Posted March 21, 201113 yr comment_350114 While it's just temporary until I can afford a real suspension I'm trying cut springs and different spring options. Currently I'm running the normal 240z springs but I found a good set of 280z springs. Now I was told the 280z has a stiffer spring but it's a softer rate than the 240z, is that true? I was looking for a somewhat stiffer ride. I've looked around and haven't seen anything on this mostly 240z springs on 260's and 280's. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/ Share on other sites More sharing options...
March 21, 201113 yr comment_350115 I think you will have to cut the 280 springs. They ride higher than the 240 I think. They aren't stiff either. Softer than what you have I think. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350115 Share on other sites More sharing options...
March 21, 201113 yr comment_350121 280z springs on 240z should lower it, at least according to a grass roots z racer told me.I just took his word for it. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350121 Share on other sites More sharing options...
March 21, 201113 yr comment_350122 The 280Z springs are quite a bit stiffer - looks like you could cut a coil or 1 1/2 coils off.As I recall the 280Z's sit higher because they have a taller isolator at the top of the strut.<pre> 1977 280Z 240ZFRONTSpring Rate: 103 lb/in 83 lb/inFree Length: 15.98 in 15.2 inActive Coils: 9.5 8.5REARSpring Rate: 127.7 103 lb/inFree Length: 15.43 in 15.0 inActive Coils: 8.5 9.5</Pre>FWIW,Carl B. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350122 Share on other sites More sharing options...
March 21, 201113 yr comment_350139 Data I pulled from Zcar.com archives:0.5" drop = cutting upper and lower coil1.5" to 2" drop = cutting upper two coils or lower two coils (recommended)2" to 2.5" drop = cutting upper 2 coils and lower coil Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350139 Share on other sites More sharing options...
March 21, 201113 yr comment_350144 Its all about the isolater, I used a 280 isolator on my 73 when I changed the spring to even out the car. Factory rates are different but aftermaket are all the same except for the isolater. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350144 Share on other sites More sharing options...
March 21, 201113 yr comment_350152 Interesting. sorry for the incorrect info. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350152 Share on other sites More sharing options...
March 21, 201113 yr comment_350156 While it's just temporary until I can afford a real suspension I'm trying cut springs and different spring options. Currently I'm running the normal 240z springs but I found a good set of 280z springs. Now I was told the 280z has a stiffer spring but it's a softer rate than the 240z, is that true? I was looking for a somewhat stiffer ride. I've looked around and haven't seen anything on this mostly 240z springs on 260's and 280's.280z springs are stiffer than a 240'z, I used the rear insulators from a 240z on my 280z and cut 1.5 coils at the top of the stock springs. Rides lower and more aggressive now. Edited March 21, 201113 yr by johnnyt Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350156 Share on other sites More sharing options...
March 21, 201113 yr Author comment_350194 Thank you everyone for the information it really helps. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350194 Share on other sites More sharing options...
March 22, 201113 yr comment_350242 Its all about the isolater, I used a 280 isolator on my 73 when I changed the spring to even out the car. Factory rates are different but aftermaket are all the same except for the isolater.No, they are not. A little enlightenment is called for. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350242 Share on other sites More sharing options...
March 22, 201113 yr comment_350285 One thing to remember...quasi fictional example: If a Z weighs 2400lbs and is 50/50 weight distribution then you have 600 lbs of weight on each wheel. If a performance spring is rated 200lbs/ per inch and just fits in the strut without the need for a compressor then it will drop 3" (600lbs / 200lbs/inch) when loaded by the car. If you have a stock spring that is 100 lbs/per inch that needs to be compressed 6" to fit in the strut then the car will not drop because the 6" of compression preloads the strut to 600lbs. To properly pre-calculate drop you need: Corner weights Spring constant (lbs/inch) Length of uncompressed spring Length of spring in unloaded strut If I had time I would love to collect this data for stock springs. As mentioned above. Some of the 280z strut isolators are thicker and can lift the car slightly. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350285 Share on other sites More sharing options...
March 23, 201113 yr Author comment_350424 Wow those look like they could use a good cleaning. Link to comment https://www.classiczcars.com/forums/topic/38971-280z-springs-on-a-240z/#findComment-350424 Share on other sites More sharing options...
Create an account or sign in to comment