Elepahnt Racing bushes or 935 type rear swing blades

[1meansc]

Hi guys,
I will be upgrading my suspension at the end of the year, and would like comment on the following.
The car is a track car and a daily driver.
I would like to know what would be the best rear suspension setup. I will be going with coil overs and rear mono-balls.
Would the 935 style rear swing blade be better than the Elephant racing polly bronze bushings, even with the torsion bars removed.
What change is there in the rear suspension geometry when the 935 rod end is raised by 1inch, as what seems to be done?

What wheel alignment changes should be done if any after the changes. I want spring rates equivalent to 29 or 30mm torsion bars.

Thanks for your help.

[Tyson Schmidt]

You can't use the upper position on the 935 spring plates unless you install camber boxes for the inner pick-up points.

Otherwise, you'd have about 10 degrees of negative camber in the back.

If you do run the inner camber boxes, and position the 935 spring plate in the upper position, you will raise the roll center height in the rear, which reduces the need for stiffer springs and swaybars. It's like built-in anti-roll.

It will also build in some anti-squat, which will improve traction in the rear under hard acceleration.


Now, which is better? For a daily driver, I'd stick with a pair of pre-'77 non-adjustable spring plates with Elephant Racing Poly-bronze bushings. (You don't need adjustable spring plates since the height will now be adjusted with the coil-overs)

The 935 set-up is better if you are going with the camber boxes, and want the ultimate track set-up though.

[1meansc]

Thanks Tyson,
Who makes the inner camber boxes, and at what price.
Would there be any loss in driveability with the 935 setup with camber boxes, compared to the polly bushes.
Thanks again

[Porschekid962]

Smart Racing Products sells them along with a list of other vendors. Last I looked they were in the 600 area I think. Then you get to cut and weld. Driveability is a personal opinion, Jack Olsen's BBII has the inner camber boxes and I am pretty sure he drives her around on the street quite often.

[Brother]

This is greek to me. What are some good suspension books, Tyson?

Or is this all experience?

[drsimonwong]

Have you considered Wevo's spring plate?

Simon

[Dixie]

Are Wevo spring plates available yet?

They look like THE ticket. All new arms, completely plated, easy height adjustment, and SEALED BEARINGS.

Now, if someone would make sealed bearings/bushings for the front...

[Tyson Schmidt]

Smart Racing sells the camber boxes. You have to cut out a portion of the rear seat bottoms to clear, and make boxes with access panels for adjustment. That is usually not conducive to keeping a car streetable. But Jack's car is very streetable, despite being on the far end of tolerable as far as ride quality.


As far as books, I'll have to go home and find the name of the book that I like the most. Some are more detailed than others. I've learned much through trial and error, critical thinking, reading all I can, and talking to intelligent people.

Most that I know of, even the Gurus, tend to focus on key aspects, and leave out some of the details. I've seen cars modified by other shops that were not done comprehensively with the driver and application in mind. Sometimes they just get caught up in doing the most extreme mods to all the key areas, and end up with a car that is not very driveable. That's kind of why I'm steering you away from the full 935 rear suspension. Unless you are going all out, it's a lot of work and money for something you won't even notice with your application.

[drsimonwong]

Wevo spring plates about $900. Contact Hayden.

Simon