Why is my C2 unstable? Near Death Ride

[fly]

Hey All
I recently purchased a 1991 carrera with 100k on it. Had it check by a local guy and mechanically passed the tests. Anyway, I have had several porsche models over the years, this is my first 911. I admit I am new to the rear engine and the unique handling features.
The previous owner install Koni shocks, non adjustable 3 months ago. The pads are new but the tires are bald. Here is what happend.

Last week I was entering the freeway on ramp. It curves to the left as it goes up hill. The on ramp is 2 lanes that merge into one lane midway. As I accelerated to pass a car I took the outside lane. keep in mind it is not a sharp turn and perfect for gaining speed before entering the freeway, As I passed the car on my left the car broke loose and started to slide at 50MPH. In an instance I found my self facing headlights of the car I just passed with a full right corection. At this point I let my foot off the gas, I never stepped on the brakes. I then started 2 vialent spins in the oposite dirrection each time correcting to avoid hitting the gardrails and traffic. After 2 and 1/2 spins, I found myself pointed in the correct direction and accelorated onto the freeway. Somehow, Magically, I never stopped or hit anything and the car seams perfectly fine.

Before you remark, I know that letting my foot off the gas was not the best thing to do. However, I was accelerating through 50mph when the first 180 accured.
after that I did what I could to avoid or at least soften the impact.

I want to know, Is this a common thing with these cars? Keep in mind this on ramp can be taken at 50mph with my truck no problem. Yes the tires have very little tread but I cant believe this would be the only reason this car would spin out of control. Not having anything to compair with I feel there is too much road noise and should get better with new tires.

Are the struts wrong or is it a combination of things,
I can take my 928 around this curve at 110 with no trouble and my mid engine 914 as fast as I can get the car to go.

I am not interested in a Porsche that is unstable at low speeds.

Any ideas or feed back will be helpful with my decision to keep it or sell it.

Thanks
Fly

[fly]

I dont have a current photo of the 911 so here is a photo of my 75 914
it seems to out handle most cars.

[mrk_d]

Seems like pushing a brand-new (to you) car with bald tires might be your problem. I have driven 928s, 914s, and 911s and they all handle differently, but there's no way you're going to be able to more than double your speed for a given corner between a 928 and 911 if the setup is good in both cars. Sounds like you need to get new tires and then slowly get acclimated to the handling. Do you really think a proper 911 would be slower in a corner than a truck?

[vracer]

Race cars run on slicks, so that isn't it. The tires could be hard as rocks. There could have been an oil slick or some other liquid there, or something very wrong in the suspension.

[DRACO A5OG]

Was the ramp a little off camber? I tend to slide out going on the ramp on the 110 north off of 8th in downtown, I learned to control it and I have LSD to boot.

[fly]

a couple more for fun It is only a 1.8

[Flieger]

I bet it is the tires. Put some nice RA-1s, Kunho Ecsta V10, Yokohama Advan A048, or similar on there.

It is not so much the lack of tread as the rubber compound and age. What kind of tire are they?

[vracer]

Good lookin' 914. You may have killed one too many trees for my taste, but that is as about as good as a 914 can be. I did the sail panels the same way on my '73 2 liter. Most fun car I ever owned.

[fly]

Originally Posted by mrk_d

Seems like pushing a brand-new (to you) car with bald tires might be your problem. I have driven 928s, 914s, and 911s and they all handle differently, but there's no way you're going to be able to more than double your speed for a given corner between a 928 and 911 if the setup is good in both cars. Sounds like you need to get new tires and then slowly get acclimated to the handling. Do you really think a proper 911 would be slower in a corner than a truck?

I agree that it is new to me and I need to learn how to handle the car better. I wasnt trying to race I felt I was driving reasonable. I checked it the next day and the road was a bit bumpy but nothing else.

Is it possible tht the bad tires and too stiff suspension could have caused it to skip and start the slide? If I put new tires, do you think I will see a big change in the car?

Thanks

[andrew15]

My first thought would be tires - if they are bald, they may also be pretty hard with almost no traction.

Next up would be the gas pedal - yes, it tossed you around later, but did you 'stomp' on it to pass the other car? Did you lift off to shift and then get back on it hard while passing? The 911 is a bit different than most cars - it prefers slow in, fast out of corners, basically accelerating post apex as you are unwinding the steering wheel. Adding more gas and more steering at the same time is a ticket to spinsville in a 911.

The only other thing I can think of is fine sand / dust, etc on the edge of lanes - maybe you got into the dusty area and lost some traction?

I vote for #1 though - Get some new ties and enjoy the car

Regards,
Andrew M

[5String43]

Your car might need an alignment. I know that mine certainly did when I got it - it wanted to throw itself off the road. It's fine now. So: Try it with decent tires and a full alignment.

[fly]

Originally Posted by vracer

Good lookin' 914. You may have killed one too many trees for my taste, but that is as about as good as a 914 can be. I did the sail panels the same way on my '73 2 liter. Most fun car I ever owned.

Thanks for the compliment, It was a lot of work and the burl wood is not real. It is a faux finish we use in our aircraft interior company. The armrests are fiberglass with power windows.

Sorry about the 914 pics with a 911 question

[McLovin]

Originally Posted by fly

As I passed the car on my left the car broke loose and started to slide at 50MPH.


I can take my 928 around this curve at 110 with no trouble .

It's because the 911 is just a regular car, the 928 is a true exotic.

[fly]

Originally Posted by andrew15

My first thought would be tires - if they are bald, they may also be pretty hard with almost no traction.

Next up would be the gas pedal - yes, it tossed you around later, but did you 'stomp' on it to pass the other car? Did you lift off to shift and then get back on it hard while passing? The 911 is a bit different than most cars - it prefers slow in, fast out of corners, basically accelerating post apex as you are unwinding the steering wheel. Adding more gas and more steering at the same time is a ticket to spinsville in a 911.

The only other thing I can think of is fine sand / dust, etc on the edge of lanes - maybe you got into the dusty area and lost some traction?

I vote for #1 though - Get some new ties and enjoy the car

Regards,
Andrew M

Makes sence. I do know I didnt change speed passing the car. It wasnt an issue.
I will put some new tires on it and see how it feels. No one seems to be concerned about the stiff shocks. Do you think with new tires the shocks will be fine? or should I go to an OEM strut?

[fly]

Originally Posted by McLovin

It's because the 911 is just a regular car, the 928 is a true exotic.

[DRACO A5OG]

and much heavier, no?

[rusnak]

Wow, I think I'd really like to see that 914 someday in person. Never seen so many trick mods on one before.

[fly]

Originally Posted by rusnak

Wow, I think I'd really like to see that 914 someday in person. Never seen so many trick mods on one before.

Always happy to show off one of the toys. I spent alot of time over two years building it. I am in the San Francisco Bay Area. When I purchased the car, it was a mess and my wife wanted me to "throw it away" Now she wants to keep it.

[Flieger]

I doubt that any non-adjustable Konis could be so stiff as to make the car skip off the road. Overdamped possbily, but not dangerously stiff.

Tires

Alignment

Corner Balance

in that order would be my plan of attack.

By the way, you might try posting this in the 964 section, since the guys there might have more experience with your specific car and modifications.

[Geronimo '74]

Lol, you won best interior??

Great looking 914, too bad about the wood...

Flieger said, tires first!!