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Old 03-02-2021, 02:21 AM   #1
sloopy
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Join Date: May 2020
Location: Dallas, Texas
Default wagon springs or ambulance springs with koni sport dampers?

I'm looking to buy koni sport dampers for my 240 wagon and want to know which rear spring would be a better match for my system. Currently I have lesjofors 4095801 on the front and lesjofors 4295816 on the rear. I took some measurements by measuring suspension compression with a known added weight of two friends over the axle.

I measured an effective spring rate of about 118 lbf/in in the front, which probably puts me in the ballpark of a 125 lbf/in spring. My camber is set all the way negative with the stock plates, although I didn't do the math and assumed a rough 0.95 motion ratio to get the 125 lbf/in rate. This makes me think these are basically gt springs.

In the rear, I measured an effective spring rate of about 222 lbf/in. With a motion ratio of 1.5, that puts me at almost 150 lfb/in for the rear springs, which seem more like ambulance springs than normal wagon springs.

Dave posted specs on the konis here: https://www.240turbo.com/suspension.html

koni sport yellow: rebound / compression (newtons at a peak velocity of 500 mm/s)
front strut: 950-1900 / 700
rear shock: 2200-4400 / 1150


My gut reaction is that I should ditch the ambulance rear springs and get normal wagon rear springs, but I figure there should be an objectively better choice based on the data.
__________________
1992 volvo 240 wagon:
> flavor: black on tan
> suspension: stock + 23/19mm f/r arb
> wheels: 14x6" enkei 92 + 215/70R14
> drivetrain: M47II + 3.31 + open diff
> engine: B230F + 2.5" exhaust

Last edited by sloopy; 03-02-2021 at 08:47 PM..
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