I just got an 88 WS6 Fomula nad I already own an 87 IROC.
The IROC suspension is much stiffer, I feel every little bump, and it corners much flatter thatn the Formy.
I am just wondering if I possibly have aftermarket springs in the IROC, because there is no comparison to the WS6 set up as far as these two cars go.
The WS6 is forgiving going over pot holes etc, where the IROC going over the same bumps is bone jarring.
Are the two suspensions supposed to be equivalent, or are there different levels of WS6?

------------------
Proud owner of the slowest L98 in the North East
1987 IROC 5.7 - 16.43 @ 82
1986 S10 4x4 w/93 Vortec 4.3 needs fuel line and driveshaft
1988 Formula WS6

 

Maybe the Formula's springs are worn out. On my 88k mile WS6 T/A, the ride is the harshest that I've ever experienced in a car, but the cornering is phenomenal... hard enough to rip the side of your face off in a turn, and able to do 90 degree turns at 40mph. VERY tight, actually too tight from a driveability standpoint.

Maybe your IROC has the BZX spring package. WS6 and the regular IROC suspension are supposed to be roughly equal. The IROC suspension has the Wonderbar up front, while the WS6 setup uses a larger front swaybar.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

supposed 'peanut cammed' car (yeah, right)

Built on Wednesday

 

I think the IROC has a better suspension than the WS6 cars. I put the wonder bar on my 86 WS6 T/A and it "feels" stiffer when I corner. I don't know if it is psychological or not.
On the other hand, I also changed to Poly bushing in the front as well, so I guess it is really stiffer. Damn, I confused myself there for a second.

------------------
Zepher
'86 Pontiac Trans Am WS6, LG4 305, 5 Speed, CF DF Clutch,
Edelbrock 1406 Carb, Edelbrock Performer RPM 7101 Intake Manifold.
Edelbrock Open Element Air Cleaner: Flowmaster Exhaust, 160* Thermostat,
Grant GT Steering Wheel, MSD HEI Coil, Taylor 8mm Wires, Recaro Seats,
Alpine CD+Changer,Rockford & Soundstream Amps, Premier TS-1040C Subs, Polk Audio highs/mids.
Best ET: 14.94@91.67
WS6 Trans Am

 

Didnt the IROCs come with stiffer springs? I thought they were the only model to get the BZW fronts. And the WS6 had the softer CDBs on the front like the 91-92Zs?

------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

[This message has been edited by MikeH (edited December 20, 2000).]

 

My '87 formula is a WS6 car.Came stock with BZW up front and NNL springs in the rear.

 

So they were offered on both models. BTW.. My 90 IROC has BZW front and NNN rear springs. With 36mm front and 24mm rear swaybars, both are factory stock.

Jay.. what springs do you have on the pontiac? They should have a 3 letter code.

------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

[This message has been edited by MikeH (edited December 22, 2000).]

 

Not sure on the RPO code for the Formy. Haven't checked it out yet. I just got it a week ago. It's in storage now until the spring when I can work on it. I'll have to get over there and check this weekend.

the IROC doesn't have a BZX code but has this listed -
6ZX : SPRING, COMPUTER SELECTED, FRONT, LEFT HAND
7ZX : SPRING, COMPUTER SELECTED, FRONT, RIGHT HAND
FE2 : SUSPENSION SYSTEM, RIDE HANDLING

 

Sounds like your car does have the bzx springs. 6zx/7zx is the code for Bzx springs. They are even stiffer than the bzws. No wonder the formula springs were softer.

What springs do you have on the rear of the Iroc?

------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

RPO codes for the IROC

9NL : SPRING, COMPUTER SELECTED, REAR, RIGHT HAND

doesn't seem to be a left rear spring listed.. i may have missed that one when copying them down. lol either that or it doesn't have a left rear spring

I can't find the RPO code sheet for the Formula though. No clue where to look.

 

Hey Jay, The turn signal lenses on the fenders in your pics are the clear? if so where do you get them at?

 

nope they are normal amber colored lights

 

Jay

8NL is the RPO for Computer Selected Rear Lefthand Spring

 

My 89 formula (WS6) has BZW on the rpo AND my 87 IROC has BZW on the rpo

------------------
87 IROC, 350/5 speed. gmpp 350, vortec heads w/some work, XE268, 1.5rr's, 650dp, rpm intake, MSD ing., ect.
89 formula, L98.

 

Boy...Talk about bringing back a dead post!

My 89 has BZX on both front springs, but a VIN decoder brings BZX up as a blue rear bumper, or some such nonsense.

Where did the TGO VIN decoder go anyways? And, what is the difference between BZX, 6ZX, AND 7ZX?

 

I took another look at the springs...

Both have BZX on them, but the pat #s are different, I think. On one spring, it's difficult to make out the last number.

Anyways, the part #, that I could 100% correctly mae out, is 1402938.

Any ideas on these spring?

 

im taking it as the 6zx an 7zx springs are more in the line of the 1le springs which is what was in my car till i took them out and put in the pro-kit now i know why my cars handling went from a 10 to a 2!

 

So, are you saying the pro-kit (Eibachs?) made your handling MUCH worse?

All the more reason to cut your 6zx, 7zx springs, for lowering, rather than buy aftermarket springs.

 

I've had two Formulas ('88 and '91) and two IROCs ('85 and '90)

By far, by a country mile the WS6 outperformed the IROC in every case I can think of. A WS6 in decent shape is like riding on rails.

I have spent alot of money on my current IROC ('90) to get it to behave like my '91 Formula sofar still come up short.

The only solution I can think of is to have one of each (Formula and IROC) ... have to tell the wife the news...

 

Just put WS6 stuff on your IROC then!

We took the springs, swaybars, and wonderbar off the IROC parts car, and put it on my wife's 90 RS, and on put a set of GTA crosslace wheels, in place of the 15's thhe RS came with. It was like driving a new car!

I guess I won't be changing out my GTA springs for aftermarket lowering ones. Everything here says the WS6 springs are best.

 

I've got adj struts/shocks and Eiback sportlines on the 90 IROC

It looks great but now I think I should have gotten a 1 inch drop instead of 1.6. Too little travel.

 

You can always get upper strut mounts that not only raise the mounting point, but provide more alignment adjustment. For the rear, you can drop the lower shock mounts down to compensate.

 

Guys, your forgetting about tires. When I went from v rated tires to a nearly identical z rated job, the ride became much harsher and handling improved all around. Some IROCs got z rated tires, some didn't. All the ws6 cars got them (i think) Assuming the owners replaced them with the same rating... well you get the picture.

 

I claim dumminess

Upper strut mount? Do you mean modifying the one I have?

how do I drop the lower shock mounts down?

 

For the fronts...

These from Spohn...

or these.

For the rear shocks, I don't know of any off hand, pre-made, but no reason you couldn't extend the axle mount down, by welding some new steel on them. Simple bracket/mount work.

 

I’m not positive about how IROC and Z28 suspension rpo codes really worked, but the WS6 is meant to be the equivalent of the 1LE camaro suspension and whatever it took RPO wise to get the same springs/sway bars in an IROC/Z28.

That being said:
1- which actual springs you got depended on how your car was optioned, more options and heavier corner weights as it went down the assembly line and you got stiffer springs, which was intended to keep things pretty consistent no matter how it was equipped.
2- Chevy has always been considered sort of the economy division and Pontiac performance, but also slightly ritzier (ever notice how the same year ‘bird/formula/TA seats are slightly nicer then similar camaro ones, until ’98 when they finally just got the same ones?), and being the performance division, the firebirds always got one step stiffer rear springs and if possible sway bars, giving it a more aggressive, more neutral/less understeer, feel. I’ve also heard that they got a slightly more aggressive alignment from the factory, but I have no real evidence of that (and how many little/no mile cars still exist that we can check it on?).

 

WS6 cars got the same options as the IROC/Z28. It seems to be pretty random as to what cars got what springs/ sway bars from the checking that have done over the years.

1LE spring codes are different. The WS6 tag was in use before the 1LE cars, it's just a gimmick, like the ERS label on the audio systems.

That old Formula I owned had BZW front springs and NNL rears, 36MM hollow front bar.. and I believe 24MM rear.. it's the same suspension that my current 88 IROC has and was factory optioned with.

As someone posted, the tires can make a big difference in how the car rides. I noticed that when I bought new ones for the current car.

My old sig.. too funny. That poor car had a best of 14.21 @ 93 by the time I finally sold it. still runs strong as ever with about 230K on the engine.

 

To answer your question, the numbers are just indicators of where they go on the car 6 right side front, 7 left front or something like that, but they are both BZX springs, they are interchangeable side to side it think it's just a matter of an indicator for assembly that it got matching front springs.
I have part numbers for up to BZZ which would have been the stiffest front spring offered, but have yet to hear of any car actually getting those springs.
As I recall it was BZZ, BZY, BZX, BZW with BZW being the softest. I think beyond that they go to a different line.

 

Thanks. I guess mine were just the "standard" BZX spring, but that doesn't explain the different part #s. If the rain quits, I'll go ou and get the #s, and research. I thought I did, but can't find anything.

 

Or these mounts. I have them on my car and I love them. Had to trim the hood to fit, but this may be because of the hood itself. They are strong, have a lifetime warrant, and allow for independ adjustment of camber and caster. However, they don't allow quite as much travel over stock as do the Spohn ones (the good ones, not the standards. The standards are stock repalcements as far as I know).
You could always order some custom springs from Eibach or the like that are stock rate and heigth. Be like a new car (well, springs at least).

 

Jay

What do you mean by softest???? I am just curious becasue the BZZ, BZY, BZX and BZW springs all have the same spring rate of 96N/mm, or 548lbs/in. They were the only front springs avaiable for the 1982 Z28s. Not sure about the Pontiacs, but I would expect they would follow suit. As it appears that GM's focus with all the different springs was to acheive that same ride height, regardless of options, I have to assume that the difference among these four springs is one or more of their dimensions, to get the same spring rate.

The other two front spring rates for the 1982 Camaros was 50N/mm for the base suspension and 70N/mm for the F41 Sport Suspension.

I would also assume that to get a "softer" ride you would need a spring with a lower spring rate.

I have BZW springs on my 82 Z28.

Dave

 

The “BZ” part is saying “hey, I’m a performance option spring.” The 3rd letter after that was which in that series was chosen to match the options/weight of the car. Earlier cars had a lot more BZW’s because they tended to be lighter, where later cars saw more BZZ BZY… because they were heavier.

The F41 RS camaro front springs were softer (about 2/3 the spring rate) and had “BX_” spring codes…

Most, if not all of the rear springs were “NN_,” somewhere I had a complete list of them.

Again, similarly optioned the ‘birds got slightly stiffer rear suspensions then the camaros.

 

Perhaps I am interpreting the parts information I have incorrectly.
According to the catalog I have it lists the springs according to
load rate highest to lowest. I guess I was wrong in thinking this was
the same as spring rate?

 

the BZX springs should be 14029398. I think your part number is missing a digit.

 

The 2 1LE RPO tags I have saved that I could find, the 350 car got CDB front springs and the 305 got BXY. They both list NNN for rears.
These are both listed under the FE2 suspension.

I started copying all the spring codes I have to a table, but it's a lot of typing