63_ Understeer

[Steve D.]

63 convertible, radial tires, stock suspension, power steering

Among the many things on my shakedown list is what I perceive to be a significant understeer condition. By that I mean when going through a mild curve at 30 to 40 mph my perception is that it takes noticeable effort to pull the car through the curve. I don't have this perception when turning corners. I have not had a proper alignment done yet, only my efforts to get things as straight as possible. The car doesn't shimmy, nor does it pull to the right or left. Is this indicative of some known set up issue, or do I need to have the alignment done before assuming that there even is an issue?

Steve

[Jim L.]

Re: 63_ Understeer

63 convertible, radial tires, stock suspension, power steering

Among the many things on my shakedown list is what I perceive to be a significant understeer condition. By that I mean when going through a mild curve at 30 to 40 mph my perception is that it takes noticeable effort to pull the car through the curve.

Unless you are cornering at the limits of adhesion, you can't evaluate whether the car is understeering or not.

I'm not sure what you are experiencing from your description. Maybe you are just outrunning the ability of the PS system to keep up with your steering inputs.

I, too, have a '63 roadster with PS and radials. I don't notice anything like what I think you have described.

Jim

[John H.]

Re: 63_ Understeer

I have not had a proper alignment done yet, only my efforts to get things as straight as possible. The car doesn't shimmy, nor does it pull to the right or left. Is this indicative of some known set up issue, or do I need to have the alignment done before assuming that there even is an issue?

Steve

Steve -

It's way premature to make any assessments of handling until a proper alignment is done.

[Steve D.]

Re: 63_ Understeer

Thanks; I'll get the alignment done.

[Steve D.]

Re: 63_ Understeer

Jim

I am probably misusing the word. In my useage, I think of understeer as the tendency of car to leave on the tangent of the curve and oversteer as as the tendency to nose to the inside of the curve.

Steve

[Stuart F.]

Re: 63_ Understeer

My 63 has radials, but no power steering and has been set up for the faster steering ratio since new. The alignment was done when the radials were added by a Corvette specialist experienced in older C-2's converted to radials. All that aside, I too share the "understeer" perception in the longer sweeping turns at speed that requires a fair amount of steering input - enough so that I don't feel comfortable to approach the limits of adhesion (by the way, did I mention I'm getting old too). I can't say now that I ever considered my car a good handler even with the old 6.70x15 bias ply tires either, primarily because most of the cars I had in the early days were oversteering tri 5 "hot rods" that I used to "dirt track" around. With the 63, every time I drove it aggressively I got in trouble. My favorite trick was spinning it out at highway off ramps and backing it into the brush. I broke a rear spring and strut doing just that once.

Stu Fox

[Jim L.]

Re: 63_ Understeer

Jim

I am probably misusing the word. In my useage, I think of understeer as the tendency of car to leave on the tangent of the curve and oversteer as as the tendency to nose to the inside of the curve.

Steve

Steve, your impression of the two conditions isn't wrong.

And, in fact it's possible you are sensing what's called "roll understeer". You turn the steering wheel and the front wheels initially change direction in proportion to your steering input. But, as the body rolls and the suspension moves, the outboard front wheel could be straightening itself which you experience as an unwillingness to turn in.

True understeer happens when the front end of the car loses grip before the rear end loses grip. If this were happening, your front tires would go sliding off the road while your rear tires happily follow along. I don't think this is what you are feeling.

There is also a phenomenon known as "roll oversteer", the effects of which you can imagine, and it is truly unnerving.

As to what to do for your car, having all four corners aligned, as John suggested, is the first step I would take.

Jim

[Duke W.]

Re: 63_ Understeer

All cars understeer to some degree, and it becomes more noticeable as you reach the limit of adhesion, but from your post I wonder if you are confusing understeer with steering effort.

Properly set up C2 small blocks exhibit very mild understeer compared to modern FWD cars and can quickly transition to oversteer at the limit.

They can be a handful at the limit for inexperienced drivers.

Duke

[Bill M.]

Re: 63_ Understeer

Jim

I am probably misusing the word. In my useage, I think of understeer as the tendency of car to leave on the tangent of the curve and oversteer as as the tendency to nose to the inside of the curve.

Steve

You can induce more limit oversteer by disconnecting one end link on your front sta. bar. Take it easy and sneak up on the limit; it should want to spin.