I am considering going to a coil over conversion on my '63 Vert. I have stock upper and lower control arms. I have a 350 with aluminum heads and intake, aluminum radiator and Vintage Air A/C. Currently I have '67 big block A/C springs which were added by the previous owner to lift the front high enough for the 17X8 rims with P245/45R17 tires. (Still didn't clear if the suspension compressed.) I have just changed to Foose legend 17X7 with P225/60R17 tires and want to get my front end out of the sky. I was hoping a coil over conversion would allow me to fine tune the ride height given that my front end is likely lighter than stock with the aluminum heads/intake. Any input on brand (Van Steele, Speed Direct, VB & P, Jim Meyers etc) and/or spring choice? Am I just better off selcting small block, non-AC spings and adding QA1 adjustable shocks. Finally, for a street driven car, would the single adjustable shocks be fine or would the double adjustable be significantly better? Any input to any of these issues would be appreciated.

 

Um....................the 1963 Corvette HAS "coil over" suspension....but it is not "adjustable".

 

Sure they are... all you need is a cut off wheel, LOL.. Just make sure you don't cut to much.

 

I'm not qualified to discuss coil-overs or adjustable shocks,
but I'm interested in your idea of small block, non-AC springs.

I'd guess the addition of the Vintage Air A/C will balance out the aluminum heads and intake and put you pretty close to a stock base small block.

Now... is stock ride/handling what you're looking for?

I went in a little different direction with my '67.
It's a big block with a fair amount of changes so I'd guess it's about 100 pounds lighter than a normal big block.
But I went with big block A/C springs thinking I'd get better handling.

I forget the rate of my springs but they're lighter than the 460 pound springs from VBP and a lot lighter than the F41 springs.

Just my weird idea...

In terms of ride height, if you think about the spring rates and how much even 100 pounds compresses the springs I don't think the weight matters much at all compared to the spring design height.

 

63 Corvette, yes, I am aware that the '63 Corvette technically does have a "coil over" suspension. I should have been more precise in what I was referring to. "Pure" coil overs, to invent a term, would refer to shocks which completely house both the upper and lower ends of the spring suspending the vehicle. I find this idea unsatisfactory since the upper and lower shock mounts were never designed to carry this degree of load. "Semi" coil overs, again, to coin a term, would be what is commonly available where the top of the spring is located in the stock frame spring bucket (good) while the bottom of the spring is captured by an adjustable pad on the shock (potentially not so good). This, of course, does submit the lower shock mount to more stress than was initially intended. Indeed, there appears to have been some controversy on this forum as to whether stock control arms can withstand this or if some form of reinforcements are needed (this was one reason for starting this thread...to see what others have experienced in this regard). Hope that clarifies.

 

Steve, thanks for your comments. You make an interesting and important note about design height of the spring. The '63 Corvette assembly manual has measurements of "stock" ride heights front and rear which I am sure would be achievable with the stock spring designs for each application. In fact, I would assume that the various spring options available were all designed to net the same ride height depending on vehicle options/engine choices. I like the idea of an adjustable shock (I tend to gravitate to the QA1) to be able to match whatever spring I ultimately choose. Regarding final installed height, I would imagine this would be dependent on the weight of your vehicle which is why I was considering a 327, non-AC spring if I don't go with the "semi" coil overs.

 

I would not run coil-overs without SIGNIFICANT reinforcement of the upper shock mount and an entirely new lower shock mount, or specifically designed lower A-arm. You'd be putting some small welds and small fasteners directly in tension, in the "load path" for all the suspension loads.

I'd suggest accepting the ride height from the front springs and leveling the car up using trick bolts for the rear spring...

Harry

 

I used the Van Steel a-arms with the coil overs on my 67 small block.. It does allow you to adjust the height, however they are hard to turn when adjusting. Some coil-overs have a bearing at the base that makes it easy to turn for the adjustment, but these do not have them. I had a very hard time adjusting them.

VG

 

Why? The coil is still supported by the upper A-arm and not the upper shock mount. The only thing the upper shock mount does is support the top of the shock. The only thing you are changing is the coil/shock mount on the lower a-arm to mount on the top of the arm. You put on a plate with two bolts in COMPRESSION on top of the lower arm.

Better look at it again Harry.

 

With "pure" coilovers (see definition above) the upper shock mount would have significantly increased stress. I am actually most interested in "semi" coil overs where the upper spring seats in the existing frame spring pocket, therefore no increase stress to the upper shock mount. I saw on the forum that some members had fabricated a mounting plate to help spread the stresses to the lower a-arm. I am surprised these are sold for both Camaros and Corvettes with use of the stock lower control arms. V B & P informed me that these could not be used with their lower control arms. I was considering using V B & P lower control arms without the transverse spring and use "semi" coil overs but was told by them that that is a no go. Speed Direct also mentions on their web cite that the QA1 "semi" coil over springs no longer fit in the stock corvette spring pocket. They seem to have engineered their own springs for this use. Also, Speed Direct in the past mentioned that they were working on an aluminum lower control arm. I wonder if this will be designed with the stregth for a "semi" coil over to bolt in. Seems like there is a bit of an unmet need here that would be a popular upgrade if available. Some form of spacer/converter to use the new QA1 spring in the stock chassis would be good as well.

 

standard coils should be 13 1/2 inches long you probably have 17" coils in there right now, i had the same in my car so removed the coils and cut 2 rings off the top, gave me a perfect ride height and i run 15 X 7" rallys with 225 X 15 Michelins, no fitment issues on my drum brake car

 

??? the top of the stock coil spring isn't supported by the upper a-frame, it sits in the spring tower (which is the same as the upper shock mount). nothing is attached to the upper a-frame except the upper ball joint

Bill

 

All: So I took a look at the Semi-coil over setup offered by VBP. Still don't like the load path thru the lower shock mount bolts. I do get it though on the upper spring using the spring pocket not the shock mount.

Harry

 

Sorry, you're right, I confused the spring pocket with the inside of the a-arm. But the coilover still is not supported by the upper shock mount.

 

a true coilover is support by both upper and lower shock mounts, a semi-coilover has the top of the coil sitting in the spring tower like a conventional shock/spring arrangement. the bottom of the coil is supported by the shock body itself and then the shock/coil is supported by the lower shock mount/a-frame.

semi-coilover



coilover



Bill

 

Thanks Bill. I have the SEMI coilover setup and that's what I figured the OP was asking about. My bad.

 

Thanks for the responses guys. The pics better demonstrate my prior definitions of "semi" coilovers. As was noted above, one pathway is to trim the coils I have to get the desired ride height and then upgrade to shocks with adjustable valving. With this, I would consider the QA1 double vs single adjustable shocks. Again, for a street driven car, is there a significant advantage to the dual adjustable shocks?

 

I vouch for coil overs. I have tried pretty much every suspension set up available for C2/C3 cars and after I installed coil overs in all four corners and big sway bars I knew I had finally found what I'd been looking for. With the Bilstein coil overs I get very good ride, not cadillac but really nice. I got the ride height right where I wanted it and with the big sway bars the car handles just great!

 

What coilovers do you have at the back of your car I didn't realize they had coilovers for the rear.

 

I've got Bilsteins all around. It's a kit made by a German company in Europe. YOu'll need to weld new brackets to your trailing arms.



Old picture of the mock up.