914 Track Suspension, Torsion Bar & Springs |
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914 Track Suspension, Torsion Bar & Springs |
trapper |
Sep 22 2007, 10:02 PM
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#1
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Newbie Group: Members Posts: 37 Joined: 6-February 03 From: Brighton, MI Member No.: 258 |
I need some suspension advice! I bought a 914-6 track car last spring and it is very soft. I don't know what I have installed yet but I suspect I need an upgrade over the winter. The car is a 2.8 liter with full cage. Any recommendations as to torsion bar size and rear springs? The car has front and rear sway bars, Bilsteins and monoball
front mounts. (IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/smash.gif) |
J P Stein |
Nov 28 2007, 10:14 PM
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#2
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
The front end is lighter than the back,,,,,duh...
Less spring rate there, more in the back. My car has 700 lbs on the front tires & 1000lbs on the rears (rough numbers). So a 30% difference should be about right....disregarding the motion ratio for the moment. The idea is to get the rates close enough to be able to adjust your anti roll bar for both oversteer & understeer as desired......this means half hard at neutral. (I use a front AR bar only). There is more to consider, of course.(IMG:style_emoticons/default/biggrin.gif) I found I had to raise my rear rates to keep both rear tires firmly in contact with the ground at AX. With an LSD, lifting one (or just unloading it) will cause severe oversteer, with an open diff forward progress ceases. OK, we fixed that without too much problem, but had to stiffen the AR bar to take out some (but not all) of the oversteer. My spring rates aren't gonna tell you much as not many folks run as much tire as I do and it is an AX only car. It's too unstable to do much with on a track as it is set up. |
SirAndy |
Dec 1 2007, 07:59 PM
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#3
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Resident German Group: Admin Posts: 41,662 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
The front end is lighter than the back,,,,,duh... Less spring rate there, more in the back. My car has 700 lbs on the front tires & 1000lbs on the rears (rough numbers). So a 30% difference should be about right....disregarding the motion ratio for the moment. The idea is to get the rates close enough to be able to adjust your anti roll bar for both oversteer & understeer as desired......this means half hard at neutral. (I use a front AR bar only). There is more to consider, of course.(IMG:style_emoticons/default/biggrin.gif) I found I had to raise my rear rates to keep both rear tires firmly in contact with the ground at AX. With an LSD, lifting one (or just unloading it) will cause severe oversteer, with an open diff forward progress ceases. OK, we fixed that without too much problem, but had to stiffen the AR bar to take out some (but not all) of the oversteer. My spring rates aren't gonna tell you much as not many folks run as much tire as I do and it is an AX only car. It's too unstable to do much with on a track as it is set up. (IMG:style_emoticons/default/agree.gif) i'm back to the drawing board myself after dropping in the 3.6L. the added weight and additional "umpf" have changed the balance of the car, my old setup is not adequate anymore ... i'm leaning towards 22mm torsion bars and 350lbs springs ... (IMG:style_emoticons/default/bye1.gif) Andy |
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