Vague Steering

PCC · #1 (**permalink**) 07-09-2005, 04:03 PM

Not an easy subject to get a simply answer............

I would like to find out what's causing my steering to act in a "vague" manner (bit like my mind).

When driving on an "uneven" surface (most of QLD roads) I find that the steering has a tendency to wander (feels light) and can quite easily pull to the left (if you dont have two hands on the steering wheel).

Lifted the rear suspension, but does not seem to improve things.

Running with jag front and back (single coilovers on the back).

I do find that the car does handle very well on a smooth surface and sticks like glue. It only accurs on undulating surfaces or at high speed (dangerous).

I'm wondering if its something to do with the flexibility of the chassis, but thats only guessing.

I think I may have to get the suspension setup professionally and check the alignments. However not keen to throw money into an area that I have'nt got the answer first.

Thanks guys

boxhead · #2 (**permalink**) 07-09-2005, 05:17 PM

You may not have enough caster set into the front geometry or I have seen cars with zero toe-in exibit this feeling.

edwhite7 · #3 (**permalink**) 07-09-2005, 06:46 PM

What tires are you using?
I have this same problem with the Goodyear Eagle bias plys but I did not have it with TA radials. I would be interested in knowing if there is a way to correct this since I love the look of the tires and they stick like glue but the wandering is often quite scary. I do have a little less caster to keep the steering from being heavy.

PCC · #4 (**permalink**) 07-09-2005, 11:32 PM

David,

So I presume your suggesting an alignment setup is required?

I'm now happy with the visual setup in that the car is now slightly higher at the rear (makes for no scraping now!!).

Ed - I'm running radials and am sure its not the tyres. The car was originally setup very low and the handling was perfect. Just was not practical driving on Aussie roads!!

Lifted the front and now rear, which probably resulted in the alignment now being out.

David,

Can you take it to any retail outlet or is it a job best left to a specialist?

boxhead · #5 (**permalink**) 07-10-2005, 12:37 AM

Did you get another alignment after raising the car?
If you didnt then this will certainly be the cause of your problems, raising or lowering the car will have changed all your alignemny settings.

Rebel1 · #6 (**permalink**) 07-10-2005, 02:51 AM

Pete, I personally like a bit more caster than recommended.

Caster is what makes the wheel self center and also what helps the wheel track straighter. Too much makes for heavy steering at low speeds. But it is a matter of getting it all right.

Give Fulcrum suspension at Moorooka a call. They have done a lot of cobras.

The guy that owns the place..can't remember his name.

Cheers

NASSTY · #7 (**permalink**) 07-10-2005, 09:43 PM

Peter,
Also worth checking the steering rack bushes on the the Jag rack. (I assume that's what you are using.) The rack may be moving sideways in its mounts which causes vague steering response particularly if you are turning the wheel and initially the response is vague/slow to react.

Good luck

David Hodgson · #8 (**permalink**) 07-11-2005, 04:02 PM

Pete
Daves right about the caster and toe settings. When I got mine on the road I had it set up with conservative settings like a sedan and it behaved well on the road, I then set zero toe same caster and a bit more neg camber for track work. Very responsive and less understeer on the track, but diabolical on back roads.
Increasing caster will have two effects, first as Les says helps straight tracking, and also exaggerates neg camber on turns(leaning in at the top of the wheel).
Zero toe will aid turn-in response by increasing toe-out on turns, but can unduce wandering in straight ahead, so keep some toe-in.
Exact settings will vary depending on what donor front end as kingpin inclination and control arm angles vary on different makes.