Fitting softer springs??

[William2]

I currently have Tony Thompson 95Lbs 12" 2.25" rear springs on adjustable perches fitted to my road use only S4 Elan. I am finding the ride comfort a bit hard and was thinking of fitting a pair of Faulkner 12" 75Lb springs. I believe the original Elan springs are rated at 67.5Lbs. I realize that having TTR 95Lbs springs on the front that there will be a small difference in front/rear spring ratings but would imagine that this is not a problem for normal road use. For information, the rear dampers are non adjustable Armstrongs and the front are TTR fast road use adjustables set on their minimum setting. Does this softer spring sound a feasible trial and has anyone else fitted 75 or 80LB 2.25" rear springs without any problems such as height adjustment or coil?

[ecamiel]

Spring rates are probably not causing your harsh ride problem. Look to bump stops, tire pressures. "stiction" in old suspension bushings and shocks. Look at top bushing for shocks front and rear (locotone)
How old are the bushings?

Eric
64 S1

[William2]

Hi Eric, all the suspension has been rebuilt with new Lotocones and rubber suspension bushes. Tyre pressures are all as they should be. I just remember that a previous S4 Elan I owned which had all standard suspension had a much softer ride.

[webbslinger]

If you haven't already done so, try stiffening up the shocks first. I'd try going to half way or more at first to see the difference.

[webbslinger]

I missread your question and thought you were asking about the front. My very limited experience is with 115# front springs with adjustable Spax, and 95# rears with difficult to adjust Konis. I started out with the dampers set very soft and it had a lousy harsh ride. When I asked about it, a friend suggested stiffening the dampers instead of going softer. My car responded well to fairly stiff damping in front and moderate in back. I focused on your mention of full soft on your front dampers which was way off on this car.

[UAB807F]

Spring rates are probably not causing your harsh ride problem. Look to bump stops, tire pressures. "stiction" in old suspension bushings and shocks. Look at top bushing for shocks front and rear (locotone)
How old are the bushings?
Eric
64 S1

I think I'm in agreement with Eric, the increase in spring rate sounds a lot in % terms but probably not so great in the overall scheme of things. If the platforms are adjustable, how is the ride height looking ? (I'm wondering if there's not too much pre-load on the springs)

In your post you mention 95lbs at the front as well, which came as a slight surprise because most packages I've seen have had a slightly higher front spring rate than rear due to weight distribution, operating angle, etc, so seeing the same rate all round is new to me.

If that is the case then lowering the rear rates for a trial sounds reasonable. However if the fronts are more like 115 lbs then I personally wouldn't change the rear spring rates without a corresponding change in the front spring rates.

Changing the rear alone won't be tragic and no problem on the supermarket shopping run but at some point you'll be cornering faster than that

Brian