rear springs for sedan

Suspension, including wheel, tire and brake.
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68 Wagon
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rear springs for sedan

Post by 68 Wagon »

I've installed 83 280zx stuts with GC 200 lb coilovers in the front of my 72 VG30E 4 dr. Where do I get the appropriate rear springs for the stock location to match my front spring rate?
I've been driving 70's Datsun sedans, wagons, and roadsters almost every day since 1983!
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okayfine
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Re: rear springs for sedan

Post by okayfine »

Comp Roadster front springs with a closed coil cut will give something just over 200in/lb at the wheel. Otherwise you can look through the 5" OD springs for roundy-round racing and pick a rate and length that work.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Uber Deaf One
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Location: Santa Clara, CA

Re: rear springs for sedan

Post by Uber Deaf One »

I can get you 3.5" ID springs in any stiffness and any height you want/need.. PM me.

I'm currently running 9" tall 1140 lb springs which comes out to 296ish lbs wheelrate. In fact I have a set of these for sale if that's the spring rate you're interested in.
rocko
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Location: Cedar Rapids, IA

Re: rear springs for sedan

Post by rocko »

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Last edited by rocko on 23 Feb 2012 12:17, edited 1 time in total.
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okayfine
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Re: rear springs for sedan

Post by okayfine »

rocko wrote:and does it ride a little softer then stock
:shock: Stock rear wheel rate is ~90in/lb. Not sure how something over three times stiffer is going to give a softer ride...
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
rocko
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Re: rear springs for sedan

Post by rocko »

okayfine wrote:
rocko wrote:and does it ride a little softer then stock
:shock: Stock rear wheel rate is ~90in/lb. Not sure how something over three times stiffer is going to give a softer ride...
I am a big time n00b when it comes to calculating all this spring rate shit out...It just gives me a headache...sorry.
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okayfine
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Re: rear springs for sedan

Post by okayfine »

It doesn't help that you have to divide rear spring rate by 3.8 to determine wheel rate. This is due to the spring being located closer to the rear suspension pivot than the wheel. I know you were told there would be no math, but that was a lie. :)
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
rocko
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Re: rear springs for sedan

Post by rocko »

okayfine wrote:It doesn't help that you have to divide rear spring rate by 3.8 to determine wheel rate. This is due to the spring being located closer to the rear suspension pivot than the wheel. I know you were told there would be no math, but that was a lie. :)
sooo what your saying is if the spring rate is 415# example you divide that by 3.8=164# wheel rate. Now do you do the same thing with the stock numbers sooo...316#/3.8=83# wheel rate. So does that mean the 415# pound spring would be twice as stiff as the stock spring. And how do u modify the numbers for cutting the spring....so if you buy that 415# spring and its 11" tall how will cutting 2" out of it affect the spring rate in #s
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okayfine
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Re: rear springs for sedan

Post by okayfine »

I'll leave most of that alone unless you don't like the advice in your other thread. Essentially (ignoring the closed coil ends) if you have a spring that's got 10 coils and is 100in/lb spring, you cut 1 coil you increase the rate by 10%.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Uber Deaf One
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Re: rear springs for sedan

Post by Uber Deaf One »

415/3.8 is 109 lbs.. not quite 2x stiffer than stock. Only about 20 lbs (at the wheels) stiffer than stock.

If you want to determine how much stiffer you're making a spring when you cut it... there's a whole bunch of math involved in that one. That all depends on how many coils there are, how thick the spring itself is, etc. etc. If you do some research on Google you can figure all that out pretty easy.
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