I got the ground control systems coilover kit for my '88 coupe, and it has the wrong springs, and/or I told the shop wrong. I told them to remove the spring perches per Fieroguru's writeup, but it turns out through more research they should've just trimmed them down. So, time for new struts or to replace the springs with something that'll work. They're 7" springs. I'm thinking 10 or 12" springs will fix the issue?

I don't understand spring rate. The springs I got from ground control, are 400 lbs spring rate. That's per inch right? So if I go up to 12" springs what spring rate do I need? Anyone else deal with these kind of issues with the ground control kit?

Here's a picture of what is happening:



I see springs @ Summit Racing and I could go pick them up tomorrow.

Spring rate refers to how many pounds it takes to compress the spring one inch. Has nothing to do with spring length.

Also, you may see two different ratings;

A) Actual spring rate, which would be equal to what a Strut-type suspension sees (The Fiero rear suspension)

B) The spring rate through the suspension geometry- The front springs on the Fiero mount at (Approx') 60% of the A-arms length, so the actual spring rate is reduced to what the car sees (at the end of the A-arm)

Fieroguru on here supplies all the components you need for a coil-over conversion- including springs- I would talk to him if I were you.

[This message has been edited by cvxjet (edited 02-20-2023).]

Does the car bottom out right now if you attempt to put its weight on the tires?

You could keep the spring rate where it is... how did you choose the spring rate? Is it a good spring rate for your use?

If (temporarily) you can make some wood blocks as spacers for the springs, and you can get the car to the ride height you like (with the threaded adjuster in a good position, not at the end of the threads), then your new springs (assuming you stay with 400 lb/in) should be longer than your current springs by the amount of the spacer thickness.

quote Originally posted by cvxjet: Fieroguru on here supplies all the components you need for a coil-over conversion- including springs- I would talk to him if I were you.

Buy from vendor A, ask for support from vendor B?

Seems like it would be more logical to ask for help from vendor A, rather than bother vendor B who didn't get a cent from the transaction.

[This message has been edited by pmbrunelle (edited 02-20-2023).]

quote Originally posted by pmbrunelle: Does the car bottom out right now if you attempt to put its weight on the tires? You could keep the spring rate where it is... how did you choose the spring rate? Is it a good spring rate for your use? If (temporarily) you can make some wood blocks as spacers for the springs, and you can get the car to the ride height you like (with the threaded adjuster in a good position, not at the end of the threads), then your new springs (assuming you stay with 400 lb/in) should be longer than your current springs by the amount of the spacer thickness. Buy from vendor A, ask for support from vendor B? Seems like it would be more logical to ask for help from vendor A, rather than bother vendor B who didn't get a cent from the transaction.

Does it bottom out? It bottoms out just sitting there in the shop. There definitely isn't enough spring.

How'd I choose? Forum search. Most people on coilovers here seem to run 300-400 lbs, and on the higher end if you've got an engine swap. Car has a 3800SC. What I read today also indicated I need springs for the front or else the handling will be off, they're only 150-200 up front stock?

Well, fieroguru is an expert on this and made a very good write-up on what he does with his kits for DIY and ships out good kits. I talked to him and he said it'd be 2 weeks until shipping, and it'd probably be another week for it to arrive. To me that's the backup plan right now is to get the stage 3 of his kit, the struts I have are cut to use with his kit. It wasn't until I did more digging with the search today that I found a thread on the ground control kit I got that said not to remove the spring perches but to just cut them down, so I instructed the shop wrong.

Right now the car is at the shop, and I have 2 options:

A. Figure out the springs I need and go get them from Summit tomorrow, get them to the shop and they can complete the coilovers.

B. Buy from fieroguru and wait 2-3 weeks. I'll have to go get the car with the old struts/springs/wheels/tires on it and go back to get things installed later.

I'm looking at 2.5" ID 400-lb 12" springs on the summit racing website. I think that'd do it. I wasn't planning on lowering the car at all and haven't gotten front springs. Forum search says I should get equal springs for front and rear on this car, so 400? I was hoping to find 350 lbs. It has a 3800sc though so 400? I'm pretty sure the eibach springs ground control sent are 2.5" ID but I'm waiting on that measurement from the shop tomorrow.

[This message has been edited by sdgdf (edited 02-20-2023).]

quote Originally posted by sdgdf: I'm looking at 2.5" ID 400-lb 12" springs on the summit racing website. I think that'd do it. I wasn't planning on lowering the car at all and haven't gotten front springs.

I think that 10" would definitely be too short.

12" sounds like it might work.

Seeing as the threads of the Ground Control sleeve are pretty down low on the strut, I'm not sure if you can have "no lowering at all" with a 12" spring. I'm thinking that maybe you need a 14" spring, if you want stock ride height. But I'm not sure.

I bought "guru's" kit. 12" springs. I told him what I had, and what I was doing, including the 3.4 DOHC swap. He suggested 250# springs.
It can be lowered from stock with that exact kit. Mine is as low as I'd pretty much ever want to go with it. (2-3 fingers between the tire and the wheel well opening.
Here are some pics of the assembly. Before and after.

This was what I removed from the car. These were 88 front springs adapted to the rear.
I decided to do "guru's" coilovers because I have plans for the car, and also needed the shorter springs for my GT. Purely cosmetic.


This is the strut with the perch and all the other stuff removed. Painted with rust converter/primer.


This is the assembled coilover and strut, ready to go back into the car. After I set the car on the ground, and drove it to allow everything to settle, I ended up dropping it about another 3/4". (There are calibrations on the sleeve. Made it very easy.) It's essentially the same height that it was before I started, which is what I wanted.


Ride height. It's maybe actually just a "tick" lower than this, now, but that's okay.

[This message has been edited by Raydar (edited 02-20-2023).]

At a 400 lb/in spring rate, you will want a 10" spring.

quote Originally posted by fieroguru: At a 400 lb/in spring rate, you will want a 10" spring.

With your kit?

quote Originally posted by sdgdf: Looking at these: https://www.summitracing.co...rts/eib-14002500300s they have them in stock at summit racing and can ship out tomorrow. Either that or 12" and they'd probably be at the limit of the threads on the sleeve.

The spring rate describes how much the spring sags once the weight of the car is applied, relative to its free length. The spring rate also determines how stiff the ride is. I think that with 300 lb/in springs, you should go to 14" springs.

quote Originally posted by sdgdf: Also what's the ID and length of the stock 88 front springs? I can get some eibachs at summit? 300 lb/in equal front and back or no?

The stock front springs are not "standard coilover format" that can be easily replaced with aftermarket parts.

Probably you should take some time to research what you want to do with the front, rather than make a rushed decision while the car is stuck at the shop.

[This message has been edited by pmbrunelle (edited 02-20-2023).]

quote Originally posted by sdgdf: How long are your sleeves, like 6-7"? Mine from GC look like only 4"? I'm thinking pmbrunelle might be right and I need like 14" springs to have any adjustment range on the sleeve. And I'm thinking of stepping down to 300 lb/in. Looking at these: https://www.summitracing.co...rts/eib-14002500300s they have them in stock at summit racing and can ship out tomorrow. Either that or 12" and they'd probably be at the limit of the threads on the sleeve. Also what's the ID and length of the stock 88 front springs? I can get some eibachs at summit? 300 lb/in equal front and back or no?

My sleeves are ~6-7 inches. Just a guesstimate. I didn't measure. Paul will be able to answer that.
I was kind of curious why you were doing 400# springs, but a 3800 with an automatic is heavy, so...

Look at my assembled strut. Picture the adjuster cranked nearer the knuckle by ~3/4" (which is where I adjusted it after that pic was taken.) Not a lot of adjustment left before it bottoms out.
I think 14" springs might be too long for you. OTOH, the 4" sleeves might have all the adjustment you will need. Again, I'll bow to Paul's knowledge and experience.

My 88 springs were shortened by exactly one coil. The front ones, and the ones I installed on the rear. I couldn't tell you what the length is, either stock or modded, though.
I will mention that, at the "shortened" length (for the rear) I was able to install the "top hats" by pressing down manually and starting the nut on to the strut. I did not need a spring compressor. There was a little bit of pressure, but not much.

[This message has been edited by Raydar (edited 02-20-2023).]

quote Originally posted by fieroguru: At a 400 lb/in spring rate, you will want a 10" spring.

Ok I found it but I lost it in the 2 dozen threads I have open, how did you achieve 575 lb/in spring rate on the front of your car? And I've read a lot of threads, some say equal rate front and rear, but stock is higher in the front, and your setup is higher in the front (575 and 400?). So go higher in the front.

I have the same ground control kit. They're meant to fit right on to the stock/'stock style' struts. That's why its called a 'coilover conversion kit', because they convert your existing stock struts into coilovers.

Anyways, to salvage the struts you've had the perches cut off of, you could get some exhaust tubing to sandwich between the threaded sleeve and the top of the lower mount bracket. You can see here I did something similar but only to raise the threaded sleeve up about an inch. Tough to see but beneath the sleeve there is some exhaust tube painted red.

Or you could get a threaded sleeve that is way longer. They are all pretty universal but find one the same diameter and same thread pitch and it will work. Lots of Honda civic guys use these things should be lots of them around on ebay etc. If I were to guess an 8-10" sleeve would be ideal

[This message has been edited by greenturnedblue (edited 02-21-2023).]

quote Originally posted by sdgdf: With your kit?

With your kit or my kit it doesn't really matter. My sleeves are 4 3/4" tall, but when customers ask for springs stiffer than 350lb/in, then I cut the unthreaded portion of the sleeve off the bottom to increase the lower range.

Part of the service for anyone that buys my coilovers is we review the specific details of your application, what you are looking for from the kit, and I help guide you down a path to the spring rate that will work well for your specific setup and goals. This takes time and is more expensive, but avoids many of the issues you are having right now.

If you want to fix your car fast:
400 lb/in - buy a 10" spring
350 lb/in - buy a 12" spring
300 lb/in - buy a 12" spring
250 lb/in - buy a 12" spring

Adding a section of exhaust tubing to raise the sleeve also works.

You really need to do your homework on this. Throwing parts at the suspension without thought may not work out. Fieroguru pretty much spells it out for what you need, I would take his advice. Everything needs to be taken into consideration when doing this, ride height, type of driving, motor combo etc....

I have QA1 springs on all four corners of my car. I am running 450lb springs in the front and 350lb springs in the rear. I am using a 10" high travel spring in the rear and a 7" adjustment sleeve.

BTW, you are not far from a lot of Georgia Fiero club members.

quote Originally posted by fieroguru: With your kit or my kit it doesn't really matter. My sleeves are 4 3/4" tall, but when customers ask for springs stiffer than 350lb/in, then I cut the unthreaded portion of the sleeve off the bottom to increase the lower range. Part of the service for anyone that buys my coilovers is we review the specific details of your application, what you are looking for from the kit, and I help guide you down a path to the spring rate that will work well for your specific setup and goals. This takes time and is more expensive, but avoids many of the issues you are having right now. If you want to fix your car fast: 400 lb/in - buy a 10" spring 350 lb/in - buy a 12" spring 300 lb/in - buy a 12" spring 250 lb/in - buy a 12" spring Adding a section of exhaust tubing to raise the sleeve also works.

Thanks, this sounds like the plan, I've found springs on summit that fit the bill, aiming for 250-300 lb/in in back with a 12" spring. The exhaust tubing acting as a spacer sounds good too to get the right fit.

I'm aiming for 350-400 in front, the car won't handle right with 300 lb/in in back and the stock front springs? The factory setup and your personal setup the front has a higher spring rate? Seems like a good idea to maintain that? In the moog catalog I found some springs I really like, moog-2278. I think you mentioned in a thread (like this: https://www.fiero.nl/forum/...m2/HTML/139057.html, can't find the exact thread right now) that moog 6556 would work on a Fiero, and the 2278 is similar but 3" shorter and 435 lb/in.

So 435 front 300 rear. No cutting springs. Have to modify the front bump stops because this drops the 88 front by 2"? Then with the adjusters in the back I can get the back lowered the same as the front and level.

Either that or just go 250 lb/in in back and keep the front stock.

[This message has been edited by sdgdf (edited 02-21-2023).]

I've gotta ask... What do you plan on doing with your car? Just a fun driver? Or are you going to autocross or track it?
I don't know that I would go with the high spring rates, unless you really need to.
My car has a conglomeration of stuff, with nothing that stiff.
The V8 car has 86 GT front springs in the front, cut by 1.25 coils, and 88 front springs in the rear, cut by one coil. It rides fine, and handles fine with Monroe shocks and struts. Has poly everywhere.
The 88 coupe has Guru's coilovers in the rear - also on Monroes (pain in the azz to convert Monroe's, but it's what I had) and stock springs in the front, also cut by one coil. Also has poly everywhere, except the trailing links (by design.)
If I ever track anything, it'll be the coupe, after I swap it. If it needs to be stiffer, I'll deal with it later.

Paul was quite helpful with me. Took the time to answer a bunch of "rookie" questions that I had. Hard to beat all that experience.
Also, keep in mind that he's done a bunch of work to his car, over the years, to make those stiff springs play nicely with everything else. It's far from stock, even ignoring the LS.

quote Originally posted by Raydar: I've gotta ask... What do you plan on doing with your car? Just a fun driver? Or are you going to autocross or track it? I don't know that I would go with the high spring rates, unless you really need to. My car has a conglomeration of stuff, with nothing that stiff. The V8 car has 86 GT front springs in the front, cut by 1.25 coils, and 88 front springs in the rear, cut by one coil. It rides fine, and handles fine with Monroe shocks and struts. Has poly everywhere. The 88 coupe has Guru's coilovers in the rear - also on Monroes (pain in the azz to convert Monroe's, but it's what I had) and stock springs in the front, also cut by one coil. Also has poly everywhere, except the trailing links (by design.) If I ever track anything, it'll be the coupe, after I swap it. If it needs to be stiffer, I'll deal with it later. Paul was quite helpful with me. Took the time to answer a bunch of "rookie" questions that I had. Hard to beat all that experience. Also, keep in mind that he's done a bunch of work to his car, over the years, to make those stiff springs play nicely with everything else. It's far from stock, even ignoring the LS.

Mountain driving, autox, hpde at road atlanta, it’s not going to be a daily driver so I expect it to ride rough, poly might squeak a bit and my pads might make noise and dust. Fieroguru runs 575/400 springs which is too much for me. 435/300 might be alright. The other front springs I found in the moog catalog are like 375 so I could do 375/300 or 375/250. I want it to handle well and in a thread I found using the search someone said they felt too much body roll with stock’ish kinda spring rates.

Surprised today when I went by the shop and they were able to fit my wheels/tires without them hitting the spring perches. 255s on 8.75” wide wheels. So I might not even need coilovers? Still want to move forward, but maybe go with fierogurus stage 3 kit? Need something for the front springs to balance with the back too if I do that.

[This message has been edited by sdgdf (edited 02-21-2023).]

quote Originally posted by sdgdf: Fieroguru runs 575/400 springs which is too much for me.

Just for the record, after I upgraded to the addco sway bars front/rear I switched back to stock 88 front springs with 3/4 coil removed and 250 lb/in rear coilovers and started to experiment with bump springs vs. bump stops. I want close to stock ride for about 1" of travel then let it firm up substantially when the lateral loads increase.

quote Originally posted by fieroguru: Just for the record, after I upgraded to the addco sway bars front/rear I switched back to stock 88 front springs with 3/4 coil removed and 250 lb/in rear coilovers and started to experiment with bump springs vs. bump stops. I want close to stock ride for about 1" of travel then let it firm up substantially when the lateral loads increase.

Sounds good! And the next step to all this, getting good stiff handling and retaining driveability. I just had a lot of work done on the car so I’m in the stage where I’m trying to wrap this part up, springs can finish this up as it is. 200s for spring rate might be ok. I don’t mind how the car handles stock.

Here’s how it looks so far:





Sticks out a little but I don’t mind to fit this much tire under it. Somehow the 255s fit without hitting the struts without coilovers. The 33mm offset?

And I need to lower the front.

[This message has been edited by sdgdf (edited 02-23-2023).]

Just starting my research on suspension upgrades for my new Fiero. Planned on spending hours digging through dozens of threads. This is the first one on the list. when you search "coilovers" in this forum.

Now I know I can go back to looking at wheels and boobies and just get in touch with Guru when I am ready to buy.

I am loving this place.

[This message has been edited by fredtoast (edited 06-09-2023).]

quote Originally posted by fredtoast: ... Now I know I can go back to looking at wheels and boobies and just get in touch with Guru when I am ready to buy.

Sounds like a plan, on all counts.

All kidding aside, Guru has some nice stuff. All top shelf.
If you want to do tubular front control arms, or an LS4, check out Gary Pickardt, in addition.