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Re: Corvair EMPI Camber Compensator
Posted by: 7004doorL ()
Date: October 08, 2019 05:25PM

If I am not mistaken a 60 - 63 Corvair car has 37% of its weight
on the front and 63% of its weight on the rear.
Easy to remember same as Eutectic Tin/Lead Solder.

Using a mid engine design even in a custom frame would surely
yield a different weight distribution.



Is the wheelbase on the custom frame going to be 108 inches like an EM?

Mike
1960 4 Door
80 HP PG

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 08, 2019 05:37PM

That is a funny picture since it isn't illustrating what the "camber compensator" is supposed to do. It can't and isn't supposed to do anything with the car jacked straight up like it is in the picture.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 08, 2019 05:39PM

Thanks Mike

'Eutectic Tin/Lead Solder'

That is a sore point with me.Have stack of boards waiting for me while I learn how

to solder.

'yield a different weight distribution'

Yeppers! That is why first mid engined cars showed up at Indy around '63 and it

has been that way ever since.

'going to be 108 inches like an EM?'

Have yet to get to that level of detail yet.

If you are interested in doing that yourself it is quite doable.

You just supply the motivation! Everything necessary is available.

THE CALIFORNIAN

A man of independent thoughts.

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 08, 2019 05:41PM

Found out in Wikipedia what 'positive camber' is.

Here is picture with negative camber.

Negative is how you set up your Corvair.

Probably not to the degree of this car.

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Re: Corvair EMPI Camber Compensator
Posted by: Wagon Master ()
Date: October 08, 2019 05:57PM

Sale Pending!

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 08, 2019 06:10PM

'jacked straight up like it is'

It was a handy picture to show 'tucked in' wheels.

Let's look at a rear wheel drive front engine.

Would anybody put the engine AHEAD of the front axle.I don't think so!

If you did the rear end would break loose fairly easily.

So.Corvair has and BEHIND the axle like our little example.

Corvair you have the lightly loaded front axle dealing with weight swinging

around there off of the rear axle.

Add the swing axles and you have your work cut out for you getting it to

handle.

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 08, 2019 06:59PM

A ton maybe even most front wheel drive vehicles have the engine ahead of the front axle. I can't think of any that don't.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Corvair EMPI Camber Compensator
Posted by: 7004doorL ()
Date: October 08, 2019 07:04PM

A good starting point for Soldering Eutectic Solder is 500 Degrees F.
if using a Solder Pot. Or Wave Solder Machine.

I used to Clean and Maintain these.

Hand Soldering with a Soldering Iron is an art form. I have no Certification.

Use Acid Free Flux for any stranded wire Assembly.

My previous 1962 Monza sat at rest with a little Negative Camber at the rear suspension.

My 1960 rear suspension looks to me to be Vertical or Zero Camber at Rest.
Same today as when I brought it home on a trailer in 1987.

Tire wear tells a Story.

Been working on my 1969 and driving it when drive able since 1988.

Careful of those Negative Camber Pictures; some were taken with rear shocks removed. To shock people. Rear Shocks on Corvair are the top out limiters.

Some folks did use straps. To Limit Negative Caster.

If I remember correctly Corvair Swing Arm rear suspension was 2 1/2 Degrees
Positive and Negative Camber. Straps limit the Negative Camber.

But once airborne all bets are off.


Mike
1960 4 Door
80 HP PG
Salvaged Title
Registered in CA since 1988.

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Re: Corvair EMPI Camber Compensator
Posted by: MattNall ()
Date: October 08, 2019 07:36PM

Mike... you've got a few errors..

EM REAR

1 There are rubber snubs to cushion the upper limit as well.

2 Factory spec allows +/_ 0.5 degree CAMBER.

3 Straps are used to limit POSITIVE CAMBER [wheel Downward travel/Pos. camber ].

4 No "Castor" in the rear... front only

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 08, 2019 07:49PM

'front wheel drive vehicles have the engine ahead of the front axle'

Those are transverse engines.That means 'sideways'.

I was talking about longitudinal.That means 'straight'.

Like Falcon, Dart,Valiant and Chevy II.

Would you want one of those with engine totally in front of the front wheels?

'Hand Soldering with a Soldering Iron is an art form'

Want to get it right before working on hard to find old boards.

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Re: Corvair EMPI Camber Compensator
Posted by: 7004doorL ()
Date: October 08, 2019 07:52PM

I tried and I failed.

Except I did not reference bottoming out in the suspension.
Only topping out when airborne.

Apologies,

Mike

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Re: Corvair EMPI Camber Compensator
Posted by: MattNall ()
Date: October 08, 2019 08:11PM

Right... what the Snubber on the LCA is for..

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 08, 2019 09:39PM

There have been FWD longitudinal mount engines that were in front of the axle but I see what you are getting at with the cars mentioned.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Corvair EMPI Camber Compensator
Posted by: ensys ()
Date: October 08, 2019 10:00PM

Like Don Quixote, I just can't resist windmills.

Mr.M: A truly heroic (and predictably futile) effort. Kudos.

To those who sensed Truth in his piece but were still scratching their heads, I offer this link [old.motoiq.com] as a possible means of some clarity.If nothing else, it illustrates some of the key terminology.

In an effort to toss a helpfully deflecting pebble in the wayward path of the rolling boulder that is this discussion, I would offer this: Beware of simple "solutions".

Big negative camber at the rear, in and of itself, is a blind alley. While it may (with emphasis) help in some low speed situations, make no mistake; tuck lurks, just like before. In the meantime, it eats tires like peanuts owing to the greatly reduced contact patch (which no wide tire can help) and increased toe-in, while making road speed in a cross wind very exciting indeed. Then there is the reduced ride height problem; it lowers the center of gravity and roll center, but does not change the roll couple.

On another note, as the roll center of a swing axle is quite high (and cannot be modified to reduce the roll couple )and the center of gravity of the rear engine is not, the trick is to reduce the rear roll stiffness with softer springs, thus reducing the tendency to lift with weight transfer. However, this reduces the static load capacity, allowing the rear to drop, causing increased negative camber in the process. It is the role of the "camber compensator" to restore the normal static ride height, thus compensating for the increased camber (which should be no greater than 1/2 deg. in the negative).

This approach is complemented by a stiffened front suspension (thus the '64's anti-roll bar) to do all the work of roll stiffness.

The problem is that the EMPI configuration is not a true camber compensator. To understand why, one should look to Porsche's solution for the S90 and later 356s. Their solution acts only in one direction (upward at the center) and is not affixed to the chassis in the center, so that it makes absolutely no contribution to roll stiffness in a cornering situation.

However, the EMPI solution is not without the potential for merit. If configured correctly with a frictionless center pivot (think of a longitudinal hinge) and adjustable ends (to set a small static pre-load), it can act as what may be accurately described as a "Virtual Z Bar", which can use the drop force of the outside wheel to force the inside wheel up when cornering.

This might seem familiar ground to some, as I have preached this sermon before. If experience is any guide, I've wasted my time again.

$.02 from the peanut gallery and pass the beer....

Keep 'em flying...

S.J.Szabo

From America's
Automobile Heartland

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 08, 2019 10:56PM

Thanks Joel

The front engine example was to make the Corvair case clearer.

Corvair heavy rear and light front.

Szabo

Copied guts of your post into Notepad file.

Lots to think about there.

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 09, 2019 09:41AM

S.J. good summary of the "camber compensator".

"The problem is that the EMPI configuration is not a true camber compensator."
I realize the center bracket is not "frictionless" but I can't see how it would contribute to the roll stiffness in any significant way unless it is a lot different than the Corvair one. (I haven't seen one in person).
I just figured the bracket was mainly to keep the leaf from making noise and so they didn't have to rely on the outer mounts to keep is positioned.
I've seen pictures of the '64 leaf installed on cars with earlier differentials and no mount at all.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 09, 2019 10:36AM

Applying common sense to this.

Goal is to pull INSIDE Wheel and axle UP.

I will leave it there.

Best way to clear muddy water is not to stir it.

THE CALIFORNIAN

A man of independent thoughts.

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 09, 2019 10:43AM

The inside wheel isn't a problem.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: October 09, 2019 11:17AM

'The inside wheel isn't a problem'

Well.There you go.

If having a wheel ride on the outer edge is not a problem then there is not a

handling problem.

The outside wheel is 'planted' by a split axle.

The inside wheel gets canted.

Canted with the outer edge of tire only making contact.

Each turn is like part of an oval race track.

The part inside the oval is the inside.

The part outside of the oval is the inside.

'#10 drops to the inside to pass!'

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Re: Corvair EMPI Camber Compensator
Posted by: joelsplace ()
Date: October 09, 2019 11:26AM

I should have said isn't the problem.
The problem is the swing axle acting like a big lever. Load on the outside wheel tends to do the opposite of what you would think and extend the suspension and "jack" the rear of the car. When the wheel extends then it runs on the outside edge of the tire which is also bad. Some say it can be bad enough to dig the wheel into the pavement and roll the car but I haven't been able to reproduce that.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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