930 suspension in pacific nw?

[zakthor]

My '79 930 needs suspension work. Each time I've done suspension work before its been a total crap shoot and I'm always surprised when I get the car back.

Lots of experienced people full of awesome advice, but for once I'd like to know what I'm getting before I pay the moneys.

My car is a daily driver and my street has speed bumps, so not looking for a full crazy track thing. I believe I'll prefer something sportier than stock, but that might just mean a slight lowering (euro height?)

Does anyone in seattle area have a 930 suspension setup nice lively smooth? Something youre really keen on?

Please email me if you have a good handling 930 in the seattle area that you'll let me drive (and copy). In return I can let you drive my 930 that auto steers on throttle lift.

[spuggy]

You probably should start with a good alignment, or at least getting it checked and make a plan from there. Tru-Line, either Bellevue or Seattle.

[9dreizig]

Give Craig a call

[Craig 930 RS]

Tru-line. Remember it is hard to make these cars plush riders, and handling almost always involves a compromise. That would be comfort.

I'd start with a modest lowering which may involve reindexing of the torsion bars and an alignment -

[zakthor]

Yes, definately it will go to truline in bellevue. Always good but I never know what I'll end up with.

I can take the car in, have them do their thing and then realize the torsion bars are too soft. Iterating on my own car is an expensive way to build a vocabulary.

For the sc the stock euro height was nice but a little softer than I like. The 930 is different but I don't know what a good one is supposed to feel like.

Question: Is it better to send the shocks in to bilstein? Or just go with new ones? Price is comparable? Hd front and sport in rear?

[JFairman]

Try to decide on a ride hight befroe doing a 4 wheel alignment because if you decide to reindex the rear torsion bars to lower it, the alighnment you paid for is thrown in the trash.

You have to completely remove the rear springplates to reindex the torsion bars.
That means unbolting them from the trailing arms and that completely removes the rear wheel alignment and it will have to be done again.

It's aligning the rear wheels that is 100% hit and miss until it comes out where you want it with the car back on the ground and the tires and suspension all settled and driven at least 10-20 feet to get the tire camber settled out.

[pdx930]

I had Rothsport do mine with the understanding that it was primarily a street car. They did the following:

Tbars: 22 fr, 29 rr
Shocks: Their custom valved bilsteins fr, Von's in the back
ERP polybronze bushings front and rear
Spindles raised 19 mm
Tie rod end bumpsteer kit.

I'm quite happy with the setup. It made the car MUCH more secure feeling, especially in the rear, with relatively little ride penalty. If you are worried about road grain noise in the car, I would stick with fresh rubber bushings. It's not intolerable by any stretch of the imagination, but a definite increase in noise over stock.

[zakthor]

pdx: Raised spindles? How low is your car? How far below us stock before one should raise the spindles?

Do you have a photo?

[pdx930]

I'll take some measurements tonight. I asked him to put it where he thought it would work best. I have no issues with the local speed bumps at this height

The only pictures I have handy are a crappy iPhone snapshots. Here's one from a spontaneous drive to the coast.





Here's an even crappier one from when one of our friends' 16 year old son's wanted a picture for his friends, but I think you can see the ride height pretty well.

[jeff91C2T]

If you have the time you might want to consider the Oct 16th PCA autox out at Bremerton. There will be a handful of 911/930 based owners to give you plenty of input...and probably a few rides as well. Details below;

PNWR

Originally Posted by zakthor

My '79 930 needs suspension work. Each time I've done suspension work before its been a total crap shoot and I'm always surprised when I get the car back.

Lots of experienced people full of awesome advice, but for once I'd like to know what I'm getting before I pay the moneys.

My car is a daily driver and my street has speed bumps, so not looking for a full crazy track thing. I believe I'll prefer something sportier than stock, but that might just mean a slight lowering (euro height?)

Does anyone in seattle area have a 930 suspension setup nice lively smooth? Something youre really keen on?

Please email me if you have a good handling 930 in the seattle area that you'll let me drive (and copy). In return I can let you drive my 930 that auto steers on throttle lift.

[bcoats]

for what it's worth, I went with Bilstein sports all around, 22/28 torsion bars, euro ride height and front strut brace, suspension had a nice tight sport feel but not too harsh at all, Truline in Seattle set it up as well and set up the camber as well for track days

[zakthor]

Pdx930: that doesn't look so low. My sc was originally lower than that and it didn't have lowered spindles. I wonder what drives the decision to lower the spindles, I thought it was to keep the suspension into its sweet spot. Is there a visible criteria like "front control arms parallel to ground"?

bcoats: I put sports on the sc but with stock torsion bars. Front was too stiff, not for comfort but felt like car was bouncing off the shock and didn't flow. Your car sounds close to what I was considering though.

[911st]

I would inspect the car first for bushing ware front and rear. With the car on its wheels, is the rear spring plate still centered. Same with the front but look mostly at the rear a arm.

Most likely it is time for bushings if this has not been done. If that is the case you are in for a major investment and you should decided if you want any upgrades like stiffer springs.

Rasing the front spindle on a 930 is a handling upgrade. It mostly improves the front camber curve and is a good compliment to the special 930's rear set up. It also brings back some of the front suspension travel lost on a lowered car. You can also have the front spindle de-cambered if you are going to track your car as we are camber chalanged otherwize for the most part. However, with this you will also need a bump steer kit so this is about an $800 addational investment.

Tires, shocks, and bushings are going to be the areas you want to look at most for ride quality.

Tires are the softest part of the effective spring rate. However most the modern sports car tires have much stiffer side wall's. This is the easiest place to look for comfort. It is also the best place to look for performance improvement.

Shocks come in touring, HD, and Sport. HD's are still more of a sport shock and I believe have a pretty stiff rebound at least up front. Custom valveing is probably your best improvement to concider to effect your ride quality.

Bushings are a challenge. Most that go to the hard ER race style bushings say it improves ride quality.

The stock bushings are rubber and require some thought to replace. The best way to renew them is to buy new factory front A arms and rear spring plates with the rubber installed by the factory. However this is very pricey. Elephant Racing makes very good replacement rubber bushing. It is only my opinion but I believe there rear replacement's really need to be supper glued to the spring plates. Otherwise they will creak and ware out early.

[zakthor]

Thanks for the description. Man this board is so great!

How would you describe what "mismatched camber curve" feels like?

I'm approaching this assuming the car needs some bushings and new/rebuilt shocks, then ride height and alignment.

I've driven four 930s, each has had stock (and old) suspension, and on every one I've felt a mismatch in the way the front and back settle into a corner, like they are disagreeing about the toe until the car is settled? More than just the extra weight out back. Also most have been setup too high, feel like I'm driving a truck.

Likely the suspensions have all been shot. I can tell the cars aren't supposed to feel like this, but I don't have the vocabulary to say whats happening.

My car right now feels particularly nasty. Front end rattles, rear wheels steer out in peculiar ways if I do anything but keep my foot planted, currently feels like the front and rear toe are arguing with each other and the changes are surprising and abrupt.

Repaired similar global symptoms on my sc and it wasn't cheap. Core issues were fixed yet I didn't get exactly what I wanted so this time I'd like to be more involved which means being more informed.

Seems like lots of the expensive parts are made with adjustability in mind, which I don't think I'll be needing once the car is setup. Some other pelican threads have hinted at how the parts save money since setup is so much faster.

Best case, I decide exactly what I want (stock?), then pull the trigger once. If do anything more than stock I'd like to have an example then I can just point and grunt: "me like that one!"

If lowered spindle and "de-camber" will make me happy then I should do it, but first I want to feel what I'm getting.

This sort of feels like shopping for my first motorbike where I was expected to buy the bike before riding it.

[911st]

I do not know if I would say the curves are miss matched . More like the front's camber curve is not as aggressive or beneficial as the rear.

The goal is the have the tires at there best angle in a corner.

This can be had by dialing in a lot of static neg camber or having the suspension designed so neg camber is gained with suspension compression in a corner.

I guess you could say the camber curve lets you minimize ware on the inside of you tires on the street and the outside of the tires on the track. If you do not have a good camber curve you have to choose between handling and tire ware.

On the back of a 930 you can set your neg camber at a lower level than on a 911 and when the car corners the rear tires lean in more gaining neg camber so they are at a better angle to the track.

On a stock front end if it is lowered it puts it in a pretty flat part of the camber curve and there is little additional neg camber gained with compression/ cornering.

I think about the most static neg camber you will get in the front is about -1.25 deg. Even with a sport springs one can often use up to -3 deg up front on the track.

One way to get more static neg camber is to go to something like the Smart Racing Products Camber King strut tops and bar that has more range of adjustment.

Or, you can have the front struts raised and the axle decambered at the same time. You get more static neg camber from the decambering and you move to a part of the camber curve where you get more neg camber from cornering.

Stiffer suspension and stiffer sidewall tires also help as they limits the cars lean which is a factor in how much camber the tires need to be at the ideal in a corner. Stiffer bushings also reduce camber loss at the bushings though this is not a large amount.

Unless you are just killing the outside of your front tires on the track or are supper competitive most just dial in what neg camber they can get up front and live with there limitations.

Stock 911/930's really softly sprung. In the right hands with good tires they can be fast on the track. However they want to pitch and roll quite a bit and you have to work them into a set. Fine for DE's but would not be much fun in fender to fender racing. If going to the track stiffer springs (not necessarly sway bars) make the car much more predictable and safe.

[zakthor]

Conclusion:

Asked around including at local autocross and track and took car to highly recommended Seattle area shop (Fordahl).

He told me what to get and after researching I ended up doing exactly what he recommended:

22/30 torsion bars (sanders hollow)
shocks are hd front, sport in rear
polybronze for front control arm, rear torsion bar.
camberplate monoball for top of front shock
sway bars from mid year carrera (22front, 21 rear)
corner balance and "strong street" alignment; its lowered to just about 24".

Sway bars are sadly still in the mail, they will be installed later (2 weeks or so).

Picked up car today... whoa!

- Ride is smooth and wonderful and quiet.
- Plenty of travel for potholes and irregular surfaces.
- Steering is super light, steer with 1 finger.
- Car tracks very straight but turns in beautifully, very smooth and planted through corners.
- Squat is greatly reduced, no longer an issue for me.
- Wide track isn't noticable any more, car feels very natural.

I can echo what others have said:
- monoballs and polybronze bushings definately don't hurt the ride
- 22/30 doesn't feel too stiff to me

Cant wait to go driving tomorrow.

[mark houghton]

Originally Posted by zakthor

22/30 torsion bars (sanders hollow)
shocks are hd front, sport in rear
polybronze for front control arm, rear torsion bar.
camberplate monoball for top of front shock
sway bars from mid year carrera (22front, 21 rear)
corner balance and "strong street" alignment; its lowered to just about 24".
.

Sounds like you got great results with this setup...but what exactly is that ^^^

[zakthor]

"Strong street" is what he wrote on the order sheet.

While I have the precise settings I don't feel like they are mine to share.

I'd feel differently if I had a part in choosing them.

[mark houghton]

Originally Posted by zakthor

"Strong street" is what he wrote on the order sheet.

While I have the precise settings I don't feel like they are mine to share.

I'd feel differently if I had a part in choosing them.

Fair enough. Trade secrets are - after all - secret. Just looking for the optimal setup for Pacific NW driven cars. They're different than the rest of the country