Rear shock question...

[MaSnaka]

I purchased a set of coil overs (Pro Shock brand) from CRII just before they went poof. Thinking they would know what I needed, I put all my faith in them. Parts were delivered and installed and have been on the car for some time. A mechanic had my car on the lift recently and noticed the rear end dropping so far the springs were well off their perches and mentioned it to me that that wasn't right and either I need straps to limit the drop or my shocks are too long. I have not noticed them to bottom out but they are a little springy on certain types of bumps in the road where I bounce up in my seat only to be held down by the seat belts. How can I determine if they are right or not? Part numbers? Or is there a method to figure it out? Thanks!

John

[onetrackrider]

MaSnaka PM sent.

[JAC]

I have the same setup and would like to know if it's right or not too.

[Double Venom]

I hate to ask silly questions, but you guys know you need to adjust them -no?
Cpteddies rear coils (he's a big guy) are adjusted 13-14 threads up from the bottom. Not adjusted or not adjusted properly the shock is doing all the work. The spring is just along for the ride.
DV

[tcrist]

Mine is the same way. They are also adjusted with 10-12 threads from the bottom. When I jack up the rear by the frame the spring comes off of the top perch. A street rod mechanic that I know says that the shock was about 2" too long.

Terry

[MaSnaka]

I didn't count the threads but it measures about 1 1/4" of threads exposed on the bottom. Ride height to the top of the rear wheel well is 27" from the ground.

John

[Hray]

Terry: that sounds to me like the shock is too tall for that spring. I have never seen a coil over set where there was slop with the spring when the shock was totally extended. Mind you I am not an expert on this, but I just have never seen this. For all the coil overs I have assembled i in most cases had to compress the spring just a little to be able to get them together. Maybe someone will tell us you have a new improved system here.

Ray

[Gunner]

Maybe I'm misunderstanding something here, but the thought that a kit manufacturer was shipping completely wrong suspension parts makes my hair stand on end.

[tcrist]

Gunner,
I agree, I only wish that was the only parts that they sent wrong, but it was not. My guess is that (for me at least) mine is a late 80's-early 90's car (before Don bought the company and might have made some changes) and they might have been sending me parts that were for the late 90's- early 00's cars. Who knows and no-one will ever find out as they are now out of business.

I realy never had any issues with Don directly. He actually even gave me parts that I was missing even though he did not sell me the my CR.

Terry

[HI Cobra]

I think I hit the sweet spot when I got mine in '99. I later heard horror
stories of pre '99 and then more later. I got a lot of odds and ends from Don
as time went on and he was always A+ to deal with. I, for one, am really sad
that things didn't work out for what ever reasons because he was always a
pleasure to deal with.

[Double Venom]

ET. AL,,
Lets stop the passing of bad info for one last time shall we!


ONE AND LAST TIME: Pay Attention!
The Kits did NOT change from the mid 80's to present day! Don DID NOT by any means ship wrong parts with the kit! But, IF you got parts from somewhere else including PRO Shocks down the road and the salesman only guessed at the parts do NOT blame CR's!

What changed in the very late 80's until Don took over was the guy that made the bodies for CR's- HENRY! Henry did OK but shall we say sloppy work. The KITS them self never changed*. Problem was HENRY bodies took more work (in the body shop) to get them right-but that was it! Don later switched fiberglass companies and the bodies were coming out nice!

While Don took over he did change the pedal box, wiring harness, floor pans, brakes etc., all in the name/engineering to make a better car!

REAR SHOCKS: What was called for was PRO SHOCk SM 600, rear springs were in the 250lb range, but easily changed per order! Max extension was 16-1/4", collapse is 10-1/2"s.

Depending on your individual set up the Springs may come off the perches when the car is picked up by the frame OR they may not! It ALL depends on how loose or tight you have your springs set. I.E., Cpteddie's, because I have set Ed's left rear Spring pretty tight it WILL stay in the perches when picked up by the frame while the right side-set a little "softer" will most likely come out of the perch when picked up. ALMOST always the spring will SELF-CENTER when the weight is re-applied.

1979 until 2004 (+/-) basically all the same kit with the exception of the above.

DV

[Gunner]

Originally Posted by Double Venom

Depending on your individual set up the Springs may come off the perches when the car is picked up by the frame OR they may not! It ALL depends on how loose or tight you have your springs set.

I know zilch about CR's and wouldn't say a word good or bad about them. But from the description in this thread, the CR-supplied rear coilovers were badly sized - a truly scary prospect, as not all of us are trained race mechanics and may not spot a serious problem in an "official" part.

As for the shocks extending past the coilover length... I politely call baloney. Recall, if you will, that the primary design flaw in the original Corvair was that the only thing limiting rear suspension travel was the shock, a job it was never meant to do. Under certain conditions, the swing axle could "jack" to the point where it damaged the shock, leaving the suspension jammed in a full-extension position.

That the CR suspension can travel further than the coilover spring supports makes me question the design. Maybe it's as good as any other Cobra's - but I'd sure as hell be out there checking geometry and hard stops before I drove mine again.

[Double Venom]

GUNNER,
APPLES and ORANGES! I am VERY familiar with the Corvair of yesteryear.
Baloney as you call it is BALONEY! POLITELY OR NOT! Corvairs problem (one of many!) was as you say with a Swing Arm rear suspension. Now give me one OEM car, any one that uses a coil over suspension that, not struts please, the shock can not extend past the coil if so designed!

So you know: Myself and Steve, (now retired) (part owner and engineer of PRO-SHOCKS) spent a good three days engineering this combination. I was just the Gopher he and the computer did all the work at SEMA the last time it was in Columbus. He also designed the Double Venoms suspension. QA-1's did the same thing, they make the ACR (Viper) racing suspension.

Good thing I like Baloney! Show me I am wrong and I will gladly eat your Baloney.

DV

[Gunner]

DV: *shrug*. I don't drive one. I don't care except in the general way that I don't want any of my brothers in snakehood driving a potentially dangerous design. The discussion above, starting with a description of a bad fit of CR-supplied parts, raises a lot of questions that should be resolved with something other than arm-waving and generalities about how three days of engineering time couldn't have had any mistakes in it.

I've been in several engineering fields and seen designs with multiple generations and years of service that had serious flaws going back to sketch one, not caught until someone asked the right question.

If you're familiar with the history of the Corvair, you'll recall GM's response to those who suggested there might be a flaw in the rear suspension design.

Maybe - just maybe, just a suggestion, I'm moving on now and you can ignore me if you like - maybe you should stop treating this as some kind of personal slam and take a fresh look at the machinery. Maybe you missed something. The evidence in this thread is, to me, at the very least worth a review. These are, after all, CR owners talking.

Gunner out.

[Double Venom]

Gunner,
If you knew me you would know I don't take any of this serious except "Safety" period.
I agree 1000 % with the adage " We've been doing it this way for years" doesn't 'hold a drop with me! That is why I asked if you had any concrete information on your point? I assure you proven wrong, and I have been many times I will be the FIRST person to change my replies or given information!

Re-read my post about supplied parts concerning this thread! I know at times the wrong part from what was asked for was shipped wrong but I never knew of any part that was designed for the car or built into the car that wasn't right.

Please think of it this way... If the shock was NOT capable of supporting the Rear End
then the spring would have to be "fixed" by some means, pockets, brackets,some way, right? Then I believe you would NOT have a rear independent adjustable rear end or suspension.

Fella I will never ignore your posts, most make people think or question a comment-which is a good thing.

No degrees, that why I went to the Pro's many times! But, I did almost three decades of Fatal Accident Reconstruction, Northwest Traffic Institute, OSP, CPD, ETC, Etc.
Safety in these cars is paramount-we cause enough of our own problems- we do not need any help wth poorly designed flaws!

DV-still learning!

OO0ps! See page 2!

[tcrist]

DV,
You have a personal e-mail.
Terry

[Double Venom]

Knew something was wrong with my last post- hanging head assuming too much again..

The FRONT suspension on a CR's can be set up easily for a adjustable suspension, BUT the front control arms CAN only travel so far possibly allowing the shock to come out of a perch if they are set up totally wrong! Point is the springs aren't fixed but the control arms are!

Then it comes to mind that hopefully GUNNER and I are discussing the same Apples!
Where as the "normal" rear end on a CR's Cobra is a fixed
/single axle rear end and not swing arms like FF uses, or Unique or even Kirkhams, or even the old Corvair!

DV

Two brothers, two Dads, one sister, one mother, one Uncle all worked in a supervisory position(s) at GM. Four yes 4 Corvairs in the family at one time, then they were replaced with Opel GT's! Man I loved that "Poor mans Corvette"!

[MaSnaka]

I bought them about 1 - 1 1/2 years before the CR shut down. Ordered them through Pete, who I believe was getting them through Don because he always had to check on my order through Don. They were on back order for months before I finally received them. I gave CR my credit card info when I ordered the parts, but the charges didn't go to my card until just before they shipped which I thought was proper.

I am going to check the application of these shocks to my car a little further and return to this thread. It might be a few days before I get to it though. Thanks for all the replies.

John

[JAC]

Thanks John, Keep us posted.

[jagrolet]

I think what happaned here is that the car was picked up on the rack on it's frame,the suspension is hanging in "full droop". In the type of rear suspension used on cr's, and 99 percent like it,they do not use check straps as droop limiters(the belief being,the car in most normal driving,would never have the suspension unloaded). On most open wheel cars i have driven,full IRS was the norm,and droop was an important condition as full load,as either one could cause coil bind,on one side,or both.
My geuss,is the spring length is incorrect,or to harsh(that is why it is so low on it's perch,to get a softer ride.) I would definately chech into the lengths and progressions to improve this,and that way,the spring is always loaded on the perch,rarely have i seen a coilover that you had to put at least a small amount of load on the spring,to engage the first threads of the perch.