Handling issues - need adjustment advice |
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Handling issues - need adjustment advice |
Brian Fuerbach |
Jan 20 2022, 02:57 PM
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#1
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Member Group: Members Posts: 119 Joined: 1-July 19 From: Orange, Ca Member No.: 23,266 Region Association: Southern California |
When driving large sweepers like freeway on ramps at high speed I experience what I can only describe as front end scrubbing. Not understeer, more like the front is just not planted and tracking. Things get better with a full tank of fuel. Is that just the nature of the 914, full tank factored into weight bias, or can the suspension be tuned to emulate the weight.
Here is what Im working with; -19mm adjustable sway-bar set about 1” back from full soft. -Koni yellow adjustable shocks -Stock front torsions -Rear springs are aftermarket (reddish orange color) but I do not know the poundage. Any input would be appreciated. |
Superhawk996 |
Jan 24 2022, 06:40 PM
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#2
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914 Guru Group: Members Posts: 5,824 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
So I did a quick rationality check tonight using the highly scientific bathroom scale and tape measure.
168 lbs at 1.75" travel = 96 lbs/in for the 914Rubber 100lb/in spring. Pretty close. quick design comparison using an online spring calculator https://www.thespringstore.com/spring-calculator.html Design #1 close to 914Rubber 9.6mm wire diameter 105.5mm OD 380 mm free length (15 inches) 6 effective coils Result 90.795 lb/in (sorry for mixed units -- Imperial units for ease of comparision) Design #2 close to published stock data and the chart data above 9.6mm wire diameter 105.5 mm OD 470mm free length (18.5 inches) 10 effective coils Result 54.477 lb/in Design #3 published data from factory manual 9.6mm wire diameter 95mm mean OD -- this works out about the same 105.5 mm OD I measured directly 460 mm free length (18.1 inches) 10 effective coils Result 54.477 lb/in (IMG:style_emoticons/default/idea.gif) So I was wrong assuming that the chart data seemed low at 50's ish lbs/in rate. That is super interesting since I've always been lead to believe that stock springs were in the 90-100 lb range. I guess I'm guilty of propagating mythology. Anyone have an OEM stock spring to confirm free length? Super interesting information that I should have verified for myself long ago! |
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