Suspension/Torsion Bar Advice

[cajun]

I did a search but I could not find anything to help me make a more informed decision...

I just got my '81 911 back on the road and now its time for me to turn my attention to the suspension. Other than a Rennline strut bar, everything is stock, and for the most part feels like its 31 years old.

The car will be used on the street 75% of the time, and the rest of the time I will use it on back roads, AutoX, and DE. The car will not be a all out track car, I am building a Spec Boxster to fit that slot.

I am looking for a relatively aggressive street setup that is also capable on back roads or track settings.

Here's the question:

Given the above description, what size torsion bars should I go with? How about sway bars? I have looked around and these parts seem reasonably priced, but I don't want to spend a ton of time guessing.

Thanks in advance for any input!

[Dublinoh]

Have you checked out elephant racing site?

[Flieger]

Your best bet is to drive friends' cars which have similar weight and performance mods (tires and weight reduction most critically) to what you will be doing. This is a highly subjective area. I would be fine with race suspension on the street since the roads are good around here and I am young. My Dad, on the other hand, not so much.

YMMV

21/27 might be a good place to start.

[Steve@Rennsport]

Cajun,

There are a lot of other factors that influence the choice for torsion bars, matching shocks, bushings, etc.

Local road conditions, tires, swaybars, and how you drive also play a big role in the total package configuration so that everything works together properly.

[RWebb]

ask yourself: what did P AG do with the RS touring models? (which had more compliance than most cars today anyway b/c of the taller tires used)

[toddu]

I have the same car. I went with polybronze bushings, 22/29 TB's, adjustable sways, and custom valving via Steve @ Rennsport. Also properly aligned and corner balanced.

Ride is night and day from before (all stock, but Bilstein HD's). It's stiff, yes, but it isn't bone jarring. I think it's much more confidence inspiring than the stock setup while still being "comfortable" enough for a weekend car. On a rough road, it is noticable though (but so was stock, I think due to the HD's).

Todd

[avr924]

Polybronze bushings, 21/27mm t bars (not sway away, mine broke), late model 911 sway bars (I think 86-89 but 86 is ideal with 915 trans, also a direct bolt in, no welding or cutting required), send shocks and struts to Bilstein to revalve to sport spec, turbo tie rods, new rubber OEM sway bar bushings. Great set up, all bolts right in, great on the track, great on the street, of course align too.

[RSTarga]

If your car is 75% street. I second rwebbs answer. Basically renew your a arm and rear bushings with elephant rubber bushings for low maintenance and a great street ride. Stay with your front tbars 26 on the rear. As noted above elephant has a great chart which is pretty simple and takes most of the guesswork out. I wouldn't go any stiffer than 21/29 for the street.
Do not use polyurethane bushings they are hard and noisy. The Polybronze are good but they need greasing every 3,000 mi. That is why IMHO for the street elephant rubber is the best. Make sure and change them all inner and outer rear trailing arm and the front a arm and upper shock mounts. After 31 years they are hard as rock or disintegrating. Another thing would be new sport rubber motor and transmission mounts.

[Flieger]

Rebel Racing bushings do not require maintainance and greatly reduce the deflection that one would see with rubber bushings or the (stiffer than rubber) polyurethane bushings on the polybronze. They are also light and quiet.

[Lukesportsman]

Its a my 72' but just a reference point. Purchased the car at near stock height with Koni's and it drove pretty well. I knew I wanted to go harder core so taking advice on many on the board I upgraded to 22/28's. Again this is a lightened 72 with Mag engine and FG ends. It road very controlled and quite comfortably on the road, though small tired. I love my 22/28's and it is perfect for my use, but noticeably stiffer than the 21/26's (oops not stock) that I took out.

Three points:
1. These are old performance cars that you can't assume are stock
2. Small changes can be noticeable at the tipping point
3. As said above and from my example: the OEM turbo setup is nice for a regular 911 and in a lighter model still offers a performance advantage. (The 930 didn't s*ck)

[Lukesportsman]

duplicate

[RWebb]

some salient points:

1. he has another car for DEs

2. he will be driving this car on Louisiana roads -- maybe even New Orleans streets

[will hung]

You'd be surprised how much refreshing the wear items on a suspension makes an improvement to the ride and handling of the car. For those that report that they upgraded their torsion bars along with everything else and were surprised how it didn't degrade their suspension. I totally believe this, but with stock torsion bar and new bushings, these cars ride very smoothly. With worn out bushings, the car will feel like it has a welded suspension. New rubber bushings throughout from Elephant racing, Bilstein sports all around, and 26mm rear torsion bars are a very nice compromise for primarily a street car.