Spring stiffness

[tim]

And how much does ones car way now with layers of Waxyol etc???

In the UK cars are weighed as part of the MOT and its on one of the MOT printouts.

My HF Series 2 weighs in at 1076kg's generally with a full tank, a full roll cage, and some tools in the boot.

I also strengthend the sills and have gp3 arch extensions and loads of waxyol so can expect it to be heavier than standard but was rather shocked that it tipped over the metric ton.

I would be interested in what other H series 2 HF's weigh in at?????

I sourced some brand new old stock series 2 HF rear springs from italy during my rebuild and the car does not sit up in the air and people have commented on how much more supple the rear end is compared to others. I put this to the test at the last cotwolds rallly where a number of HF's turned up and most were very stiff and somewhat elevated. I also have fitted a series one front spring which does lower the car somewhat at the front.

Tim

[Neil Cundy]

I included the load factor in my calcs, the only thing I am not sure of is the weight distribution front to rear ( I guessed at 40/60). As well I used the lower tolerences in the book for camber and applied load, so there is plenty of scope for variation, depending on the tolerence build up.
As well at the front, the relative "tiredness" of the rubber mount to the top wishbone will influence front ride hieght (not an issue at the back due to the shackles).

[Ed Levin]

Sorry, Neil, I should have assumed you'd taken the weight delta into account. Did you also adjust for the greater OA tire diameter for the S2? It won't make a bit of difference to the load calcs, but it would affect the appearance of body clearance at the wheel arches. And then there's Tim's point, which is that the factory's weight figure probably has oil and coolant but not fuel, which will add weight--and mostly to the rear.

But your assumption of a 60/40 weight distribution is very close to spot on; Road & Track calc'd 61/39 for an S1 1.3S coupe, and the HF cannot have varied by much. Because the coupes tend to have more weight-saving opportunities in the middle and rear than the front (plastic windows side and rear but not windshield, less upholstery, &c.), it's possible that the S1 HFs had very slightly greater front bias, but it can't have been more than a point or two.

In any case, I'll revert back to my initial guess that there are no two identical sets of springs at this point (nor, probably, very many that match the original design rates and/or camber). So the only answer to John's original question may be that all spring rates are equal, but some are more equal than others...

[tim]

Re front /back weight split, my MOT certificate indicates 63% front 37% back for s2 1600 HF with oil cooler.

Tim

[John Keppelman]

I discovered this thread too late to add much probably, but I went around the block with Fulvia springs racing my Zagato/Sport. The front springs would only last a couple years before they sagged onto the bump stops (and those were shortened). The fronts are a bear to get in and out - it usually takes two people - but I finally got pretty good at it. I eventually had a front leaf set made in Seattle to stock stiffness, and that one has lasted. We established a stock stiffness by measuring a good stock spring in a hydraulic press and calibrating by pressure gauge for a given diflection of the spring and had that replicated by a spring shop. I believe the best way to lower the back is to de-arc the stock spring, determining how much lower you want it and having a spring shop press that degree of camber out of it. No heating involved. That is unless you do want to change the spring rate by removing or substituting leaves.