driver - it's been several years since that's been the case. It's actually a "weekend toy"-type vehicle, one that I am entirely willing & able to make significant compromises with. (For instance, a six-point cage is mandatory for vehicles that are attempting to enter the 150 Club.)

No disrespect or offense intended (at all!), but I'm not entirely sure that you're aware of what I've done with the car, & certainly not what my plans are for the car. Significant horsepower is the LAST part of the equation that I'm working on. In fact, I am in complete & total agreement with you on this point, which is why I initiated this thread, I'd like to get everything working as well as is practically possible before I add much more power. (And that includes the driver, I'm hoping to get a bit of auto-x time in this summer as well.)

The comment I made about perhaps getting softer springs was (for lack of a better term) pretty much me "thinking out loud", it was something that I hadn't heard about before, in all honesty it's interesting in an intellectual sense, & seemed like an idea that might be worth researching further... (I also find the idea of a rear diffuser interesting as hell, but I honestly don't see it as being remotely necessary... ) The biggest problem with a street car achieving high speeds on the salt is traction - it's well-known out there that a car can be spinning the tires at over 100 mph (so anything that I can take advantage of, any little bit of info that might be helpful, is something that I'm going to try to tuck away so that I can use it if needed).

Nor am I especially interested in making any kind of significant aero mods to the car. Other than trying to lower the front end some, the only other thing I was definitely planning on doing was to remove the external mirrors.

I'm very much aware that thirdgens are one of the best platforms out there as far as aero & being stable on the salt - and like I said in an earlier post, I'm not interested in trying to "out-think" the engineers who designed our cars. Bit I have been doing a fair bit of research on this, trying to spend money only once & get it right (well, as much as possible) the first time. I've spoken first-hand with people like Dave Sarno & Keith Turk who run the salt every year, I was out there last year to gather all of the info I could on the tech process, chassis setups, how to set up the pit area you use, etc. If it sounds as though I'm some starry-eyed neophyte who's latched upon the "flavor of the moment", well, I guess that I'm just not communicating as well as I'd like to.

None of that is intended in any way to lessen or disparage your experience or what you're saying, in fact, I love the hell out of the fact that you've gotten a 2.8 well into the triple digits! If this post hasn't made you decide to leave this thread, I'd be more than happy to hear any other suggestions you may have - but I felt that it might be worthwhile for me to give a little more info so that your suggestions aren't misdirected.

Thanks again Tidbit.

Evil86Saleen

No problem bud. I will be doing a bunch of experimenting with different spring rates so I will probably have a few sets left over that you could try out.

If you get the time head down to LaJunta this weekend and check out Kents "menace" third gen AI racer. Its got to be the baddest 3rd gen racer in the world.

later

kyle

V8Rumble

iTrader: (2)

Thanks man, I'd LOVE to do exactly that, but I think that my employer has other plans for me, at least on Saturday... I'd enjoy making it down there to see you run as well - were you able to get the license you were gunning for?

Also - did you get the PM I sent?

blyth18md

EDIT: attached file for easier comparisons

Not sure what springs are stock for a GTA but im guessing its one of the few im about to list.

Moog # - 5660 Spring rate - 598 Install height - 10.75 Freeheight - 13.26
Moog # - 5662 Spring rate - 748 Install height - 10.75 Freeheight - 13.01
Moog # - 5664 Spring rate - 707 Install height - 10.75 Freeheight - 13.18

Ive also heard of #5662 of having a spring rate closer to 648 could have been a typo on moog's behalf. Also be mindful that some thirdgens did come with a spring which had a longer free height but the spring rates on those were all under 425#'s

MilehighBird

iTrader: (1)

The ride quality with the Moogs is great. I also rebuilt the whole front suspension and installed new shocks and struts at the same time as the springs but it rides nice and tight now.

Tidbit

V8rumble, (being very respectful and friendly myself ) I should have been just a tad more specific in the last paragragh in my above post. I merely was making a conclusion blanket statement to anyone reading this thread in general and addressed it as 'people'. My thoughts in posting that was to try and keep this thread from going into a post of areodynamics and wanted to nip the unimportance of that only going to 150mph in the butt right away before anyone got further into it. Above that it really wil only matter in squeezing ever extra little mph out of it- but 150 should be fairly easy without areo work done at all


I am also glad to hear you are making a purpose built car and are not intending it to be as a primary vehicle as I have seen many here try and do- and compromise ride quality, safety and mostly reliability in seek of speed thrills.


The next thing I would recommend diving into modification wise on a car built for high speed runs is massive weight reduction for tire delamination safety. Also put in a 16-13:1 progressive rate steering box for high speed control and up the caster but not the camber. Driveshaft critical speed is also a major concern. Need to check the overall driveshaft speed based on trans ratios and rear end gears making sure you have a shaft adequate to sustain those speeds vibration free. Go to larger 1LE hubs for better wheel bearings(you may already have these?). Just basicaly get the nose as close to the round as possible using aprox 6" plastic riveted to the nose of the car. Creates a low pressure zone under the car sucking it down and reducing air drag under the car also. Vent the tops of the fender so wheel well air can escape. as for springs? I wold run about 1000 lb up front and 225 lb out back with about a 30mm front bar and a 19-22 mm rear bar. I would drop the front and rear ride height 1" only (about 26 inch fender lip height in front) for good a-arm geomerty and roll center. Take the side veiw mirrors off windowwipers off, duct tape hood seams and headlight seams. Very good quality 8" wde rims and tires(no need for wider- more roll resistance and drag if wider). Always glad to help and will continue with any more questions.

Tidbit

Blyth, thanks for confirming the facts. My post immediately after the one you quoted on did clear up the possible isolator thickness aiding in ride height. I had forgotten about the large factory units- I do not run them. With the fatory isolators I can easily see where GM did make the pontiac with 13 inch free height springs in those rates you list. Without that isolator you would be lower than mine and would be hitting everthing since the v8 is heaviner and the srpings are softer
.

V8Rumble

iTrader: (2)

Thanks Tidbit - there are a couple things in there that I hadn't considered, but I am working on the weight reduction. Much appreciated!

Evil86Saleen

Hey dude I got yer PM I was just out of town doing a little bit road racing.

BTW I did a little bit of playing around with the suspension before I took the car to LaJunta.

Cut the stock springs (dont know the rates, 91 RS camaro), installed the 36mm hollow front bar, sway bar links and boxed stock PHB with bushings.

Huge improvement over the stock stuff. Turn in is great and the car rotates like a mad man. The car transitions great on the 4-5 turns at LaJunta. 4-5 is a quick right to left series and the car just rotates perfectly.

My lap times would put me in the middle of the CMC pack and 1.3 behind the leaders.

Knowing that take this into consideration. I am a rooky driver with 6 days under my belt, just moved into HPDE3. The car is down 40 hp, overweight by 200lbs, factory alignment settings, 128k on the front suspension and bushings, open diff, 3.08s, drum brakes, stock metric front brakes with performance friction street pads and no name worn out dampners.

Anyway I like the car a little bit loose and it is working well for me being softly sprung. I dont think I will be changing spring rates just yet. The future plans in order are. Get the weight down, decent dampners, 1LE front brakes with the aluminum PBR rear discs, decent alignment, find that 40hp that I am missing and a decent rear gear in the *** end. Changing spring rates is last on the list as right now the car is just flat out working for me.

I had a couple of E36 M3 drivers (one a racer the other a instructor) coment on how well the car gets around the corners and they where surprised that the set up is mostly stock with cut springs. I would love to say that its my excellent driving skills but we know better than that.

However what works for me may not work for others.

BTW I got your other PMs just been super busy. I will get with you over at MHTG real soon.

later

kyle

Jay

iTrader: (2)

The front isolator is at most .250" the rears are quite a bit thicker.

SR-71

GM varied the spring rates based on suspension package, other equipment on the car, the mood of the guy installing the springs in the factory, and the phase of the moon the day the car was built. Same with the sway bars.

My '88 Formula's WS6 springs are HARD compared to my son-in-law's '85 IROC Z's springs (F41 package), and those are known for their hard ride.

By the way, there was no 1983/1984 WS6 package. It was (re)introduced in 1985 models.

Guest

Wow oldish post.

Back in 1987 and 88 when I was buying new suspension pieces from GM they still had separate part numbers for years and load rates. I can confirm the story above about the 84 TA springs, according to what I and the counter person determined, the 84 TA had the stiffest available of anything from 82-87. Thats what I ended up ordering, along with a hollow 36 front and solid 24 rear bar. Then I cancelled the order for the springs because for some reason my 84 already had those springs. Weird. What might have come to the dealer may have been 87 springs but there were different numbers. I'm sure after about 4-5 years GM started consolidating them like they do with everything else.

G-bodies use the same size front springs, but the rears are pigtailed on both ends whereas ours are pigtailed on just one end. Its possible given the design of the upper pocket in back they'd work just fine but they are different. At the very least you'd have to ditch the isolators.

Yes there was a WS6 package. It was revised in 1985 and pretty much stayed the same after that.