Why does my car handle funny?

[HarryD]

Originally posted by pwd72s
OMG...some scary pics here. Guys, all I can say is to REALLY think about suspension. I recently had mine gone thru by Jeff Gamroth of ROTHSPORT. I wanted to do some "racy" things he advised against, knowing me and my car. I argued back to the racy side. Then it dawned on me...this guy is THE winning ALMS Porsche's crew chief. I finally said: "Jeff, make it a car that you would enjoy driving on the street & backroads....He did just that...in spades. To repeat...REALLY think about suspension. Then? Listen to the people you trust. The check writing may hurt, but the final results could be worth it.

After consulting with Steve Weiner and Jeff Gamroth on parts. I went ahead and replaced my kinda dead Springplate Bushes (much better shape than those pictures above) and put new Bilsteins in. I inspected my front bushes and they got a "Thumbs up", so I left them alone.

Smokey just returned from the "Gamroth Spa". I told him my plans, asked a few questions about what he intended and why, and left. Two days later, it was like a new car.

Interesting, he set up my car differenlty from yours for several reasons (more AutoX for me, wider tires etc).

Then again, just what DOES he know? .

[Neilk]

My car handled rather poorly too, so one day while working on the rear brakes (read projectitis), I replaced the rear bushings with factory trailing arm bushings and Neatrix spring plate bushings. OH my GOD, what a difference that made.

[KobaltBlau]

Originally posted by TRE Cup
We really like to install The Elephant Polybronze for any type of performance oriented 911 (and 914) owner.

What do you guys do with inner banana bushings and strut tops in these cars? I realize monoballs are available but do you always do them?

Thanks In Advance.

[patkeefe]

Neatrix guys:
What kind of grease do you recommend? I'm putting my rear bars back together this weekend. I don't want it squeaky.
Thanks!
Pat

[patkeefe]

The old bushings, by the way. They rusted/decomposed at the torsion bar cover. I'm putting the old covers back on, but I'll reolace them as soon as I find new ones.

[HarryD]

Originally posted by patkeefe
The old bushings, by the way. They rusted/decomposed at the torsion bar cover. I'm putting the old covers back on, but I'll reolace them as soon as I find new ones.

I have my old set for sale. They are sound but need to be media blasted and coated. They are in the sale ads here.

[speeder]

So Paul, I'll bet your car is sweet now that Gamroth put his hands on it! What parts did you go with?

[Wil Ferch]

TRE CUP:
What's the latest word on rear Neatrix?.....lube the ID for the slip=over fit onto the spring arm...or "glue" the ID? There was a valid debate as to the pro-con of each choice.

Also...if you lube the ID, what about the inboard position of the rear bushings.....can't get at them to lube again "in-place". Problem?

Wil

[TRE Cup]

We use the silicone grease inner and outer. There has been no problems so far from using this method. Understood that the originals were vulcanized on the inside- there fore stationary. But we feel that the silicone grease is adequate. Of course if you use some strong detergents or steam clean your chassis sometime in the future, then yes you will end up having to lube them again

[98GTW]

Originally posted by Chuck Moreland
Wow

Charlie, a quick visual check can be made. Look at the tube-portion of the spring plate where it exits the spring plate cover. It should be perfectly centered in the hole.

If it is off-center, your bushings are toasted. In extreme cases, the tube will actually be in physical contact with the spring plate cover.

What Dave has pictured is beyond extreme!

Chuck (or anybody),
Have you got a photo of the assembly in place showing the off-center tube you describe?

Thanks,
Dave

[patkeefe]

I've superglued the Neatrix bushings to the spring plate, but didn't install the spring plates yet. I have been trying to research this a bit lately, and have been contemplating the forces in action on the spring plates and bushings. I think the spring plate bushings are only part of the rear suspension equation, the other part being the trailing arm bushings.

My conclusion is that the lateral forces in a turn need to be more or less rigidly restrained...if the wheels are firmly in contact with the ground, what restrains the body from moving in the "straight line path " it was on? The more lateral instability in the bushings, the more roll induced into the body. Thus, the forces on the TB cover bolts become quite substantial. The front suspension is restrained by the design of the control arms (TB's parallel to the direction of travel).

That being said, lubrication of the bushings will certainly help out in the purely rotational motion of the spring plate, but will tend to allow lateral motion more freely. I also feel the engineers at Porsche used the bonded rubber for its damping characteristics and the ability to offer thrust resistance.

This is just an intuitive thought. It could turn out that I don't have a clue about any of this. (Pencil/eraser theory) I didn't do the math yet (maybe I'll have time after I tear the trailing arms out). I have found that everything, suspension wise, was worn, as can be expected on a 26 year old SC. I think the trailing arm bushings will have a story to tell, also. I'm very curious to see what they look like.

I have also found that experience is the best teacher. Many of you fellow readers have a lot more eperience with this than I do.

Pat

[HarryD]

FWIW, I superglued the bushings to the Springplates.

[Tyson Schmidt]

I really doesn't matter which method you use.

Why? Because the grease will eventually squeaze out, and the rubber will bond to the spring plate anyway.

What the silicone grease does, is ease installation, and dramatically speed up the settling process, which makes it easier to corner balance the car right after the suspension work is done.

[patkeefe]

Well, I thought I'd get the trailing arm out by now, but the left half shaft put up a good fight. When you get the rubber bellows loose, and the once heavy grease runs out like 80 weight, that's not good.

However, now that the trailing arm is unrestrained, it does have about 1-1/2 to 2" lateral play. Does this sound normal? The bushings look shot, but I'll know more tomorrow.

[patkeefe]

Thanks, Tyson. That logic makes perfect sense to me, and it does have to be aligned as soon as it's back together.

[Neilk]

Pat, with regards to what Tyson wrote, when you set your spring plate height, don't be surprised that it will be too high. Once you drive it a bit, it will settle a good 1"+.

[patkeefe]

Neil:
It took a bit of research to find the spring plate angles for the 27 mm bars. (Thanks to Zeke and Will for that info) Think I should set the angle a bit flatter to compensate? Will the silicone lubricant make up for the initial height difference? I'd like to avoid setting the rear ride height, and then doing it all over again.
Thanks!
Pat

[notfarnow]

When I saw the title of this thread, I expected to see this picture:

[randywebb]

Pat - do you have adj. spring plates? If not, get them - makes it easy to set the ht.

[HarryD]

Originally posted by notfarnow
When I saw the title of this thread, I expected to see this picture:

So...whats wrong with a Hillbilly engineering repair???