1970 Camaro Tri-4 bar issue

[TBART70]

I say the bushings got damaged because they are poly, and thus weren't designed to articulate. I bet the suspension moves a lot smoother now with the johnny joints...

Andrew

It seems to be smooth. Lowered it half inch, shocks set 12 clicks back from full stiff. I put the lower shock mount in the middle hole and used the spring to adjust ride height. Left and right spring preload is still different. Car is level. Frame was jig welded from morrison. Not sure what is going on there.

Drove it today, seems better. Tires are definitely hard, older than I thought.

[Jon Clough]

Interesting thread and responses. I bought a AM rear triangulated 4 bar back in 2011 and am finally getting to the point (just retired) where I am starting the installation. It would be great to talk with you about the challenges you faced with its installation.
I need to go check out the parts they sold me now. Hope you get it sorted out.

[TBART70]

Did you buy a welded frame clip? I am curious what you have.

[TBART70]

Drove it today, still hopped. Dropped pressure to 30 psi. Should I make the shocks softer?

[Rod]

Drove it today, still hopped. Dropped pressure to 30 psi. Should I make the shocks softer?

it will wheel hop because no geometry points were changed, lower links need to be parallel with the ground (level) at your desired ride height...that's a start

[TBART70]

Should I put in a stiffer spring?
Pic of front coilovers. Not much height adjustment left.

Also still need to work on the rear.

[Rod]

Should I put in a stiffer spring?
Pic of front coilovers. Not much height adjustment left.

Also still need to work on the rear.

spring doesn't look compressed to much I think you need a longer spring, what do you have now?

[TheJDMan]

Should I put in a stiffer spring?
Pic of front coilovers. Not much height adjustment left.

Also still need to work on the rear.

Was that photo taken with the weight on or off the suspension? Either way, I agree with Rod that you likely need a longer spring.

[andrewb70]

Measure the total shock height with the suspension fully loaded. This will tell you how much compression and rebound travel you have with the shock.

Andrew

[Josh@Ridetech]

Do you have the part numbers of what front coilover parts you're using?

[TBART70]

14 inch center to center loaded. They came with the speedtech front suspension. I can't find invoice. I believe 10 inch spring.

[Josh@Ridetech]

14 inch center to center loaded. They came with the speedtech front suspension. I can't find invoice. I believe 10 inch spring.

If that's the perfect mid-travel length, you have a 5.2" stroke shock. You can verify that for sure by jacking the car up and letting the shock fully extend (you should see ~16.5"). That shock typically uses a 12" free length spring but you could run a drop cap, to help push the spring farther down on the shock, with a 10" spring if you aren't already. The way you have it set up now will work fine as long as you're driving the shock at mid-travel but it is always nice to have some adjustment. Does the upper retainer look like this one in the link below?

https://www.ridetech.com/products/co...-retainer-cup/

[TBART70]

Sorry got side tracked for a few months.

I think I have the standard caps on the front coils.

Have not driven it in two months.

I want to start to figure some of this stuff out, so I can work on it over the winter.

Thanks for the help.

[marolf101x]

Just to clarify this a bit as I seem to get a lot of people freaking out when they get near the ends of the threads. . .
If you notice the threads do not go all the way to the top of the shock. This was done for two purposes:
1-we need a smooth area to seal the air spring when the shock is used as a shockwave (shockwave and coil over use the same shock)
2-this allowed me to place the "stopping point" of the threads wherever I wanted, so I chose a location that would not allow the spring to coil bind

Hyperco springs typically reach coil bind when they are compressed to 80% of free length. So I looked at the heaviest spring I thought a street car would use, looked at the length, took 80% of free length and set the thread stopping point a little lower than than.

What does this mean?
-If you have the shock set near mid travel at ride height,
-and the spring is holding the car at the desired ride height,
-and you have standard "flat" caps, (the drop caps can make the spring bind, but typically not an issue)
-the coil spring will not bind.
-so it's ok and will work fine. . . . It may look a little strange, but it's perfectly fine.

Changing to a longer spring of the same rate is only aesthetic. . .the rate is still the same, the preload (if any) will still be the same. . .everything is the same except you covered more of the shock body.

Make sense?

[TBART70]

Yes it makes sense, thanks.

Question, how would you know if the car needed heavier springs, I think I have 650 lb springs. Aluminum head BBC Bowtie block. A lot of stuff, A/C, Vacuum pump, Heavy hood. Just thinking out loud.

Car drove decent today, although I did not launch it to see about wheel hop. It handles pretty well. I know it could be better if I lower the car.

[79T/Aman]

Yes it makes sense, thanks.

Question, how would you know if the car needed heavier springs, I think I have 650 lb springs. Aluminum head BBC Bowtie block. A lot of stuff, A/C, Vacuum pump, Heavy hood. Just thinking out loud.

Car drove decent today, although I did not launch it to see about wheel hop. It handles pretty well. I know it could be better if I lower the car.

My 2 cents, lowering the car will not necessarily make it handle better, lower center of gravity may help but the changes in roll centers and roll couple that come with it could far outweigh the benefit of lowering the car another fraction of an inch, this is not to say that lowering it further may not improve the geometry (highly unlikely) but without knowing what your starting point is and what the geometry of the suspension is it's just for esthetics.

[marolf101x]

How do you know if you need new springs?
If the adjuster is topped out and the car is still not at ride height.
If you drive the car and it bottoms out all the time.
Or if you want a different spring frequency, or wheel rate.

[TBART70]

My 2 cents, lowering the car will not necessarily make it handle better, lower center of gravity may help but the changes in roll centers and roll couple that come with it could far outweigh the benefit of lowering the car another fraction of an inch, this is not to say that lowering it further may not improve the geometry (highly unlikely) but without knowing what your starting point is and what the geometry of the suspension is it's just for esthetics.

I understand what you mean. I was referring mostly to the rear suspension, lowering the rear of the car would put the bars where they were designed to be. (Is that ideal? I don't know, Art Morrison designed it). As for the front, I don't know what optimal ride height should be, I never asked Speed Tech. That being said, the front is where it is because of header to ground clearance and the rear is set so it is level or slightly higher than the front( purely aesthetic ). Although I think I could only go down an inch in the front anyway, disregarding the header issue. The rear I think would need to go down at least an inch and a half to two inches to make the lower rear bar level with the ground. So back to the drawing board and decide how I am going to go about it and what to do about the headers.

[TBART70]

I want to start to address this. I might get a chance to drive it this weekend to see how it is before I make any changes, or take things apart. I will take out the front coilovers, I will measure before I take them out at ride height. Then when they are out. I still think the front needs more spring. Would another 50 lb. spring make that much of a difference? Based on the scaled weights, do you think it needs more front spring?

The rear, I think I am going to make new lower control arm front brackets, to get the bars more parallel to the ground. Again I know not doing the uppers is not ideal so........

I am also going to look at the headers and see what I can do, no one makes a set with better ground clearance, other than going custom or building them myself.

Does anyone know of someone in Northern NJ that can make a set of headers?

I would even go with mid length if I could I could find a set that has 2" or even 2 1/8" primary. I have not found any yet.

Again thanks for the input. Hopefully it helps me and also helps others before and after they start there projects.

[TBART70]

I have a 10" front spring at 600 lb./ in. rate. Should I go 650 or 700.? What about 12"? Front needs to come up a bit, and it did seem to want to bottom out.

I started modifying rear suspension, I started to drop the front of the lower bars.