Rear suspension upgrade- what should I buy

[PWICK911]

Looking to upgrade the rear suspension on my 911sc

Anti roll bar
Drop links
And lower it 20mm

Currently have green bilsteins which I will keep.

What do I need, and has anyone done something similar.

How much adjustment is there in the rear arms?

Thanks

[RL technical]

There is no point in just upgrading a rear sway bar? Why
The factory bar is fine for a street/ circuit car, torsion bars would be s good up grade, the sky is the limit.
What I suggest is to make sure all your bushes are in good condition, and go from there. Adding a bigger rear bar in a street car is a waste of time and money.

[Driven97]

A bigger rear sway on OE torsions is a recipe to tear out the mounts.

The factory design is pretty weak, and if you're using the sway for most of your roll control that puts a lot of load in those things.

I'd recommend bigger torsions first. Unfortunately, everything has to work as a system. They have to be somewhat matched to the shocks, and then you can't change the rear much before you have to start balancing out the rear changes with front changes.

So, before you do anything, you need to come up with an endgame plan of your true goals. Otherwise you are likely to end up doing things twice or worse.

[tobluforu]

Since you want to lower it and I assume you have the proper adjustable spring plates, dropping the rear is easy. But I would buy new torsion bars and bushings and go that route first which will allow you to index the bars and get the height you want. But if you drop the rear, most likely you will need to drop the front, which is a also easy. But since you now have bigger/better torsion bars in the rear, might as well get new bars for the front and bushings to along with it. Its a very slippery slope. Sway bars are last.

[PWICK911]

Originally Posted by tobluforu

Since you want to lower it and I assume you have the proper adjustable spring plates, dropping the rear is easy. But I would buy new torsion bars and bushings and go that route first which will allow you to index the bars and get the height you want. But if you drop the rear, most likely you will need to drop the front, which is a also easy. But since you now have bigger/better torsion bars in the rear, might as well get new bars for the front and bushings to along with it. Its a very slippery slope. Sway bars are last.

No,I don't have adjustable Spring plates.
Which are best and how much adjustment is there.

Also on the replacement of rear suspension components current items are past there best and need replacing, so instead of replacing I was going to take the opportunity to upgrade

[Driven97]

The 911sc has factory adjustable spring plates. Even if you didn't, all torsion bar 911s are height adjustable from the factory front and rear.

When you say "best" and "upgrade" what do you mean? What do you want? Everything is a tradeoff. Either you sacrifice performance, comfort, cost, noise, longevity, ease of use, or a dozen other things somewhere.

Are you building a race car where lap times are all that matter? A daily driver where OEM-like dependability is paramount? A Sunday drive car where looks and comfort are most important? A concours restoration? Somewhere in between?

If you can answer that, we can give you better direction on what may be the "best" for you.

[Joe Bob]

Sway Away adjustable spring plates and poly bushings.

[gtc]

The '86-'89 factory sway bars are a nice upgrade that give a modest increase in stiffness.

[hcoles]

^^^^ why?
Are you going to the track or AX?

[PWICK911]

Thanks for feedback.

I am looking for a Sunday car which I may also take on the track , so I guess a happy medium.
Ride is not a major thing as I'm running 17" wheels with low profile so the ride is harsher than factory.
I suppose I want to reduce the gap between the wheels and the arches- it's looks I'm interested in.
For the spring plates how mich adjustment is in them ?

[PWICK911]

[tobluforu]

Nice car. Spring plates-depends on where they are now based on how the bars were installed, so you may or may not have wiggle room. Its pretty easy to check, and yes that car needs to be dropped.

[Trackrash]

As others have stated, you need to treat the whole suspension as a unit, which includes also doing the front. If you only increase the size of the rear sway, you may find that the car will oversteer, with the rear coming around unexpectedly. Ask how I know.

HBTDT I would recommend first only lowering the car to your desired level, with no other mods. You may or may not be happy with the results, and you may end up with a better idea of what other mods you want to make, if any.

If you want to truly upgrade your suspension, replace all your bushings, front and rear, and go with larger torsions, front and rear. Leave the sways alone, unless you want a harsher ride AND you add an ADJUSABLE bar to balance things out.

I was under the impression that all SCs had adjustable rear spring plates. If your car doesn't, do yourself a favor and get a used set of stock adjustable spring plates.

[PWICK911]

Anyone know how much adjustment there are in the spring plates **mm

Cheers

[Dpmulvan]

You need to do some reading and research if you don't understand your suspension.

[mreid]

I don't think I would lower it without first understanding how worn your bushings, shocks and TBs are. You may have too much suspension travel and end up damaging your rear fenders or paint. If no work has been done in the past, figure bushings and shocks are worn and must be replaced.

[Yairi1]

I just had my 1974 Targa suspension redone, using the Elephant Racing tool. You can choose your degree of restoration and intended purpose and they will put together the suggested improvements. Elephant Racing | Suspension Builder | Porsche 911/912/930
Saved a lot of researching and drives like a dream now for my intended purposes, which is fair weather fun. I went with Sport Restoration 1. Figure about $3k in labor on that one.

[Driven97]

Originally Posted by PWICK911

Anyone know how much adjustment there are in the spring plates **mm

Cheers

Some? Here's a factory adjustable rear spring plate (what you should have on your car):



The rear springs on a 911 are torsion bars that sit laterally just forward of the rear wheel:



You can adjust ride height two ways on your car:

1) Pulling the torsion bar, and re-indexing. The ends are splined - that is, they look like a gear. If you pull them, rotate slightly, they'll push back in at the next tooth. That will change the ride height dependant on which torsion bars you have in there. This was the only way to adjust early 911s.

2) The factory adjustable spring plate in the top photo has a cam. This gives you a few degrees of "fine" adjustment. What you can do is largely dependant on where they are currently set. Supposedly, from the factory they were set at full low - you could only use them to raise the car. If you car has been apart before, someone may have set them in the middle position or otherwise and you may be able to lower without having to pull the torsion bars out and re-indexing.

As noted above, you shouldn't go all too much lower than stock on factory torsion bars. The OE ones are very soft, and there's a lot of suspension deflection. Going too low you run the risk of hitting your bumpstops, or your tires hitting the insides of your fenders. This can cause poor and unpredictable handling, and even damage.

There's a great tool online for using spring plate angle to calculate ride height HERE. "Euro" height here is about as low as you should go. With stiffer torsion bars you get less deflection and therefore can go slightly lower if desired.

The suspension is a system, it does all need to work together. You don't have to spend thousands to make a nice impact, though. Everything on the car is pretty simple. There's a LOT of grossly overpriced bits out there. Good luck.

[PWICK911]

Originally Posted by Driven97

Some? Here's a factory adjustable rear spring plate (what you should have on your car):



The rear springs on a 911 are torsion bars that sit laterally just forward of the rear wheel:



You can adjust ride height two ways on your car:

1) Pulling the torsion bar, and re-indexing. The ends are splined - that is, they look like a gear. If you pull them, rotate slightly, they'll push back in at the next tooth. That will change the ride height dependant on which torsion bars you have in there. This was the only way to adjust early 911s.

2) The factory adjustable spring plate in the top photo has a cam. This gives you a few degrees of "fine" adjustment. What you can do is largely dependant on where they are currently set. Supposedly, from the factory they were set at full low - you could only use them to raise the car. If you car has been apart before, someone may have set them in the middle position or otherwise and you may be able to lower without having to pull the torsion bars out and re-indexing.

As noted above, you shouldn't go all too much lower than stock on factory torsion bars. The OE ones are very soft, and there's a lot of suspension deflection. Going too low you run the risk of hitting your bumpstops, or your tires hitting the insides of your fenders. This can cause poor and unpredictable handling, and even damage.

There's a great tool online for using spring plate angle to calculate ride height HERE. "Euro" height here is about as low as you should go. With stiffer torsion bars you get less deflection and therefore can go slightly lower if desired.

The suspension is a system, it does all need to work together. You don't have to spend thousands to make a nice impact, though. Everything on the car is pretty simple. There's a LOT of grossly overpriced bits out there. Good luck.

Thanks for the info.
Answered my questions.
Getting a specialist to look at a what I can do for my budget over the next few months once it's passed its MOT in the uk.
Will keep everyone posted

[rusnak]

A nice Sunday car and one that you can take to the track are total opposite extremes, and really there is no happy medium. I'd say you realistically need to weigh one over the other and choose where you want to be in that spectrum.