Coil overs on a camaro sub?

[bowt1ed]

Anyone installed coil overs on their TF with 2nd Gen subframe? I originally had stock springs with 1 coil removed and had near desired ride height. During build (replacing bushings, ball joints) I replaced with new Hotchkis lowering springs, but ended up actually raising it around 5 inches. (?) Trying to decide whether to go back with cut original springs or adjustable coil overs. Looking for any insight or experience on it. Thanks.

Cheers, Jim

[Speedbumpauto]

I used Hiedt's control arms that are ready for the coil overs. There is a fair amount of ride height adjust-ability and the ride quality is good. I opted for the adjustable shocks also from Heidt. Best pic I have.

[bowt1ed]

Thanks Speedbump. I've been looking at the QA1 Pro Coil Adjustable. They claim to fit right in the stock control arms. Thinking the 350 lb would work for my SBC w/aluminum heads.

[BIGglaSS]

First, there is nothing wrong with the stock spring/shock style setup. As you have figured out, stock springs may not give the ride height that you want. There are thousands of different spring heights and rates available. But since this is no longer a stock application, it will involve trial and error to get it right. This is the cheapest option!

If you decide on coil over, FIRST mock up everything at ride height without shocks or springs installed. Then measure for shock size and travel. Call the manufacturer of your choice, and they will walk you through the correct parts and spring size! Why? Because there are a couple different ways to mount the subframe height in our trucks. Whether the clip is grafted in level with the truck frame, or the whole subframe is welded to the bottom of the truck frame. This alone is a 2” difference in ride height. Now add stock or drop spindles and there is another set of issues. This could make a difference whether you can use bolt-in Camaro coil overs, or have to custom order different shock/spring height.

I went with coil overs on my TF swap with Nova clip (Similar to 2nd gen Camaro). Initially I bought a Camaro coil over kit without doing any research. Sure, it bolted in, but the stance was sky-high. Another thing I did not like was the way the upper shock mount articulates. The bushing has to flex, and this puts stress on the upper shock mount. (Qa1, and Vi-king mount like this). Do some research on these kits. Many people have reported the upper studs bending or breaking!

This led me to do a lot of research on different ways to mount a coil over. As I soon discovered, there are MANY ways to do this. There is not one perfect solution for these swaps, and since it is a custom installation and ride height, you may have to do some trial and error. (and lots of $$$). I do not endorse or recommend any of the following products, that is for you to decide. I only post these products as some examples of what is available.



First order of business is the lower control arm mount. Using the stock lower control arms, there is not enough support for the lower shock mount to support the weight of your truck. The simple solution is to weld a 1/4” plate into the bottom of the cup.

The downfall of this style mount is the T-Bar is the weakest link. The lower shock must use a t-bar to mount to the cup. I had issues with different manufacturers are inconsistent in what size mounting hardware they use. The bigger the mounting bolt (3/8”), the thinner the t-bar is.
As I recall, Ridetech Tbar has more “meat” to it, and this is what I am using. The first TBar I bought, there were NO WAY I was going to use them, they were too thin.

The next option is to use a through bolt mount lower arm, something like this from Global West:

I think this is a better mounting option, since the lower shock must support the weight of the truck.

There are also perches that mount to the lower control arm so you can use a through mount in leu of a T-Bar. However, this will add an inch or two to the ride height.



Moving on to upper mounts. There are true coil overs, which have the spring cup mounted to the top of the shock. (Ridetech, Alston, & Aldan).

Each one of these have a different upper mounting system. Starting with most expensive, Alston uses a ball joint for the upper shock mount. Ridetech uses delron bushings that swivel. Aldan uses rubber bushings that must flex as the suspension articulates.

Or there are hybrid which use an open coil that seats into the spring pocket of the frame. (QA1, or Vi-King).

Again, on this setup, the upper shock stud must flex via a rubber bushing.

Now, if you’re bothered by the upper shock mount flex, that leaves you with a couple options. Alston, or Ridetech have articulating upper mounts, and both offer BOLT-IN solutions. Due to the height of the Alston ball joint, it compromises spring height. Meaning you use a shorter spring at a higher spring rate than the comparable Ridetech. If you have the skill to fabricate, you can cut out the upper spring pocket from the frame, and use eye mounts for the upper. Like this kit from Speedtech: http://www.speedtechperformance.com/...prod/prd57.htm I think this is the best upper mount solution. It also allows you to run a taller shock/spring combo for more travel and softer spring rate. However, it is not an EASY solution.


I ended up going with Ridetech. They look and feel like much higher quality than the first kit I bought. Their sales support set me up with HQ single adjustable stud mount coil overs. I can’t comment on the ride, because this truck isn’t on the road yet. Keep in mind, this is a Nova clip. To use a taller than Nova shock/spring I had to raise the upper mount to get more travel. With a Camaro clip, you would not need to do that. And, this is the best picture I have...


I hope this helps, and good luck!

[bowt1ed]

Wow, thanks for the feedback!

[Never enough]

The first thing that comes to mind is...did you replace the arm bushings with stock rubber ? If so, did you torque the thru bolts with it hanging in the air ? That will cause the front to sit higher. As an aside, did you clock the spring ends into their pockets ?
If urethane, I still leave the bolts slightly loose until the vehicle is sitting on the wheels. I grease them while hanging free and then I use 8x8 blocks of wood under the tires to get it resting on it's own weight and still have room to scoot under and torque the bolts.

If you go to coil overs, the T bar goes INSIDE the lower arm, NOT underneath as with original shocks. The 5/16 bolts are plenty strong enough to hold the T bar in place, as they are not there to bear the weight of the vehicle. If your lower arms have the nuts welded on the inside, you will need to remove them for the T bar to sit flat in the pocket.

As for issues with the shock top mount, I haven't seen any when the stud is mounted to the correct tightness to the bushings, whether rubber or urethane. That stud does rock back and forth some with the swing of the suspension travel arc, so it can't be tightened down too firmly, or mounted solid, or the stud could flex and snap. The stud doesn't bear the weight of the vehicle either, only the dampening forces, so it is intended to be loose enough to pivot without unnecessary looseness or binding.

Choosing the spring rate is the most difficult aspect of this swap, as I've found most recommendations are for too high of a rate and I can't get the vehicle down where I want it. The suggested spring rates seem to be for stock ride height and I can't turn the rings down low enough to drop it. I usually end up with the next lower rate spring and turn the adjustment rings up until the vehicle sits where I want. The ride quality is still good, BUT it will be firm, as that is what all this aftermarket stuff is about. Firm up the ride and eliminate the washy, swaying of stock suspension for better handling.

And after all this....BiglaSS is right, if you were almost happy with the cut original springs, it is FAR less expensive than going with all the other modifications. I have Hotchkis lowering springs in 2 of my cars and they did drop the approximate distance stated and ride just as well as the 2 cars with coil over conver$ion$....

[bowt1ed]

Guys, I appreciate the input. At this point I may just pick up a set of original 2nd gen springs, cut a coil, and then decide whether to add some drop spindles.

Thanks again, Jim

[Never enough]

Drop spindles can create clearance issues of their own.

Were the original cut coils still too high or low ? Trying to understand why you would buy another set of coils and cut them ?

[bowt1ed]

No, the "original" cut coils actually had a good stance. However, like everything else, they were over 35 years old and likely lost some of the original tension characteristics. I couldn't see rebuilding the subframe with new bushings and ball joints, blasting/powdercoating control arms, and not replacing the springs and shocks. I thought the "lowering springs" I got would keep the same stance, but that wasn't the case.

[reaper71]

Nice wright up.
I opted to "Z" my frame to get it as low as I wanted with keeping stock spring height I did however go with the QA1 coilovers and I also narrowed my arms for clearance for turning Project Orangepeel page 1 shows the steps.
The reason I did the Z is so I could still have full travel but get it slammed on the ground. The running boards sit 3" off the ground.

Mark...

[BIGglaSS]

Neverenough, a lot of good points that I left out. If you are going to stick with stock type springs, search around the nastyz28 forum for recommended spring rate/height. Moog has thousands of different springs/rates to get you close. If your clip is installed at the same height as a Camaro, stock type springs should work fine. At this point, I would stick to the stock style shock/spring package. Later, if you are not happy with the performance, or want more bling, then consider coil-over. Jumping into coil-overs is an expensive rabbit hole.

But, if you do...


Here's a few pictures of some issues I encountered on the coil over conversion. Take a look at this Tbar. After it is milled for 3/8 bolt, there is very little “meat” left for support. If I recall, it is a ½” bar, thus leaving only 1/16” fingers to support the weight of your truck. Off hand, I don't recall the size of the Ridetech bars, but they have significantly more material for support. (I don't have a picture)



Installed pic of hybrid coil over:

The shock mount hole is not centered with the spring pocket on Camaro/Nova clips. I had issues of the shock body making contact with the spring pocket. I had to trim the frame away for shock clearance. You can't trim much if using the hybrid coil-over because the frame still has to hold the spring.


Also, you need to know whether your clip is Camaro, or Nova. All the parts are interchangeable and the same, EXCEPT shocks! Nova has 1” shorter shock and less travel than the Camaro clip. Springs are the same. I have the Nova clip. I modified the upper mount to run a 4.1” Ridetech shock with 10” 550lb spring.

Ridetech has a spring calculator to get you close. Going to the Camaro forums, 550 is a popular rate for 10” spring. http://www.ridetech.com/tech/spring-rate-calculator/

If your clip is installed under the truck frame, there is no need for drop spindles. You should be able to get it down to a 6-7” rocker height by playing with spring rate/height. It is difficult to fit wide wheels and tires with drop spindles. The tie rods will hit the tire or the wheel with stock “off-the-shelf” offsets. To fit a wide wheel/tire and tuck it in the fender, you will need a 18” or greater wheel/tire, and lots of backspace. Too much backspace, and the tire will rub the frame and the wheel lip will hit the tie rod. Not enough, and it will rub the fender. I played around with tires and offsets to get the widest tire I could, tucked in the fender. I ended up with 18x8.5” and 225/40r18 tire. 18X8 with the correct offset and 235 tire should also fit, but will be close. 20” wheel should clear the tie rod.



This is as low as I can get with drop spindles, and keep the tires from rubbing the fenders. Rockers are approximately 6.5” from ground. My clip is installed level with truck frame. NOT z'd.




Any more questions, just ask. Got any pics of the clip install?

[bowt1ed]

Here's the best shots of the clip I have on hand. It was not z'd, but straight installed. The teal pics are before I started breaking it down this time (orig coils w/1 coil cut), the others are with the new Hotchkis lowering springs.

[bowt1ed]

BTW, I won't be running those tires/wheels - just some old rollers. I plan on 18's around or perhaps 20's in rear.

[BIGglaSS]

Good looking truck. You're on the right track. If you can't get the stance right with what you have, then look into coil-overs and/or drop spindles. With 18's you can custom offset a little bit to tuck in the tires. You should be able to get some Moog springs for an affordable price. It will settle down a couple more inches with the sheetmetal and doors installed.

[bowt1ed]

Still have a ways to go before its rolling again..., but it's now official!

Cheers, Jim