911 rear end slide out. what speed ??

[MrScratch]

Hi Guys
new owner of my 84 Cab
Just got a new set of Mich AS4 on 205 55 r16-225 50 r16
I am just wondering at what general speeds should i watch my rear to go?
i'm sure the car should hold down at regular posted highway speeds?
But what about those tasty little on/off ramps with diminishing radii etc?
i did look it up and do find a lot of info but i'm not racing. i might push it in corners about 10-20 kph over if it's empty or i can see the other side but i almost feel like i can corner in my 06 Rubicon faster without freaking out!! lol
advice and tips?

[shoooo32]

Considering we're discussing a 40 year old car that has likely experienced suspension and alignment changes since new, pinpointing the exact speed the car will break loose would be very difficult. Taking into account weather, road conditions, driver inputs, etc... this would be tough to nail down.

My advice: find a large, empty parking lot and slide the car around. You could attend a formal autocross, but 15 minutes in a parking lot will tell you what you want to know.

[jac1976]

Do you warm the tires before hooning? Getting know the car will help you modulate the throttle.

[pgeorgeson]

There’s no way to answer that question with speed alone. You can spin a 911 at 20 mph and also drive it perfectly through a corner at 120+.
Take it to an autocross! That is the best way to play with the limits in a safe environment (and to learn how to drive it while you’re at it.) .

[icarp]

The reputation for a 911 to be more tail happy is a false one . Any car will loose the front or rear end as the limit for traction is exceeded .
It has to do with the way the car has been aligned , ride height ,tires , sway bars ,tire pressure .
A front drive honda or any front drive car can swap ends in a blink .
Driver input is also at the top of the list , the car only does what the driver asks for .
I think you should sign up for auto cross , Porsche driving DE events , or true driving classes .

My guess is you do not have any real driving experience at the limit of any car .
Go to school so you do not crash your car

Ian
why do i have this opinion ? look at my profile .

https://www.google.com/search?q=ian+rs+911+clone&oq=ian+rs+911+clone&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIGCAEQRRg90gEIODA0MG owajeoAgCwAgA&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:38ba29fd,vid:MPVV04V7Zcc,st:0

[darrin]

MrScratch -- be sure to read up on the physics of our rear engined cars - i.e. how weight-shift from braking/acceleration can have a unique effect. The easiest way to get into trouble is to enter a turn too fast, suffer understeer and then hit the brakes to slow down. Doing this will transfer grip away from the rear tires to the front and cause the rear end to swing around like a pendulum. "Slow in, fast out" (drive into a turn slower than you think you could and accelerate through the turn) is a good mantra to follow. Also, strongly suggest that you get some autocross experience and/or a PCA driver's ed/track day program or 3 under your belt to help fully understand the unique handling traits of our 911s.

Also, what size tires did you end up going with? you mention 215 width tires up front? 205/55-16 is the stock width for front tires, if you have 215s up front keep an eye on their sidewalls for evidence of scuffing on the inner front fender lips and roll your inner front fender lips as soon as you see any evidence of scuffing to avoid damage to both your new tires and the fender lips/paint

Finally, keep in mind that new tires generally require 5-600 miles of use before the greasy coating applied during manufacture to allow the tires to release from their mold wears off. Suspect you'll find your tires' performance to improve significantly as they break in.

[David Inc.]

It doesn't sound like you're driving aggressively enough to be worried about this sort of thing at all. If you're pushing it more in a Rubicon than a 911 you're just fine.

If you want to find out, do a driving course and get an instructor to whip you around on track at speed.

[MrScratch]

Originally Posted by shoooo32

Considering we're discussing a 40 year old car that has likely experienced suspension and alignment changes since new, pinpointing the exact speed the car will break loose would be very difficult. Taking into account weather, road conditions, driver inputs, etc... this would be tough to nail down.

My advice: find a large, empty parking lot and slide the car around. You could attend a formal autocross, but 15 minutes in a parking lot will tell you what you want to know.

thanks! hard to find one here with no cars in it or speed bumps and parking blocks.
i'm also talking about regular driving. like highway speeds. not so much track.

[winders]

Originally Posted by icarp

The reputation for a 911 to be more tail happy is a false one .

Define "tail happy".

Let's be real here. Lift throttle oversteer is a real thing with rear engine and mid engine performance cars setup to handle neutrally. It is more prevalent with rear engine cars. The 911 is well know to be prone to lift throttle overseer.

So, if "more tail happy" includes lift throttle overseer, then the "more tail happy" reputation of a 911 is not a false one...

[MrScratch]

Originally Posted by darrin

MrScratch -- be sure to read up on the physics of our rear engined cars - i.e. how weight-shift from braking/acceleration can have a unique effect. The easiest way to get into trouble is to enter a turn too fast, suffer understeer and then hit the brakes to slow down. Doing this will transfer grip away from the rear tires to the front and cause the rear end to swing around like a pendulum. "Slow in, fast out" (drive into a turn slower than you think you could and accelerate through the turn) is a good mantra to follow. Also, strongly suggest that you get some autocross experience and/or a PCA driver's ed/track day program or 3 under your belt to help fully understand the unique handling traits of our 911s.

Also, what size tires did you end up going with? you mention 215 width tires up front? 205/55-16 is the stock width for front tires, if you have 215s up front keep an eye on their sidewalls for evidence of scuffing on the inner front fender lips and roll your inner front fender lips as soon as you see any evidence of scuffing to avoid damage to both your new tires and the fender lips/paint

Finally, keep in mind that new tires generally require 5-600 miles of use before the greasy coating applied during manufacture to allow the tires to release from their mold wears off. Suspect you'll find your tires' performance to improve significantly as they break in.

Hi thanks!
yes the care has 205 up front and 225 in back, my mistake.
that is also what is on the tire size sticker on the car.. on 16" rims.
my question was more along highway driving.
here in BC, we have a few winding highways with anywhere from 80-120kph limits.
i just was thinking that i should not have to be breaking into corners at speed limit speeds on a highway in a Porsche? lol
i don't speed really and not interested in smashing my new car up or getting it impounded by the boys for doing 40 over..
just looking for reassurance that my high performance german sports car can take corners at highway speeds lol

[Bill Douglas]

Ah ha. Now is the time to go to a race track.

I don't mean driving like you want to be the next Michael Schumacher, but just going a bit faster than you would on the street. A great way to learn just what a great handling car you actually have and what % of maximum you are driving at.

Around here we have whats called "Track Day" and every and anyone can drive on the track for 15 minutes for $25. Lots of boy racers but they are very respectful of others cars. Then we have "Practice Day". Practice day is for real drivers LOL to practice a week before a serious race. Still only about $75 but they didn't really want us amateurs on the track so we raced around when the big dogs weren't busy.

[David Inc.]

Originally Posted by MrScratch

Hi thanks!
yes the care has 205 up front and 225 in back, my mistake.
that is also what is on the tire size sticker on the car.. on 16" rims.
my question was more along highway driving.
here in BC, we have a few winding highways with anywhere from 80-120kph limits.
i just was thinking that i should not have to be breaking into corners at speed limit speeds on a highway in a Porsche? lol
i don't speed really and not interested in smashing my new car up or getting it impounded by the boys for doing 40 over..
just looking for reassurance that my high performance german sports car can take corners at highway speeds lol

Uhhhh yeah you're fine. Unless you're approaching .8g or above and playing with the throttle while going down the highway you're not going to be having any problems.

[Matt Monson]

No advice on the internet can replace seat time in the car. Go drive your car and learn it inside and out before you explore the limits. Take a high performance driving class with a local track group. Practice. Then enjoy the fell out of your car.

[Tyson Schmidt]

"How long is a piece of string?"

But seriously, I agree with the above suggestions to find out for yourself in a safe environment.

[tobluforu]

Get yourself in a nice big parking lot and have at it. Or if your area runs auto-x days, sign up and have a blast. An experienced driver in the passenger seat will push you if need be. Then at the EOD, have one of those experienced drivers, drive your car and you will be amazed at what your car can do.

[andino]

There's no exact answer for this. Conditions determine limits and as those are always in flux, you can't make a blanket statement for such a thing.

Sign up for some autox and find the limits if your car in various conditions. Seat time is the best way to learn limits. Don't find them on the street.

[MrScratch]

Originally Posted by tobluforu

Get yourself in a nice big parking lot and have at it. Or if your area runs auto-x days, sign up and have a blast. An experienced driver in the passenger seat will push you if need be. Then at the EOD, have one of those experienced drivers, drive your car and you will be amazed at what your car can do.

will sign up but i have a cab. i think i have to have a roll bar?
that's a summer thing.
got a local
shop that can build one apparently.

[ccallana]

Originally Posted by MrScratch

Hi thanks!
yes the care has 205 up front and 225 in back, my mistake.
that is also what is on the tire size sticker on the car.. on 16" rims.
my question was more along highway driving.
here in BC, we have a few winding highways with anywhere from 80-120kph limits.
i just was thinking that i should not have to be breaking into corners at speed limit speeds on a highway in a Porsche? lol
i don't speed really and not interested in smashing my new car up or getting it impounded by the boys for doing 40 over..
just looking for reassurance that my high performance german sports car can take corners at highway speeds lol

Look at it this way - if these cars couldn't handle normal roads, at normal (or even slightly above normal) speeds - this forum would be more of a "hey, remember that cool 911 from back in the day" - all of them would have been crashed already

If you are a "follow the posted speed limit" driver, you are fine ... 67 Beetle can handle that just fine ... your 911 should have no problem.

[icarp]

Originally Posted by winders

Define "tail happy".

Let's be real here. Lift throttle oversteer is a real thing with rear engine and mid engine performance cars setup to handle neutrally. It is more prevalent with rear engine cars. The 911 is well know to be prone to lift throttle overseer.

So, if "more tail happy" includes lift throttle overseer, then the "more tail happy" reputation of a 911 is not a false one...

"Scott you ignorant slut "
It would seem you have never driven a front wheel drive Acura Integra , Honda Civic ,VW Golf in race car trim or proper street trim. The difference between FWD and RWD
is not what will happen, it is is how do you recover .

It is Physics that dictate the oversteer , understeer, action of any and all cars .

The rear engine car may tend to have a stronger secondary momentum habit .

It would seem that you have forgotten, for general purposes ,weight equals traction


Ian

[pmax]

Originally Posted by MrScratch

...
But what about those tasty little on/off ramps with diminishing radii etc?
...

The last 911 I saw "off road" was a late model water cooled variant next to one of those ramps, a couple years back.

Yeah, good tires but ...