Why does my car handle funny?

TRE Cup · TRE Cup's Garage

This was the question posed to us from the owner of a nice Carrera RS clone. "So when does this funny handling occur?" we asked. "Whenever l take a curve at any kind of speed, the back of the car feels really twitchy!"

Ok- we took a look at his spring plates and this is what we found:
Very important that you guys (and gals) check that the rear bushings are in good shape. In this particular case, we had to replace the cups, spring plates, and torsion bars since so much sagging and wear occurred. Not to mention that an uncontrolled rear suspension is a safety issue as well.

Wil Ferch · 03-03-2005, 12:02 PM

I presume you removed the spring plate covers so we can see the damage to the bushings...right?

I mean ...they weren't *missing*.....were they?.....or?

Wil

ckissick · 03-03-2005, 12:04 PM

Was the damage so glaringly obvious when everything was put together? My car handles fine, but the t-bars are sagging a bit on the bushings. I may have a new project on my hands.

The engine runs great, though. Thanks, Dave.

Chuck Moreland · 03-03-2005, 12:22 PM

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!

widebody911 · widebody911's Garage

Ok, that settles it! No more fat chicks!

Oldporsche · 03-03-2005, 03:03 PM

As soon a warm weather comes, I see my next project.

David Duffield

North Coast Cab · North Coast Cab's Garage

The same thing happens in the front. If the bushing have "flowed" the t-ar car rub and cause a binding feeling up front. Both are cheap and fairly easy to do, though they take a good day worth of grunting.

John

Plavan · Plavan's Garage

Quote:

Originally posted by widebody911
Ok, that settles it! No more fat chicks!

Thats funny coming from you Widebody

toolman · toolman's Garage

I am going to do this soon, so what is the best plan of action. What bushings do I use for mostly street? Banana arm bushings too? What else while "I'm in there" stuff.

einreb · 03-03-2005, 04:11 PM

As a data point.... here's the spring plate bushing from an '88 with 118k miles on it... you can see the deformation, but its not that bad. I ended up having them zinc plated and putting chuck's bushings on it.

cstreit · cstreit's Garage

Heh heh...

This one reminded me of a car I just did...

Customer: "Why is the brake pedal not returning back "

Hmmm.... Lets look at the pedal cluster... Ohhhhhhh...

Tim Walsh · Tim Walsh's Garage

Hey that looks familiar.. 2 years with clogged sunroof drains and sitting outside will do that.

randywebb · 03-03-2005, 04:32 PM

It's not the 118k miles on it, it's the age of the car - i.e. the # of hours it has spent putting wt. on the rubber, whether driven or not.

TRE Cup · TRE Cup's Garage

how it looks now

pwd72s · 03-03-2005, 04:40 PM

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.

Fishcop · Fishcop's Garage

Dave, in general, what do you recommend replacing the original bushes with? Factory rubber, poly or poly-bronze?

Grady Clay · 03-03-2005, 05:32 PM

Paul has some good advice here.

Best,
Grady

Victor · 03-03-2005, 08:15 PM

I take it that's a Targa pedal cluster?

TRE Cup · TRE Cup's Garage

Factory rear rubber bushes used to be available from the dealer for the 68 and earlier cars. Don't know if those are available anymore. We really like to install The Elephant Polybronze for any type of performance oriented 911 (and 914) owner.The neatrix replacement rubber bushes for street or clients on a tight budget. If the client is prone to deferred maintainance, the Neatrix also gets the nod.

I am not a fan of the poly urethane bushes for the control arms. Though they are good for sway bar mounts, we have seen too many plastic bushings seize in their mountings, and fret away from the friction. Who needs uncontrolled added "spring rate"? Worse yet- we have seen several failures of the inner rear control arm plastic bushes on race cars- now who was driving that forklift?!
We mount our bushings (neatrix too) with proper grease to aid in free movement of the suspension.
IMHO- we have been very happy with the Elephant bushing kits and believe them to be one of the most important parts of repairs/restoration that one can do to an old suspension

MotoSook · 03-04-2005, 07:44 AM

Quote:

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.

And what was the final formula?