Alan_Thomas
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| posted on 31/10/04 at 07:40 PM |
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Does this sound right?
My car was completed using an old set of coilovers from a westfield. They weren't up to much but they were very very cheap! I always promised
myslf a new set when the car was on the road.
Well, 1500 miles later, the front nearside gave out completely and now offers no damping. I have bought a new set of GAZ coilovers from Ebay but need
to buy new springs because the GAZ take larger diameter.
Happy with the ride of the old units I want the same spring rate. I have just measured it by jacking up one side of the car, placing the spring on the
bathroom scales under the car and slowly lowering the jack until I got 1" compression. (placed a bit of tube 1" shorter than free length
inside the coils to act as a guide) The reading was 240lbs. does that sound right for a locost with crossflow? I don't want to buy a set of
springs and find they are bottoming. - Alan
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stephen_gusterson
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| posted on 31/10/04 at 07:46 PM |
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there are formulas for calculating spring rates - someone on here should be able to give you them.
you would need a vernier to measure the wire dia.
atb
steve
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Dave Ashurst
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| posted on 31/10/04 at 08:20 PM |
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Sounds about right for the front springs, Alan.
The rear springs will probably be between 190lbs/inch?
Because they slope the front ones need to be stiffer than the vertical rear spings to give a similar effective vertical stiffness (if that's
what you want).
The damping will have a big effect too. IMO it's well worth spending some time to adjust your gaz shocks to suit the car and the spring
rate.
regards
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Stu16v
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| posted on 31/10/04 at 09:43 PM |
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 Ingenious, but necessarily accurate Alan, for the reason that Dave mentions. To keep it simple, as the spring is mounted at an angle, what you
read at the scales isnt going to be the spring poundage-it is likely to be higher than this. Another reason is that the spring may already be
'pre-loaded', i.e. when the shocker is at full length, the spring may already be under some compression.
It would be fairly accurate if you could do the same somehow, but with the spring acting directly onto the scales.
Otherwise, if you are lucky, if you look carefully at the top/bottom of the springs (the machined flat bits), you might just find the poundage etched
or painted on...
[Edited on 31/10/04 by Stu16v]
Dont just build it.....make it!
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Alan_Thomas
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| posted on 31/10/04 at 11:07 PM |
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quote:
Originally posted by Stu16v
:"It would be fairly accurate if you could do the same somehow, but with the spring acting directly onto the scales. "
Stu - Actually The spring was off the car and acting directly (vertically) on the scales. I was using the car just as a weight to compress the spring
- Alan
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MikeP
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| posted on 1/11/04 at 01:28 PM |
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Sounds right to me Alan, but scary as h*ll  .
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chrisf
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| posted on 1/11/04 at 06:42 PM |
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Try this one.
Pete Bura showed me this formula. I used it and think it is the most accurate way that I know to estimate coil rate.
Wheel Rate / [(Instant Center/Swing Axle Length)^2 (Chassis to damper pickup/Chassis to Ball Joint)^2 (COS Damper angle from vertical)^2] = Coil Rate
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barrie sharp
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| posted on 2/11/04 at 08:33 AM |
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190 rears 220 fronts on my crossflow
the cars looking good" a blind man would be pleased to see it"
''stop press'' the blind mans seen it said "it felt ok"
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