84-Z28-Canada

Hello guys, lemme start by saying TGO people have been giving me the best advice to date of any car guys. That said...I need your help. I love the way my car drives, it is an 84 z28. It's low enough to the ground, takes bumps well, and has a really smooth ride. However, the car is now close to 30 years old, and things are wearing out. I've been doing some reading, and the later model Irocs seem to have a good reputation for handling and performance suspension, while still being factory. So, my question is: Is an 88 or 89 Iroc suspension set up 1) transferable to my car, and 2) an upgrade? Let me hear your thoughts, looking forward to it

84Z

Reid Fleming

iTrader: (2)

Back in the day, sure it was an upgrade. Better springs. Probably better shocks. Lower profile tires on larger wheels. Possibly a bit lower stance as well. Steering ratio was very quick in the IROC cars.

Today? I'd say no. 25 year old suspension is 25 year old suspension, whether that's IROC or Z28 or Berlinetta. Most aftermarket suspension pieces are listed as 1982-92 and the differences between stock 25 year old parts vs brand new aftermarket is quite stunning. Even the advances in tire technology alone are good. The old Gatorbacks were as good as it got back then. Today, nobody would think of running those.

fireturd350

iTrader: (8)

Wonderbar would be good to swap on if you don't have one. Shocks/springs are probably pretty old by now. Aftermarket parts for these cars are easy to find right now.

toxik IROC

iTrader: (12)

x2 for the wonder bar. if you have to buy (or want to buy ) upgrade to aftermarket their alot of good brands out there that would help you give you your camaro some performance again. and it could be done with out making it way to harsh of a ride. I would deffently start reading reading and more reading. you also can check out umi,sphon(sp?) for some good info.

DJP87Z28

Upgades for your suspension would be to start off with Struts, Shocks, sway bar end links, SFC's. I would also replace the wore outsteering parts.

sofakingdom

iTrader: (1)

The "suspension" - control arms, spindles, torque arm, and so on - is the same. Only things that are different are the springs, struts & shocks, and sway bars. Of those, the only ones that aren't replacement wear parts, is the sway bars; the others are routine maintenance, and are like, say spark plugs or oil: you wouldn't consider changing your spark plugs or your motor oil to, say, used ones "out of a Corvette", as "upgrading" your "engine" to "Corvette specs", would you? same deal here.

The only "suspension" parts to get off of an IROC are the sway bars and the "wonder bar". Those parts are the only ones that are different from what you've got that aren't wore out. The rest would be just some other old wore-out garbage.

Good springs to get are Moog 5662 or 5664 for the front, and CC635 or 5665 for the rear. FAR better than any that ever came in any stock vehicle. And... best of all.... NOT WORN OUT!!!

One other IROC part that might be better than what you have, is a steering part; the gearbox. Yours might or might not be the same ratio as what came in IROCs, which was 12.something IIRC. The low-perf version was about 14.something.

84-Z28-Canada

this is fantastic stuff guys, thanks very much for all the information. the wonder bar is a good call, and perhaps the sway bars as well. When people advertise the 34/23 mm sway bar set-up, this must be out of the IROC, correct? because I know mine do not share those diameters. Great suggestion on the moog springs as well, new springs that won't rock the boat over bumps and allow for a comfortable ride. As opposed to say, Eibach pro-kit, which drops the car an inch or so and is much stiffer.

toxik IROC

iTrader: (12)

With the pro-kit some times people think it raises up the car, and they are confused becuase they are lowering springs.They get confused because it actauly lowers the car but it sits higher, b.c old worn out components.

Guest

5663?
The 5664s are the stiffest fronts, but AFAIK, the next spring down is the 5662. And it seems to me that most of the threads I've read are 5662s that the person ended up very happy with.
As for bars, the 36 mm hollow front is lighter than, but not as stiff as, the 34mm solid front bar. In back, the largest was a 25, not sure if hollow or solid.
Your '84 bars should both be solid. The aftermarket has a variety of sizes in both hollow and solid versions.
Going with moderate springs and serious bars will give a better ride, but for twisty track racing with lots of cornering, get stiff springs with modest bars.
For rear springs, the Moog CC635s are progressive rate and seem popular, but there's also the Moog 5665. Constant rate.
But before any of this, start with polygraphite bushings for the front arms, new balljoints, new idler arm, new tie rod sleeves, new tie rod ends, new shocks and struts, and subframe connectors.

JamesC

iTrader: (5)

Hey, ronjonn, do you have a source for that info? No hollow OE rear bars that I've ever heard of.

JamesC

Guest

The 25 mm rear bar was offered, at least once, but I'm not clear on year or WS6 / F41 / whatever.
As for hollow rears, if you say they never happened, then I can't and won't dispute you. IDK, really.
Since hollow fronts happened, then hollow rears must have been technologically possible.
Sorry if I muddied the waters, that wasn't my intent.

JamesC

iTrader: (5)

The following is from Ed Miller (the thread is located in the FAQ section) and might be useful here:

I got all this info from my parts and illustration manual. Those things really help a lot, and if you do a lot of part searching, I would get one...it'll save you a lot of time. Also, look into the CD rom version listed on the home page.

FYI, RPO codes are as follows from the decoder:

F41 : SUSPENSION SYSTEM, FRT, RR, FIRM RIDE, HANDLING
FE1 : SUSPENSION SYSTEM, S0FT RIDE
FE2 : SUSPENSION SYSTEM, RIDE HANDLING
FE3 : SUSPENSION SYSTEM, SPORT
Unable to locate code ZK3 in our database!
Z28 : MERCHANDISED PKG, SPECIAL PERFORMANCE

ZK3 is the export model so if you have one, you know who you are. Part numbers follow the descriptions.


91 F41 FRONT (34 MM) 14094339
91 F41 REAR (21 MM) 10021221
(REAR POSSIBLY FE2 ALSO)

91 FE2 FRONT (36 MM) 14094344
91 FE2 REAR (24 MM) 10035033


90 (NO CODE GIVEN) FRONT (36 MM) 14094344
90 (NO CODE GIVEN) FRONT (34 MM) 14094339
90-91 FE1 FRONT (30 MM) 14047916
90 (NO CODE GIVEN) REAR (24 MM) 10035033

89 FE2 FRONT (36 MM) 14094344
89-91 FE1 REAR (18 MM) 10021220

87-89 FE2,F41 FRONT (34 MM) 14094339
88-90 FE2,F41 REAR (21 MM) 10021221

87-89 EXCEPT FE2,F41 FRONT (30 MM) 14047916
87-88 EXCEPT FE2,F41 REAR (18 MM) 10021220

86 (NO CODE GIVEN) FRONT (27 MM) 14019268
86-87 EXCEPT ZK3/Z28 FRONT (30 MM) 14047916
86 ZK3/Z28 FRONT (34 MM) 14094339
86 EXCEPT ZK3/Z28 REAR (18 MM) 10021220

85 FE2 FRONT (34 MM) 14073013
85-87 FE2 REAR (24 MM) 10035033
85-86 ZK3 REAR (21 MM) 10021221
85-86 Z28 (EXCEPT FE2) REAR (21 MM) 10021221

84-85 ZK3/Z28 FRONT (32 MM) 14047917
84-85 EXCEPT F41, ZK3/Z28 FRONT (27 MM) 14019268

82-83 (EXCEPT Z28,F41) FRONT (27 MM) 14019268
82-83 Z28 FRONT (32 MM) 14047917
82-85 F41 FRONT (30 MM) 14047916
82-84 Z28 REAR (21 MM) 10021221
82-85 F41 REAR (18 MM) 10021220

Also note the following from Hotchkis:

Are solid sway bars stronger than hollow sway bars?

Answer: No. Sway bars work off of torsional force (twisting motion). Therefore, the material in the center of a solid bar plays little role in the resistance of torsional force. With this in mind, we have eliminated some of the center material and also moved some to the outside of the tube, where it is most effective. In turn, this produces a sway bar that is lighter in weight and just as stiff, if not stiffer than solid. For example, a 1'3/8" hollow bar is equivalent to a 1'1/4" solid. But the 1'3/8" hollow bar is 6% stiffer and 43% lighter than the 1'1/4" solid.

JamesC

Guest

Thanks, I guess. Seeing this, I just had to go out and measure mine, so now I'm all sweaty. Dammit. But my '84 has the 32 / 24 combo, and is virgin.

Reid Fleming

iTrader: (2)

Agreed. I would do struts, shocks, springs first. That's where the biggest improvement per dollar would be.

If you're on a budget for struts/shocks, do the KYB. If you plan on owning the car for a long time and want the best performance while still retaining comfort, get some Bilsteins or Koni. I love, love, love my Koni struts/shocks. The difference with them alone is amazing.

I'd wait on the sway bar endlinks until you change the sway bars.

Subframe connectors are a must on any F-body.

Very good post. If you can get a 36 mm front sway bar off an IROC/WS6 car, go for it. Otherwise an aftermarket 36 mm sway bar would do the trick.

For the Wonderbar, I'd suggest getting the bar from TDS. It's slightly bigger than the stock IROC bar and it fits like a glove! Also has an extra bolt hole for added connection. A 5 minute install job. A cheap suspension purchase that should be on every F-body.

For a V8, you can't go wrong with the Moog 5662 or 5664 up front. The stock rate on an 84 front spring is probably around 400 lbs/inch. The 5662 is 700 lbs/inch while the 5664 is 750 lbs/inch. Generally people can't notice a difference in feel unless there is about at least a 10% change in spring rate. I'd recommend the 5662.

For the back, the difference between the CC635 and 5665 springs is that the CC635 is variable rate while the 5665 is slightly more performance oriented with it's linear rate. The springs will fall out when you change the rear shocks, so there is essentially no labor charge for installing them. The variable rate rear springs tend to sit a tiny bit higher than the linear springs. My car's rear height is 28.5" in height with the 5665 and new shocks.

Rear sway bars are a bit trickier to size. But with higher performance springs, you can get away with a smaller rear sway bar. I'd change this last after doing all the other stuff.

The steering ratio in F-bodies is actually a bit quicker than the Corvettes of the same years. C4 Corvettes in the 1980's had 15.5:1 (base) or 13:1 (Z51) ratios. In the 1990's, they got rid of the 13:1 ratio I guess because people complained the steering was too quick....... Fast forward to C6 Corvettes and the ratio is still in the 15:1 area. But that's because those cars will do 190 mph. And a 13:1 ratio would be way too quick for driving at that speed.

IROC/WS6 cars came with a 12.7 ratio. I love the quick ratio myself. Would I change a 1984 car to this? I'm not sure. If you're used to it, you might want to keep it.

Guest

My '84 has the 12.7:1, stock. Yours might also, but if it's Canadian or export, then I'd be willing to believe it if it was 14:1 Not a dramatic difference between the 2.

JamesC

iTrader: (5)

Here's some general info (I'd like to give credit, but I don't recall where I found the info):

• “WS” – 1982-1992 Camaro – 12.7:1 ratio (just like your Z/28, this may be the box that you Z originally had.

• “XH” – 1985-1992 Camaro – 12.7:1 ratio (this box was also installed on Z/28’s and other high performance Camaros; it has slightly more steering effort required than the WS box.) NOTE – I believe this box was used on cars originally equipped with 16” wheels

• “WN” – 1982-1985 Camaro – 14.1 ratio

• “WP” – 1982-1985 Camaro – 13:1-15:1 variable ratio (used in Berlinettas, least steering effort required of all third gen. Camaro steering boxes)

• “JL” – 1986-1992 Camaro – 14.1 ratio (base Camaro steering box)

JamesC

Krik

iTrader: (4)

Don't say nobody

Guest

Agreed. Plus, Goodyear still offers them in the 245/45R17 size, because until a couple of years ago, new Mustang GTs still came with them.
However, by '87 or so, Gatorbacks were no longer the best. Pirelli had the new P-Zero, Bridgestone had the new Potenza RE71, and BFG had the new Comp T/A.

Krik

iTrader: (4)

Just for the sake of having the "correct" tire on my car I would consider buying a set if they were both available and affordable.

84-Z28-Canada

Everybody on here has been very, very helpful. It's looking like the only real advantage to original IROC suspension over my own is the wonder bar, and now the aftermarket makes better ones. If I could get a cheap IROC wonder bar, and perhaps the 36mm front sway bar (if it is the hollow one) for a great deal, its sounding like that is my best budget upgrade (with poly bushings and stab links). Following that,SFCs, Struts and springs (where good moog springs will provide a good ride and more performance than my old springs without stiffening the ride to much) This all sounds like a great winter project guys...well, that and body work. I will asking for lots of your help in the future!

Guest

SFCs FIRST!!! Some fail, but that's like trying to build the house before building it's foundation.
I seriously doubt you'll ever find a solid 36 mm front bar for these cars.

vorgath

Cheaper to find used bigger sway bars at a junkyard or see if anyone's junking their 3rd Gen. That's how I got hold of a 36/24 combo.

I wouldn't mind getting hold of the Iroc/Z28 steering box though.

tim3058

Hi 84-Z28-Canada,

For what it's worth, I've got an almost stock '86 Z28, and swapped out the stock (broken) springs for a set of 4 of Summit's $180/kit 1" drop progressive rate springs. I'm real happy with the result, I removed the front rubber dampers above the coils (so maybe 1.25" drop in front) and the car's got a nice stance, and the ride is great. Firm, corners real nice (imho, no expert in road racing), but most importantly, soaks up all the minor bumps smoothly. Nice mix of both worlds for $180.

Johngypsy

I know this is an old post, but we have readers out there who are still at the search point of there new Camaro or Trans am,

Here is thr deal, correct me fellas if I am wrong,

Can't find a Iroc z at junk yards any longer, find yourself a 1991-1992 z28 car, the steering ratio is at 2.5 turning circle, the parts fro Ln there is more amazing then most Iroc z's out there,

They carry the 36.2 front sway bars,
The rear 24mm rear,
With the best struts for a buget? Grab the GR2, bang for the buck, I have them on my 90 Iroc z and feels more amazing then ever, just please stay away from the monroe and another chep brand, as I've picked up a set for my 96 vette and my Iroc z and I've bottomed out almost instantly! Yes,,,,, took them back for a refund,

But if your not doing cross county driving or want the street Corning and now and then weekend car, or just want the best set up that u can get? Here is what to get....

1) front and rear koni' est 600 from thmotorsports.com
When on sale, speak to sales rep and say u are with 3rd gens for a 20% off special. Got mine for 550 shipped adjustable ones,

2) like the boys here said, a 1 inch lowering springs front and back, don't get 1 & 2 so this way your car will be nice and leveled out, cost about 299 to 399, worth the money.
Thmotorsports will have u covered also,

3) they also have the front sway bars 36.5 front full medal but light about 1 pound difference and only 100 dollars, do not get thr adjustable ones, wast of money,

4) rear say bar, 24.2mm for 80-100 no adjustable ones,

5) rear pan hard bar, 100 adjustable ones

6) front strute tower brace about 140-250 depends what style u want? It will hold the same resistances to the car, THMOTORSPORTS or even better from j&b parts

7) rear sub fram connectors are like the guys said here is a must, all of our 3rd gens are know to tweek, rattle, and in most cases after a bump or a dreeded pot hole our cars would have a sesure attack, this will 100% stop this, so no more rumbles, get thr welded in ones for a better security fit and feel, sphoons for me, but others out there have some other realys for there choice, sphoons offers a few more support bars thought to make a semi cage type box so u will not feel anything when over a bump, and you will again notice the difference, I promice you,

8) now with the lowered 1inch springs you have goijg, it will be nice to make your car stick to the ground better and no wheel hoping,
Sphoons rear relocation bracket, this will make, feel, and respond so well when doing all of this, a simple weld in applaction for only 59.99 and will even out thr rear end for a proper stance, a must to invest into,

9) got the extra time and cash?
Sphoons offeres a rear torque arm that's adjustable, with the transmission bracket plate, u will again have the time of your life with this upgrade! You will no more transmission rumbles, no weel hoping when u take a corner and will stay into a stright line, it's adjustable to the car and your mechanic will simply adjust the settings fog you, make sure u also buy the extra meter to dial in the proper settings,
550 complete and 15 dollars for dialed tool measurement,

10) rear adjustable arms, they have the box ones, steel, they also have the hollow ones to, bushings, and even the swivel ones, stay away from the dual swivel ones, get the ones with the polly bushing and the other end with the swivel link,

When u take that turn you will make a stiff (ER) more sharper Conner like no other, the dual swivel ones will work great to, but be prepared to hear noises from the rear end, as there is no Greece to be put into, so u will have medal against medal, so the best is the polly end and the swivel ones, only 150-240, any company will do,

11) get a set of strute front monts, to me they are expensive, 200 and up for some performance ones, but a new set of oem ones will do just fine for under 60 dollars for thr pair, or opp for the moog, which are one of the best for our cars, and are a out 300 for the set, this will again make your car handle like it's brand new,


There are a few more uogrades that's made for the 3rd gen, like A-arms, plus much more, but this will only be for looks, racing tracks, ect.... As a good friend of mine told me, be done the a-arms, the shocks with the springs inside of them, full k member and went all out on his show car, I've asked him as I was serious about doing the same to mine, he told me, john, if I can do it all over again? I would of never done this set up, he told me that the car turns like a train, but the ride is so awful to him, he said he would of done the regular set up I e listed, and he spent almost in double in parts and labor install, grant it that he has done it all to the car, but he feels like it's not a sunday or even better yet a daily driver car,


So what all this Ive stated to the parts listed above, from 1-11 in parts, your 3rd gen will drive, feel, perform, like nothing ever felt, literally like a corvette feel, u can take a turn at 40 mph and feel likes its only 10 mph,

As these guys here stated the same and from the 3rd gen reviews of what's the best out there to get, I've bought all of this for my car, have not yet installed it until I paint it next month, I bought a few parts a month and costed me? Well, I don't want to think about it, but was. It cheap! But I know the end result will also add value if and when I do sale my car, once they drive it I know I will get my full asking price because if these uogrades. And best part about it is, NOT one part can be seen and will hold the look of the Iroc z car, and will look 100% stock until it's up on a ramp,

So sorry for the long list as I know there are tons of guys wanting to know the best bang for the buck! And when u drive your car? Just take care of it, it Will always hold the value, and the value of our hearts to be.....

Hope this helps our new readers out here who just bought there first or project car to be done the proper way........

John
Iroc z parts and supplies
Houston tx...