Need H&R Spring recommendation for 325in/lb coilovers - Ford Mustang Forums : Mustang Forum
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post #1 of 5 Old 03-13-2009, 10:24 PM Thread Starter
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Need H&R Spring recommendation for 325in/lb coilovers

Hey guys, I was wondering if anyone had an H&R rear spring recommendation for using 325 in/lb front coilover springs. The car is a street car, just looking to make it balanced. 82 Capri, weighs 3000lbs wet, no phb or torque arm... stock quadrabind.

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post #2 of 5 Old 03-14-2009, 12:45 PM
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According to Maximum Motorsports, there are no regular rear springs that will match a front coilover rate higher than 275-300 lbs. To get a high enough rear rate you need rear coilovers. That's what they told me anyway. I ended up using 275 lb front coilover and H&R rear super race springs on my 92 GT.

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post #3 of 5 Old 03-14-2009, 01:22 PM
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Well, if the "rule of thumb" that a few guys on this board have said MM uses (100lb difference between front and rear spring rates) for determining coil over spring rate is used, it would indicate using a 225# spring in the rear...but, as you don't have coil overs in the rear, you need to determine what type of spring rate, in the stock location, approximates the wheel rate that a 225# coil over provides. Using MM's motion ratios, the 225# coil over gives a 247.5 wheel rate (1.1 X 225). To get a wheel rate close to that with a stock location coil spring, with a motion ratio of .5, seems to indicate a 500lb spring, i.e. 250 wheel rate. That would just be a starting point, though, as a number of other variables are changed when going from the stock, LCA spring position to the axle...

I'm still at a loss to understand the "rule of thumb", though...

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post #4 of 5 Old 03-14-2009, 02:00 PM
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Really high rear spring rates might not be a good thing with the stock suspension.

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post #5 of 5 Old 03-18-2009, 08:01 AM
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I used H&R Race rear springs with 300 lb/in front coil-overs. I had asked at one point if I should step up to the super race springs, and it was advised to keep the race springs until I move to a torque arm. I don't have too much data to report on for handling with that set-up because the ball joint fell out of the control arm on the second run of the only autocross I ran last year.

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