911 understeer?

[raceral]

Just recently purchased a 85 911 coupe with 74k miles. I've always heard about the dreaded 911 oversteer problem, but I seem to have the opposite problem. At 7-8/10ths on the road, the car gets harder to turn into a mid speed curve. i have 17" wheels with 225/45 F and 255/40 R. Is it posible these are too big? I havent had it aligned yet, but I recall from my auto-x days that a little toe-out helps on turn in. Is this a good idea? Thanls.

[Zeke]

First, welcome. I'm not the handling expert around here, but I'm a new Carrera owner as well. Used to drive a 71 S and before that, a 77 Targa, plus a couple of 914's.

AFA your understeer, that seems to be common complaint. I don't think I'd run toe out on the street much, too much darting. You can check your tire pressures and raise the rears a bit and see. Or, maybe the fronts are too high. You can experiment with that.

Are your sway bars OK? Sometimes the rear mounts break. I have the same tires and wheels, but I haven't pushed this car yet. Still getting the feel of it. I do have some negative camber built in by the PO, so my car may not be a good benchmark.

Sit tight and wait for some of the better informed. You will get your answers in spades.

Oh.....did you know you had to show a pic of your car to get any respect around here?

[A Quiet Boom]

I've got a '66 with the short wheel base which is supposed to be worse as far as oversteer. I've also got a lot of rear camber. What I've found is understeer on throttle and a touch of oversteer off throttle. I'm running a little less tire in a much lighter car, 215/45/17 front and 235/40/17 rear. Anytime the rear gets loose from off throttle I can bring her right back in line by mashing the pedal. I can also do the opposite if the car is pushing.

I'm no expert either BTW, these car just remind me of the ridiculous go-carts we used to build as kids (8hp what's that? I need a snowmobile engine LOL)

Oh and welcome to the forum and do post pics when you can.

[Dantilla]

To oversimplify:

Throttle on, understeer.
Throttle off, oversteer.

[stlrj]

It might surprise you the amount written on this subject when you use the search button.

[A Quiet Boom]

Originally posted by Dantilla
To oversimplify:

Throttle on, understeer.
Throttle off, oversteer.

Which is EXACTLY why I love these cars, especially when set up with well tuned carbs. Steering the car with the throttle is loads of fun.

[jazzbass]

If your car has a LSD, it will understeer a lot under throttle. It will understeer slightly into mid speed turns. It will oversteer in those same turns if you hit the brakes (see Dantilla's post). You tire setup is fine, but the tires could be old and crappy and not giving any bite to turn in.

[jester911]

The stock or close to stock setup of the suspension is designed with understeer. The oversteer claims are inflated. Really you don't feel oversteer unless you go hard into a turn and brake or if going very hard lift on the throttle.

These cars do however oversteer more in the rain. You really have to take it easier then.

[masraum]

Too, if you have a normal 911 alignment with lots of caster and decent negative camber in the front it will be hard to turn the wheel the farther off center you get. These cars don't have PS, so the camber and caster work to center the steering wheel any time it's not pointed straight ahead. The fact that you have bigger front tires just works to make the matters worse. The offset of the wheels can work to make things even worse.

And as others have said, the 911 understeers in most conditions. The oversteer issue that most people hear about is only when you do a couple of things. Don't ever let off of the gas or hit the brakes in the middle of a corner and you're unlikely to run into many oversteer problems.

[Wil Ferch]

Coupla things to add....

The "dreaded" oversteer...as you can see from a summary of the posts above...are "At the limit" ( for the conditions). Under normal circumstances the cars were set up by the factory to understeer as a compensation-type effort.

Note also that ( say..for track work or fast road work where you *are* closer to the limit)...the car behaves differently on high-speed turns ( meaning....the same high-g's but using a SMALL amount of steering wheel angle)...than it does in low speed turns ( same high-g's would require a LOT of steering angle input....rendering a less-optimal contact patch for the front).

My point?.....if you set up your car to be fairly OK ( neutral) for high speed turns....EXPECT a lot of low speed understeer. If all you do is drive on autocrosses or the highway...and you dial-out the understeer...expect a very "loose" ( or pucker-inducing) oversteering characteristic for high speed turns.

Lastly....the way you apply power in low speed turns needs to be "relearned" for a new 911 owner. Easy does it...no "mashing" on/off. A sudden application of power mid turn ( low speed) will create crushing understeer...better to ease-onto the throttle...you'll be amazed at the difference.

- Wil

[raceral]

Hey, thanks for the info guys! At least I know there's not something seriously wrong. Its just something I'll have to work on. Already checking prices on 21 or 22 sway bar for the back.

[Bill Douglas]

The other guys may flame me for this... I had a little understeer on the SC, only a little as SCs are probably the best handling car around ( ), and I got rid of it by puting stickier quality tires on the front.