Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 road holding

A wobble on the Morgan IFS can be caused by so many different factors , the tyres are the most obvious and a higher pressure will reduce this.

Once you have confirmed the geometry is correct , equal and you have got as much negative camber as the system will allow (if adjustable) then start increasing the front tyre pressure. When on road tyres in my +4 (with a heavy TR engine so not really comparable) I used to race on 38 psi front , and 36 psi rear. I don't recommend going that far on the road unless you have a very friendly dentist, but definitely go up in 2 psi increments on both front and rear until you find "the sweet spot" (grip v ride comfort) and then try adjusting the differential. I still stand by a 2 psi positive delta in the fronts , BUT your driving style may be completely different to mine.

I agree with K that 20 psi is too low for "spirited" driving , I am guessing it will be in the 26 to 28 range. At 22 psi the tyre walls will distort badly with high cornering forces.

The stub axle itself actually distorts under hard cornering , and this is especially the case with slicks and competition tyres where the grip available at the contact patch is greater than the force needed to "bend" the spindle. This is an extreme example and not likely to be encountered on public roads.

Have you sorted out the rear axle. In that fitted a panhard rod etc. my car used to “wobble” going around corners which I thought was bump steer. Not there at all now since the back end has been done. Did not realise how much the rear axle was moving about.
Just a thought.

I have experienced front end “wobble” on my own car and several others that I have driven over the years. Typically when cornering briskly on perhaps slightly uneven road surfaces. Rather than wobble, I might describe it as “skipping”. One might suggest that it is a Morgan characteristic emanating from ancient suspension design.
However, on my own car, with SSL front suspension, even with new king pins etc, after some 5k miles, the problem was still there. I found that there was too much pressure on the rebound springs. Adjusting this as per SSL instructions made a huge improvement.

Deejay, you are right! My front end problem is closer to "skipping" than "wobbling"

The jiggly corners was one of my motivators for trying a damper.

On mine I have AVO front shocks, brake steady bars, 4 pot calipers, new rear springs, uprated Armstrongs (variable damping) a Panhard Rod, wider wheels and fat tyres (22psi all round)

Handling has been transformed. No skitting, or skipping and can hit corners at far higher speed than before. She is very planted.

I'm not a racer, but try and keep to a consistent speed - 65mph on the straights, and the same round the corners. I find it very frustrating when you get people in the usual german PE sport saloons who boot it on the straights but seem unable to use the steering wheel when they get to a corner....

I call 'em 'dabbers' as they seem to keep hitting the brakes at random unnecessary points

Hi,
If it's a sharper turn-in you want (ie a more over-steery car) just try reducing the toe-in. In my view the standard settings are excessive. I run my Plus 4 with very little toe-in, almost parrallel, and its turn-in is much improved.

My settings for the 4/4 if anyone is interested. Seems pretty good on track, although would have liked a bit more camber, but it wouldn't go.

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I call 'em 'dabbers' as they seem to keep hitting the brakes at random unnecessary points[/quote]

Comfort braking