SWB sway bar question

[ttw18]

I am looking to do a front end swap on my '67. The few that I have looked at do not use the through-the-body sway bar. My questions are:

1. Is one type of sway bar more desireable?
2. How do you locate and install the bushings that mount to the body? Just drill holes and bolt in, or is there more to it?

[304065]

Through body has better mechanical advantage than the old carrera style

Look at the installation instructions for Smart Racing's bars, these are available as a PDF on their web site. Explains in detail how to do it-- this is what I would use if you aren't doing concours/OE "Pencil" 13mm bar

[JCF]

I kept the stock 13's pencils : )

[TRE Cup]

You car came with the sway bar mountings already in place up front. If you install one in the front. you need to do the same out back. Otherwise it won't be balanced. Factors that help you decide what size bars would be best; how wide your wheels and tires are, how aggressive you drive in the twisties, and are there other performance upgrades done to shocks / torsions

[ttw18]

So my car has NON-through the body mountings already? Would this different bar change the spring rate enough to require the use of a rear bar. I do not want to install a rear bar. What year did the 911 stop using a through the body sway bar? I may just search for the correct arm that will allow me to use my current sway bar.

[TRE Cup]

The factory produced the 912 with a front bar only. All 911's that had the sway bar option , have them installed front and rear. DO NOT install a front bar only on your 911 !

[JCF]

Originally Posted by TRE Cup

The factory produced the 912 with a front bar only. All 911's that had the sway bar option , have them installed front and rear. DO NOT install a front bar only on your 911 !

The earliest 911's only had the front 13mm bar.
The rear bar was introduced (to the prod models) with the '67 S

I have never had any issues with my car on the street or at the track with the original set up.
As a matter of fact , it is very nice - though I am not out for any track records, it is mostly used for fun back road driving.

[TRE Cup]

thank you for correcting me! there is always room to learn something

db

[JCF]

db - Believe me, I defer to you on all things Porsche - I only know the '67 car from personal experience.

[Grady Clay]

db,

I agree. I learn something every day. Email me.

While the technical sway bars (F & R) are easily available, SWB (and early LWB) mounting are not obvious.

In the front the issue is the ‘through chassis’ mounting. All the chassis have the provision for the through chassis mounting, even when not Factory mounted. The Factory retro-fit mounting has a 3-stud plate to install inside the inner fender. In practice, the best fit is using an additional outer stamped piece on the inside using three nuts & bolts. Of course you can weld-tack the bolts to the plate. Another important issue is to axially locate the sway bar.

The front A-arm attachment can use improvement. At least one vertical link needs to be adjustable to prevent any pre-load. The ’74 and later need a conversion.


In the rear there are several attachment methods to the trailing arms. SWB and LWB are different. In either case I recommend an improvement over the Factory original attachment. I prefer a welded tube through the trailing arm with a through-bolt and a spherical bearing.

Another important issue in the rear is the attachment of the sway bar to the chassis. The original system isn’t adequate. There are several aftermarket brackets that are improvements. Extending the connection along the inside frame to the torsion bar tube is even better.

It is very desirable to not let the rear sway bar & linkage to extend below the car.

Both F & R sway bars must be very free to move and not have a pre-load on the suspension.


There has been a lot of discussion on these issues. Searching all the forums will provide more info.

Best,
Grady

[ttw18]

Grady, you're thinking of a sway bar swap in the other direction. My car currently has the through the body sway bar. I will not make the swap if:
1. Through the body is better
2. Mounting the other type involves fabbing new mounts for underneath the body
3. all of the above

Thanks