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I might have made a mistake on my springs, I have ordered ACDELCO 45H3025 and I am worried they might not be an ideal spring for my car due to information on wholesalegm as well as the 500lb spring rate. Perhaps someone can put my mind at ease and save me a return?
So I am looking for recommendations for the proper set of springs as well as an upgraded rear sway bar+end links.
I am completely rebuilding the rear with a new carrier, and have Koni Yellow shocks that I will be putting in.
I've got an adjustable panhard bar (BMR PHR002H) as well as new lower control arms (Ebay Blackpath).
I'm just looking to have a nice highway ride, with some good handling.
Would anyone have any recommendations for me? I don't really know much about suspension in general, so I'm not sure whether or not to get hollow or solid, the diameters, so on and so fourth. If it's any help, when I spun out and damaged my poor girl, it over-steered like a mother. Swung around 180, could have been driver error... But everything was stock at that point.
Trying to stay under $200 for the swaybar and $100 for the springs. If the springs are likely fine, than a max of $300 for the swaybar, but I'd like to stay near $200.
Thanks! Always looking to learn!
Last edited by Annihilate; Mar 5, 2021 at 04:51 AM.
500 lb rate for rears doesn't sound right. If memory serves, the stockers are variable rate, something around 165 or 175 at ride height. 500 would be about right for stock IROC/TA fronts, seems like people claim numbers like 480 or thereabouts.
It also says their bar size is 1/2in or 12mm. Can you measure the thickness of your current springs? If they're similar, it stands to reason that the rate would also be similar. It seems odd that 500lbs would even be available for street cars when stock is less than half that rate, I'm thinking that the information was miscategorized.
I'll have to take a look when I get home tonight, I'm not even sure if the springs on the car are the stock springs as the shocks and a few other things were changed by the PO.
Hollow weighs less. ALOT less. Size for size a hollow has about 90 - 95% of the stiffness. E.g. a 36 hollow is similar to a 34 solid, at about 1/3 the weight. Seems odd I know; but that's because the outermost "layer" of material is doing most of the work anyway. The rate is approximately proportional to the CUBE of the diameter because of this. I.e. if you DOUBLE the diameter, you MULTIPLY the stiffness by EIGHT.
As far as the brackets, no idea. Maybe you could just bend it back?
You mean the piece I've circled in this pic from the UMI website?
If so, then a junkyard car would be your best source, and I'd guess 100% of the 3rdgens you find will have 100% of those parts still on them. Not real sought-after. Otherwise, a junk dealer, like Hawk's, can probably pull one off of one of its parts cars.
Regarding the hollow sway bar from BMR, yes, weight savings would be considered its bigger benefit. But if there was somewhere on a 3rdgen where I'd want to keep weight, it would be in the rear, given how front-heavy they are. That's probably just me, though. But if I were spending your money on ME, lol, then I'd go for this kit from Spohn, available in black or red. I like the bar, itself, but when you consider the value of the superior Spherical End Links that are included, then the cost is comparable to the BMR and the ST. Camaro Rear Sway Bar | F-Body Rear Sway Bar | Spherical End Links (spohn.net)
What would the added benefit be? Stiffer overall? Would it negatively affect over steer?
I finally got my springs out today and my AC Delco ones seem to be about 2 inches higher. I'll include a picture later tonight, as well as a look at how bent the drive side spring got after my little whoopsie lol.
And yeah, the one you have circled. I might have found someone locally who has one for me.
Last edited by Annihilate; Mar 6, 2021 at 04:41 PM.
On second thought, you're buying a lot of parts right now, and you're trying to keep things simple and inexpensive. And that ST bar posted by 84 z28 should be perfectly fine and leave you with a few bucks to spend on something else.
Rod ends let the suspension work more freely to do its job, but the trade-off is less driver and passenger comfort, due to a harsher ride. So if you don't like to feel the road, which I do, but most people don't, then keep it simple and stick with bushings, especially since it's just for the streets, which, in Michigan, probably vary quite a bit, from good to bad. Besides, sounds like you might have some springs to sort out first. You can drive without a sway bar, but you can't drive without springs!
I read the specs on those springs, and they looked fine for V6 cars and base models, but maybe not so much for the "performance" suspensions of an IROC, Z28, GTA, TA or Formula. Someone in this thread liked them, which is cool, and that gave you hope, and they might be ok. But as you've noticed already, they're much taller than your IROC springs. They're going to be much softer, too. How that will translate in terms of ride height, comfort and control, only YOU will be able to decide.
Rock Auto lists only one rear spring from AC Delco and Moog, which appear to be the exact same product, for all models of Camaros and Firebirds, V6, base and performance, which means it may not be ideal for an IROC. Whereas, for front springs, there are multiple options listed for Firebirds(still just one for Camaros, which is weird, being the same chassis), based upon performance, and that's how it should be, and should've been for the rear springs, too. And that one rear spring is TALL and soft. At least rear springs are simple to test fit. Looks like that's the only way you'll see how they "stand," so-to-speak.
If they don't work out, there's an inexpensive brand of lowering springs on ebay, but you'd have to do the front, too, which may or may not be part of your current plans. In this current thread on TGO, I found them on ebay, also found a youtube video by someone who took a chance on them for his GTA. Both links in post #5. He seemed to think they're ok. They're definitely a bargain, keeping things simple and inexpensive. Touring tech lowering springs?? - Third Generation F-Body Message Boards
i just installed them springs with kyb gas adjust shocks friday evening and very happy with them, they measure and look just like the factory ones i took out.only reason i replaced was because the guy i bought the car from had air shocks with 4th gen rear axle and corvette wheels n tires and road really rough, my ride height hardly change much, prob about 1/4" lower thats it. rides and handles great.
I'm not sure if the PO lowered the car, although it sure looks like it. He certainly didn't replace any other parts if he did, except for a pair of Bilstein shocks.
That's an OE spring, most likely your car's original spring. That dirty little disintegrating paper tag on one of the middle coils is the RPO tag. Gently wipe it off without destroying what's left of it, and you might still be able to read the code. That code should be listed on the car's SPID label, if it's still in the car, wherever it's affixed in a Camaro.
Here are my original WS6 springs, RPO NNL. Yours should be similar, if not exactly the same. Took these out a few months ago and installed weight jacks. First time they've ever been out of the car. They stand about 14-3/8" tall, and the ride height after nearly 34 years was still stock-ish, very little sag, if any at all. And paired with the KYB shocks that were installed in 1993, this shock/spring combo was still solid as a rock after nearly 28 years.
I read the specs on those springs, and they looked fine for V6 cars and base models, but maybe not so much for the "performance" suspensions of an IROC, Z28, GTA, TA or Formula. Someone in this thread liked them, which is cool, and that gave you hope, and they might be ok. But as you've noticed already, they're much taller than your IROC springs. They're going to be much softer, too. How that will translate in terms of ride height, comfort and control, only YOU will be able to decide.
Rock Auto lists only one rear spring from AC Delco and Moog, which appear to be the exact same product, for all models of Camaros and Firebirds, V6, base and performance, which means it may not be ideal for an IROC. Whereas, for front springs, there are multiple options listed for Firebirds(still just one for Camaros, which is weird, being the same chassis), based upon performance, and that's how it should be, and should've been for the rear springs, too. And that one rear spring is TALL and soft. At least rear springs are simple to test fit. Looks like that's the only way you'll see how they "stand," so-to-speak.
Oh boy, another thread on shocks/springs...leaving me confused once again. Mojo had me convinced to go for the ACDelco’s before reading this thread.
Since my car is an 85 IROC, is there no replacement spring available?
I wont be installing the springs for another week or so, but I am probably gonna end up with a set of slightly lower springs more geared toward performance, and ideally, more in line with the original iroc spring.
However, I would still be interested in seeing if there are any proper reproductions out there.
Just realized Annihilate that you’re the original poster of this thread, and we where discussing this on Mojos thread as well. Will pay attention to this thread to see how your rear suspension turns out. Mojo sounds happy with his...
And just bringing in the spring secs that I researched to this thread, hoping it may help.
You say you're looking for a comfortable highway ride. ....why are you replacing springs? ...and why did you break out the wallet and buy the Koni Yellows? First, I've never seen a set of springs wear out to the point where a new set of decent shocks wouldn't fix the ride quality. They might sag a little, and you may not win the local autoX race, but they don't really "go bad". ...and then the Koni's, while awesome, are really designed to be a part of a much more responsive suspension package. Not normally considered a stock replacement. There are other members who can likely elaborate more on the physics/science of it all. I might've missed it, but why are you replacing swaybars? It kinda sounds like you're all over the place with mismatched upgrades. Bigger/stiffer most definitely is not better. It cold be...but not necessarily. The springs and swaybars need to be chosen together, to work together. ...and what happens in the rear doesn't STAY in the rear. It directly affects the front too.
I know you're already working your way down the rabbit hole, but I think I mighta bought some decent replacement shocks and struts, some rubber replacement bushings, and called it a day. I've got a ham sandwich that says you would've been happy with the results
Edit* - just to be clear, I'm not saying NOT to replace springs, and I'm NOT ignoring that you want the car to handle. I just think that with a 30+ year old car with original parts, stock replacements WILL DO WONDERS!!!!!!!!! ....and if comfort is important, as well as budget.... ...well...lol...that's all I'm saying.
Thanks for posting @Abubaca , makes sense to stay original for the purpose of everyday driving. In my case, my rear bottoms out when I have the family in the car (sometimes when I alone even go over speed bumps at slow speeds). However, the car does sit at ride height and when I push the rear down it comes right back, doesn't bounce around what so ever, and doesn't bounce or feel loose around while driving. This is why I believe new springs and shocks are in order for me. I'm fine with getting the Bilstein stock replacement, but unsure of the springs.
Appreciate your input/thoughts on this...
Last edited by 1985_IROC; Mar 17, 2021 at 11:09 AM.
As far as the springs go, when I had bent the housing, I actually bent the driver side spring as well. So I definitely needed a new set. Apparently the OEM replacement was higher than the stock ones that came on the Iroc, but I couldn't find too many variants.
As far as the Koni shocks go, I simply wanted the best. I've seen a lot of people swear by the Koni's, the car had Bilstein on them before, but the driver side shock blew out when I made contact with that friendly curb.
I did decide to hold off on the sway bar for now, and am putting some money into rust prevention and sound deadening for the interior. I'm finally getting my rear end built, taking it to the shop on Friday, and then as soon as she is back on the road, I have a guy to put in the SFC.
That will likely be all the upgrading I can afford to do until later in the Summer. Just wanted my rear as tight as possible.
I think the first thing anyone needs to do with any mod, is to really be honest with yourself about what you want out of it. An IROC, outta the factory was a great handling car, and still isn't too shabby in the corners even 30+ years later. I had my last 89 Iroc suspension pretty stiff and it handled great. So when I got my "new" 88 a few months back, I was pretty sure the old original suspension would be crap. I was shocked at how comfortable it was, yet still handled " pretty good ". Now sure it wasn't great, but I'm here to tell ya, the time in money in the 89 suspension wasn't worth the improvement!!! I basically opened up the catalog and said gimme one of each of those brand name shiny new suspension parts. Not the best plan, I'll admit it. This time I'm really digging in and trying to learn where the money is best spent, and where it'll help me and MY driving style and habits. I'm trying to cure some of the weak points in the suspension design to help handling, while not having it feel like it's riding on rails. A good handling car CAN BE stiff, but simply being stiff doesn't make it handle. I want the best of both comfort and handling, but will sacrifice handling when the time comes.
This is why I believe new springs and shocks are in order for me. I'm fine with getting the Bilstein stock replacement, but unsure of the springs.
...yeah...I hear ya. I wasn't aware that stock replacements were hard to find, so I can't really comment on what's out there, aftermarket or simply stock. I'm just not up on the options for those NOT wanting to go to a performance spring. I've used weight jacks on my last two Irocs. You can adjust ride height (not on the fly) to suit your needs, and it's super easy, and fairly cheap to buy different springs to try different spring rates. That being said it doesn't sound like a solution for your situation.
Im still (sorta) young and just learning as I go along. I figured since I was taking the rear end out I might as well do EVERYTHING, probably not the best idea, but what's done is done. Once I started buying parts it was hard to stop lmao.
Im hoping to spend some time enjoying the car for the remainder of the year, as well as get into my own tunes. I was planning on tackling the front suspension in the Summer. Though, thats a wait and see as well.
So it looks like there are two choices for the rear springs:
One at: 518 load lbs. and the other at 580 load lbs.
Question now is which is correct/best?
What exactly do you want out of the car comfort, performance and looks?
A front Moog 5662 with 706lbs spring rate and a rear 5665 with 107lbs going to be a better ride than with a 5664 with 767lbs springs up front.
Higher spring rates equals harsher ride but better performance, but keep in mind that any factory replacement spring there’s going to quite a bit of wheel gap making your car sit higher
What exactly do you want out of the car comfort, performance and looks?
Hey there 91banditt2!
And yes, we all want comfort, performance, and looks ;-) If we knew the specs for the original NNL springs in the rear, there wouldn't be so many threads or worrying of which replacement to get.
In my case, my rear bottoms out when I have the family in the car (sometimes alone going over speed bumps at slow speeds). However, the car does sit at ride height and when I push the rear down it comes right back, doesn't bounce around what so ever, and doesn't bounce or feel loose around while driving. This is why I believe new springs and shocks are in order for me. I'm fine with getting the Bilstein stock replacement, but unsure of the springs. Don't want to get stiffer than what came with the NNL springs, which is unknown, and don't want to use my bump stops.
And yes, we all want comfort, performance, and looks ;-) If we knew the specs for the original NNL springs in the rear, there wouldn't be so many threads or worrying of which replacement to get.
In my case, my rear bottoms out when I have the family in the car (sometimes alone going over speed bumps at slow speeds). However, the car does sit at ride height and when I push the rear down it comes right back, doesn't bounce around what so ever, and doesn't bounce or feel loose around while driving. This is why I believe new springs and shocks are in order for me. I'm fine with getting the Bilstein stock replacement, but unsure of the springs. Don't want to get stiffer than what came with the NNL springs, which is unknown, and don't want to use my bump stops.
Hopefully getting my rear end back sometime in the next week, just pulled my gas tank out for a fuel pump swap, we shall see how it all goes from here on out!
Hopefully getting my rear end back sometime in the next week, just pulled my gas tank out for a fuel pump swap, we shall see how it all goes from here on out!
I am interested in the fuel pump swap, I had a mechanic do it a couple years ago after taking it out of storage. As I have been driving it last year and this year, noticed my fuel gauge is all over the place. Wondering if I need to pull my tank out and replace the fuel sending unit which is where that resistor is on the float lever bar (technical terms). Maybe a ground issue 🤷🏻♂️
I hadn't considered making a primary thread, I've kind of been all over the place the past few years, this year is really the first year where I am deeply diving in.
Perhaps after it's on the road again officially, I'll compile everything and keep it updated from there.
Your car is pretty sharp, mine was originally red, but it was painted over in Blue, I don't think I could drive a bright red muscle/sports car, seems like putting a big ol' target on your back!
1 month update, the ac delco rear springs are exactly what i wanted, they give you the Iroc ride and handling that i want, just like stock, you guys would not be disappointed.
