65-69 Suspension on 64?

[troy.w]

Will the late model independent suspension work in a 64?

[joelsplace]

Yes but it is a ton of work.

[troy.w]

What is another way to improve the 64 suspension?

[bbodie52]

Mon Jul 20, 2015 3:31 pm

...Has anyone here successfully done an Independent rear suspension (IRS) conversion for a 1st gen Corvair?

The rear suspension design used in the mid-1960's Corvette Stingray was adapted to fit the 1965-1969 Corvair, to replace the somewhat controversial swing axle design that was originally copied from the Volkswagen beetle in the 1960-1964 Corvair. The Corvette utilized a transverse leaf spring (I assume because of the fiberglass body), while the Corvair used a similar design but supported the car with coil springs.

Here is a link to a Corvair Forum thread that shows an Early Model Corvair that has been modified to install a late model Corvair rear suspension. But this is not a common or simple modification!

http://www.corvairforum.com/forum/viewt ... =176&t=349

You can see that the rear suspension mounting was entirely different in the late model Corvair. The differential was also changed to permit suspension components to attach to the bottom of the differential, and to support the half shaft design in place of the older swing-axle design. Also, late models used larger GM intermediate platform (Chevelle, Tempest, etc.) brakes.

[troy.w]

Looks like the easiest way to do this would be to swap the entire rear end (left and right side suspension, and transmission) from a 65-69? What are the hiccups in doing that?

[bbodie52]

I think the difficulty is creating the correct anchor points on the EM body, since some Late Model suspension components anchor on the body, and not on the box section crossmember assembly seen in the EM swing axle design. The entire LM transaxle must be included in the conversion, since it is an integral part of the new design.

[joelsplace]

If you don't mind making sweeping changes to the body the LM suspension is far better. It will take a lot of fabrication work.
You can make big improvements to the stock setup by making solid engine, transmission and cross member mounts. Replace the control arm bushings with the Clark's nylon bushings and use some good shocks or even better fully adjustable coil overs. Removing weight from the rear will help a lot also.
It all depends on what you are trying to accomplish.
A nice side effect of all the solid bushings is much improved shifting also.
If you decide to go with the solid mounts make the transmission mounts adjustable so you can set the camber.
Edit: solid mounts are only an option for manual transmissions. They will break the case on Powerglides.

[bbodie52]

Toe-In Adjustment...the wheels are adjusted by adding or removing shims at the front edge of the transmission (with rear engine support loose), both wheels are adjusted at the same time. With the design of this suspension, it will be impossible to adjust one wheel at a time as shims must be added or taken away equally from each side. See Figure 3-35... CAMBER — The camber on rear wheels should be 1½° ± ½°. There is no provision for adjustment of this item and it is provided as a checking specification only.

[troy.w]

Thanks man. Appreciate it.

[colorsarge]

This modification is not for the faint of heart or the under skilled. Imo, unless this is to be an all out performance car, it is not worth the effort. My friend, Terry Stafford has been time trailing a 1964 Spyder in the Northeast for years with the original suspension in place with great results. Just say in'.

[Wagon Master]

My thoughts exactly. What issues are you having now with a properly setup 64 rear suspension?

[Allan Lacki]

As stated above, it would be especially difficult to install a '65-69 suspension in an '60-64 Corvair. You would need to be an expert fabricator, meaning superior welding skills and some engineering prowess to install trailing arm anchor points that are located correctly and strong enough to handle suspension loads.

If you have these skills, then go for it. But please beware - It is NOT a bolt-in installation.

Mike Levine, Terry Stafford, John Egerton and others have all been running swing axle Corvairs in high performance track days for years. Naturally, they're using racing tires, stiffer springs and other suspension modifications. But the point is that they're competing with other cars on the track with swing axle cars.

For street use, make sure you have good tires and shock absorbers and that your tire pressures are set correctly. You should be OK.

If those basic steps aren't enough for you, then relocate your spare tire to the trunk, replace your generator with an alternator and, if you really want to get radical, move the battery to the trunk too. Those things will help weight distribution a bit. But if your going to use your Corvair just for tooling around town, I wouldn't even go that far.

Whatever you do, do NOT install a rear anti-roll bar on the rear suspension of your swing axle Corvair. You want LESS roll resistance in the rear suspension. That's why Chevrolet installed the transverse leaf in the '64 - to promote roll in the rear while maintaining the overall spring rate. They compensated for that by adding a stiff anti-roll bar in the front suspension. You may have noticed that the racing guys DO install rear anti-roll bars in the rear, but those that do it are running very stiff springs that basically minimize suspension travel altogether on smooth track surfaces.

Another thing: Do NOT replace your engine mounts and suspension bushings with hard mounts or hard pieces unless you're building an outright single-purpose track car. You'll ruin the ride and have much more noise in the interior. There's nothing wrong with stock engine mounts and bushings so long as they are in good shape.

The '64 suspension with its transverse leaf spring is a big improvement as it is in comparison to the earlier years.

[joelsplace]

"Another thing: Do NOT replace your engine mounts and suspension bushings with hard mounts or hard pieces unless you're building an outright single-purpose track car. You'll ruin the ride and have much more noise in the interior."
If you are ever in the DFW area stop by and I'll give you a ride in 2 different early convertibles. One all stock and the other with solid engine, transmission and crossmember mounts. I'll bet you would be hard pressed to tell me which one had the solid mounts. If you drive them it is very noticable. Much better feel and precise shifting.

[61SuperMonza]

I wouldn't spend that kind of time or money on a swap like this. I will agree that it is cool but in the end the swing axle set up can be made to perform very well. A little negative camber in the rear(2-3 deg), wide base wheels with performance radial tires, and adjustable dampers. I would also lower the front end and install a 65-69 front bar. Then quick steering arms and a performance alignment. I would also remove weight from the rear as mentioned. A car like this would hold it's own with almost any LM. Just ask Mike Levine, his EM #362 will hang with any LM. Even with drum brakes.
Just my 2 cents
Norm

[nirvairna]

hello troy.w

I see in your intro post you are new to Corvairs, and you live in Albuquerque. There is a local Corvair club there, you can find info at:

http://www.unm.edu/~jimp/

Just my opinon: Your 64 can be made to handle well, I don't think changing to the late model suspension is worth it. Good shocks, tires and alignment are more important.

[Deadwolf]

I know, late to the party and I didn't even bring any more beer!

I'm thinking before I would go the LM rear suspension in a EM I would go with putting a C5 or C6 corvette rear suspension in.

In the following link they make a cradle that has all the attachment points for the upper and lower arms. Only problem is it is designed with a corvette rear end in mind and I think the minimum cradle width is 24", but if you talked with them about putting it in a corvair I doubt the corvair needs a 24" wide cradle and that would allow you to get the wheel base back to the 54.5" as original. I doubt if the cradle has to be more than 16" wide to fit in a corvair.
https://rick486.wixsite.com/dobbertinpe ... ter-basics

The big one I am wondering about is can I fit a LM front cross member into an EM without a bunch of fabrication?