Suspension and Chassis Questions about your suspension? Need chassis advice?

Suspension upgrade

Old May 11, 2026 | 09:27 PM
  #1  
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Suspension upgrade

Hi all,

Has anyone installed suspension upgrade kits on there IROC.....in my case 87. It does have the stock upgraded handling package but im wondering if there are better options and which brands. Thank you either way!!
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Old May 11, 2026 | 09:46 PM
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Re: Suspension upgrade

In what way would you like improved? That will help people give ideas aimed at outcomes you want.
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Old May 11, 2026 | 10:11 PM
  #3  
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Re: Suspension upgrade

Originally Posted by QwkTrip
In what way would you like improved? That will help people give ideas aimed at outcomes you want.
Better handling.....my springs and bushings are worn so I was looking at Detriot Speed and QA1....needless to say costly. Was wondering which option is better and is it worth the money? Thank you
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Old May 12, 2026 | 06:56 AM
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Re: Suspension upgrade

Is this a street car, dedicated track car, or somewhere in between? I'll ramble a little bit and tell you about some of the options/ what I've done to the suspension on my (predominantly) street-driven car, that I definitely need to take to a track soon

There are tons of suspension/ handling parts available for thirdgens, all depends on what you want the car to do/ your budget. QA1 and Detroit Speed are probably the two best parts designers as far as innovation within the thirdgen space, though as you mentioned, very pricey. I've had good luck with both UMI and Founder's parts (wonder bar, upper strut mounts, rear LCA relocation brackets/ LCAs, panhard), though this can all add up as well; I've done my suspension upgrades piece by piece over the years to keep immediate cost down. If you're not looking to spend a ton of money, you'd probably do well with something simple like new upper strut mounts to start off (assuming your IROC has the factory wonder bar; if you DO NOT have a wonderbar, that should be your first upgrade). The stock strut mounts have rubber bushings, and they can deflect quite a bit. Aftermarket USMs have bearings in the top to get rid of that deflection, and help stiffen the front end feel up a fair bit.

If you already have the big sway bars from factory (35mm iirc for IROCs up front, 23 or 24mm rear), then you could just get some new poly bushings and end links and be in pretty good shape. The aftermarket sway bars are nice, but not all that different in size. Sure, chromemoly is an upgrade, but the stock sway bars do just fine if you aren't looking to set track records; new bushings help a ton, and are fairly cheap. Shocks also make a big difference in handling, and I've been quite happy with my Konis. They aren't exactly cheap, but as far as shocks/ struts, they're pretty much the best you can get without shelling out for coilovers. Koni has a sale every July, so get 'em in July if you have any interest in them. Think I paid $750 for my full set back in July 2023, vs the usual of close to a grand. KYB AGX struts are also pretty well regarded, but I've heard the rear shocks can be a bit harsh, even on the "softest" setting.

For springs, you can go as simple as Eibach lowering springs, or as fancy as somethin like Ground Control weight jacks (again, assuming no coilovers). I finally bit the bullet on GC weight jacks last year, and I've been super happy with how they changed the car. They folks at Ground Control will help you pick spring rates for the front and rear, depending on your motor/ what you want the car to do/ what shocks you're running and all, springs are included with the price of the weight jacks. The weight jacks also give you relatively easy height adjustment. If you do go for weight jacks, I'd recommend just getting the standard ones for the rear. I opted for the "upgraded" rear weight jacks, and while they are quite nice, I didn't realize that I'd have to cut out an access panel in the bottom of the driver's side spring perch. Not a big deal, and may not matter if you have a 9 bolt, but something to keep in mind.

If you're looking to stiffen the chassis, subframe connectors are gonna be what you want. They tie your front and rear subframes together so your car isn't held together by the floor pan (yay unibodies!), and I'm hoping to be able to get them soon. You'll want them welded in, which is what's been stopping me for the moment.... you could pair those with Alston's inner SFCs if you wanna get crazy, but most folks are more than happy with just the outer ones. From what I've heard from my thirdgen friends, the UMI SFCs are the best option for the outers (regular SFCs).

For a-arms and k-members, if you want to drive your car on the street, stock is honestly going to be your best option (unless you want to shell out big money for QA1/ Detroit Speed). There's a good bit of talk on this site about a-arms and k-members from other companies tending to crack with street driving, guess they weren't really designed to handle all the bumps and potholes. The stock stuff is actually quite beefy, and these are usually only replaced for weight savings/ extra engine bay space/ adjustability. If you want to replace your a-arm bushings, Global West's Del-a-Lums are going to be the best you can get. They replace the stock rubber bushings with a solid aluminum sleeve and a delrin bushing, which completely eliminates deflection on the a-arms. I put these in earlier this year, and they've been absolutely wonderful. Seen some anecdotes about them lasting well over 100k miles/ 20 years, Global West has been in the delrin bushing business for decades, and they have great customer service. They ARE a massive pain to install though, since they're so precisely machined, and you're gonna want to use a hydraulic press for them (or pay a shop to do it, which is what most folks do). For ball joints, avoid AC Delco, their ball joints are junk unfortunately. I had to pull my new ACD ball joints back out immediately because one wouldn't take grease (and ended up splitting in half), and the other wouldn't hold grease. I put in a pair of Mevotech Supremes, working great. Don't get any fancy low-friction ball joints if you plan to drive on the street, totally unnecessary on anything but a dedicated race car.

In summary, you can definitely get pretty significant results if you want to put in the time and money, but if you're just looking for sportier handling on the street, new bushings will go a long ways. Good cheap upgrades are gonna be the Founder's LCAs ($120 or so), UMI's LCA relocation brackets (about $80), and new bushings on your sway bars (about $70 including end links if you go poly). Shocks/ struts will help further with body roll and ride, along with springs. Upper strut mounts will help further with preventing deflection on the front struts, and give you more adjustability. You have a ton of options, but at the end of the day, it'll be up to you to decide how you want to build your suspension. I probably have about 2.5-3k into my suspension at the moment, and my car handles like it's on rails, but still comfortable enough to drive on the street. The upgrade that made the biggest immediate difference for me was definitely the Konis, though my old shocks were completely blown out, so I couldn't tell you how they compare to stockers in good condition.

Last edited by LLCooLM495; May 13, 2026 at 05:46 AM. Reason: fixed typos
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Old May 12, 2026 | 09:03 AM
  #5  
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Engine: 5.7
Transmission: 700R
Re: Suspension upgrade

Originally Posted by LLCooLM495
Is this a street car, dedicated track car, or somewhere in between? I'll ramble a little bit and tell you about some of the options/ what I've done to the suspension on my (predominantly) street-driven car, that I definitely need to take to a track soon

There are tons of suspension/ handling parts available for thirdgens, all depends on what you want the car to do/ your budget. QA1 and Detroit Speed are probably the two best parts designers as far as innovation within the thirdgen space, though as you mentioned, very pricey. I've had good luck with both UMI and Founder's parts (wonder bar, upper strut mounts, rear LCA relocation brackets/ LCAs, panhard), though this can all add up as well; I've done my suspension upgrades piece by piece over the years to keep immediate cost down. If you're not looking to spend a ton of money, you'd probably do well with something simple like new upper strut mounts to start off (assuming your IROC has the factory wonder bar; if you DO NOT have a wonderbar, that should be your first upgrade). The stock strut mounts have rubber bushings, and they can deflect quite a bit. Aftermarket USMs have bearings in the top to get rid of that deflection, and help stiffen the front end feel up a fair bit.

If you already have the big sway bars from factory (35mm iirc for IROCs up front, 23 or 24mm rear), then you could just get some new poly bushings and end links and be in pretty good shape. The aftermarket sway bars are nice, but not all that different in size. Sure, chromemoly is an upgrade, but the stock sway bars do just fine if you aren't looking to set track records; new bushings help a ton, and are fairly cheap. Shocks also make a big difference in handling, and I've been quite happy with my Konis. They aren't exactly cheap, but as far as shocks/ struts, they're pretty much the best you can get without shelling out for coilovers. Koni has a sale every July, so get 'em in July if you have any interest in them. Think I paid $750 for my full set back in July 2023, vs the usual of close to a grand. KYB AGX struts are also pretty well regarded, but I've heard the rear shocks can be a bit harsh, even on the "softest" setting.

For springs, you can go as simple as Eibach lowering springs, or as fancy as somethin like Ground Control weight jacks (again, assuming no coilovers). I finally bit the bullet on GC weight jacks last year, and I've been super happy with how they changed the car. They folks at Ground Control will help you pick spring rates for the front and rear, depending on your motor/ what you want the car to do/ what shocks you're running and all, springs are included with the price of the weight jacks. The weight jacks also give you relatively easy height adjustment. If you do go for weight jacks, I'd recommend just getting the standard ones for the rear. I opted for the "upgraded" rear weight jacks, and while they are quite nice, I didn't realize that I'd have to cut out an access panel in the bottom of the driver's size spring perch. Not a big deal, and may not matter if you have a 9 bolt, but something to keep in mind.

If you're looking to stiffen the chassis, subframe connectors are gonna be what you want. They tie your front and rear subframes together so your car isn't held together by the floor pan (yay unibodies!), and I'm hoping to be able to get them soon. You'll want them welded in, which is what's been stopping me for the moment.... you could pair those with Alston's inner SFCs if you wanna get crazy, but most folks are more than happy with just the outer ones. From what I've heard from my thirdgen friends, the UMI SFCs are the best option for the outers (regular SFCs).

For a-arms and k-members, if you want to drive your car on the street, stock is honestly going to be your best option (unless you want to shell out big money for QA1/ Detroit Speed). There's a good bit of talk on this site about a-arms and k-members from other companies tending to crack with street driving, guess they weren't really designed to handle all the bumps and potholes. The stock stuff is actually quite beefy, and these are usually only replaced for weight savings/ extra engine bay space/ adjustability. If you want to replace your a-arm bushings, Global West's Del-a-Lums are going to be the best you can get. They replace the stock rubber bushings with a solid aluminum sleeve and a delrin bushing, which completely eliminates deflection on the a-arms. I put these in earlier this year, and they've been absolutely wonderful. Seen some anecdotes about them lasting well over 100k miles/ 20 years, Global West has been in the delrin bushing business for decades, and they have great customer service. They ARE a massive pain to install though, since they're so precisely machines, and you're gonna want to use a hydraulic press for them (or pay a shop to do it, which is what most folks do). For ball joints, avoid AC Delco, their ball joints are junk unfortunately. I had to pull my new ACD ball joints back out immediately because one wouldn't take grease (and ended up splitting in half), and the other wouldn't hold grease. I put in a pair of Mevotech Supremes, working great. Don't get any fancy low-friction ball joints if you plan to drive on the street, totally unnecessary on anything but a dedicated race car.

In summary, you can definitely get pretty significant results if you want to put in the time and money, but if you're just looking for sportier handling on the street, new bushings will go a long ways. Good cheap upgrades are gonna be the Founder's LCAs ($120 or so), UMI's LCA relocation brackets (about $80), and new bushings on your sway bars (about $70 including end links if you go poly). Shocks/ struts will help further with body roll and ride, along with springs. Upper strut mounts will help further with preventing deflection on the front struts, and give you more adjustability. You have a ton of options, but at the end of the day, it'll be up to you to decide how you want to build your suspension. I probably have about 2.5-3k into my suspension at the moment, and my car handles like it's on rails, but still comfortable enough to drive on the street. The upgrade that made the biggest immediate difference for me was definitely the Konis, though my old shocks were completely blown out, so I couldn't tell you how they compare to stockers in good condition.
Fantastic information!!! I installed some monroe struts on the front myself and im not happy with how it drives. I know items are worn bushings springs ect. Time to upgrade. I like where you are at, handles like a rail but decent enough to drive. Thats what im looking for. I dont mind spending money on QA1 or Detriot speed or anything else. The feedback is exactly what im looking for and it will help steering me in the direction. Getting information on what members did and how the car responded and over all thoughts....thanks again for the excellent break down.
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Old May 19, 2026 | 08:50 PM
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Re: Suspension upgrade

Has anyone installed the QA1 level 2 handling kit? Pricey at $7500....but you know how it can go......you get what you pay for. Anyways was looking for any feedback. Thank you!
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Old May 20, 2026 | 12:18 PM
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Re: Suspension upgrade

I would not even think about spending that much if this is a daily driver, or even just a weekend warrior.
Just do lower control arms, panhard bar, subframe connectors, springs and shocks/struts.
Do the wonderbar if you don't have one.
After that, maybe torque arm.
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Old May 20, 2026 | 03:14 PM
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Re: Suspension upgrade

Originally Posted by Manic Z
I would not even think about spending that much if this is a daily driver, or even just a weekend warrior.
Just do lower control arms, panhard bar, subframe connectors, springs and shocks/struts.
Do the wonderbar if you don't have one.
After that, maybe torque arm.
Everything is worn and my front left camber is too far in on top. Im just trying to figure out whats the best option to kind of just take care of all of it.......worn bushings, control arms....ect. its original other then the Monroes I just installed. I love my car as you all do so im not really worried about cost......its more of whats the better or best option......in my case trying to replace the whole suspension. I was wondering if anyone did install a QA1 or something similar.....Thanks for your advise.
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Old May 20, 2026 | 03:29 PM
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Re: Suspension upgrade

What I'd recommend is some decent new shocks, then go to some place like RockAuto and buy all new tie rod ends, ball joints, bushings, etc. from AC Delco. These cars handle and ride pretty great in stock form, but after 40+ years that stuff all degrades (even with low miles). Just doing a whole refresh to "stock" can make I night & day difference. Did this with mine last year, fantastic results. Granted, mine is just a weekend warrior.
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Old May 20, 2026 | 03:42 PM
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Re: Suspension upgrade

Originally Posted by RedLeader289
What I'd recommend is some decent new shocks, then go to some place like RockAuto and buy all new tie rod ends, ball joints, bushings, etc. from AC Delco. These cars handle and ride pretty great in stock form, but after 40+ years that stuff all degrades (even with low miles). Just doing a whole refresh to "stock" can make I night & day difference. Did this with mine last year, fantastic results. Granted, mine is just a weekend warrior.
Thank you, Im like you as far as weekend worrier driving it. Great info.
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Old May 23, 2026 | 07:01 PM
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Re: Suspension upgrade

Don't worry...
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