PETEW Posted January 10, 2003 Share Posted January 10, 2003 I have been putting my suspension together and I have a problem. When I got my springs they came with no paper work, so we just matched them as best we could and went from there. I am putting the back suspension together and the springs are too short for the spring perch. The only markings I saw on the springs were a I and II. They all appeared to be the same length so we put the II up front (they looked beefier) and the I for the back. This was basically matching what was on it stock. What am I doing wrong? Am I supposed to be getting a shorter strut with this lowering suspension? Or do I have the springs reversed? I know alot of guys here have ST springs so I am hoping you can hep me. Please help I need to get this car together. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 11, 2003 Share Posted January 11, 2003 Look at wire diameter and number of coils to help you figure it out, if one looked beefier as you say that was probably the rear spring which is a stiffer rate than the front. Quote Link to comment Share on other sites More sharing options...
PETEW Posted January 11, 2003 Author Share Posted January 11, 2003 That is where I got really confused. When I took the stock springs off my car the fronts were thicker and had more coils. Everything that I have read on this board says that is incorrect. I'm not sure if it will make a difference, though, because the ST springs looked like they were the same length. I am so, so very confused. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 11, 2003 Share Posted January 11, 2003 More coils = lower spring rate, IF the same spring diameter, removing coils makes the spring have a higher rate. When I looked at stock specs of the springs in the Haynes, the rear springs have a thicker wire diameter, and I think maybe an inch longer but I've already forgotten, these are recent posts if you look at the other spring thread. Maybe even possible someone played with your springs before you bought the car, hmm. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 11, 2003 Share Posted January 11, 2003 The "other" spring thread: http://www.hybridz.org/ubb/ultimatebb.php?ubb=get_topic;f=6;t=001928 Calculate your spring rates: http://www.proshocks.com/calcs/coilsprate.html Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 11, 2003 Share Posted January 11, 2003 Originally posted by PETEW:STOCK (1977 280Z): Front Rear Length 15.75" 15.25" # coils 11 10 spring dia. .474 .474 Ok, so with one less active coil the rear springs are sliiiiiiiiiightly stiffer. Spring diameter that you posted is wire diameter, the spring median is also used to calculate rate, which is the OD of the spring assembly minus the wire diameter, which gives you center of wire to center of wire, make sense? Quote Link to comment Share on other sites More sharing options...
GAZRNR Posted January 12, 2003 Share Posted January 12, 2003 Mudge, I used Suspension Tech springs on my 78 - NOPI PN# 591+0845 60145. The springs were tagged for the fronts only. Neither the front or rears touched the perch out while of the car. Tech support said that was "OK" but it seemed all wrong to me so I used 7 or 8 washers to push the perch lower and put some tension on the spring while at full extension. If you have your struts out and dissasembled you can see the second shoulder that the washers will rest on. The stock replacement struts were not up to the task and had to upgrade the struts, I used Tokio Illumina stuts on all four corners to keep the car from bottoming out. I have to run the rears on setting 4 to keep the rear from bottoming out crossing bridges at normal highway speeds. I am really dissapointed with these springs and would have put the stock springs back in with a coil & 1/2 cut out if had not already tossed them out BEFORE I test drove the car. Lesson learened! When I get a chance I will install coil overs and then be able to tune my suspension. Good luck with making them work for you. Quote Link to comment Share on other sites More sharing options...
PETEW Posted January 12, 2003 Author Share Posted January 12, 2003 OK, here is where I am at. I went outside and measured the stock springs and did some measurements of the Suspension Techniques springs. I tried calling ST but it just rang and rang. Anyway, here are the results I found. STOCK (1977 280Z): Front Rear Length 15.75" 15.25" # coils 11 10 spring dia. .474 .474 I checked my Haynes manual and everything looks about right. They don't say anything about the spring dia. for the 280Z, though. Suspension Techniques: Front Rear Length 11.5" 11.5" # coils 9 8 spring dia. .504 .482 I can't be sure about the length of the front (of the ST spring) because it is mounted on the car. But my friend and I both remember them being equal length. We put the higher amount of coils on the front just like it was stock. The problem I have is the rears just don't touch the top spring perch when assembling them. I don't know if this will be an issue when mounted on the car but I would rather get the right info the do a trial by error method. I am also worried that if the car goes over a bump and unloads the suspension that the spring would move around in the perch. Talk about dangerous! Maybe the suspension doesn't have enough movement for this to be a problem, I'm not sure. Hopefully someone has some answers. Hopefully someone can help me out on this. I just want to get my car together so I can start on the motor. I'm starting to wish I got coil overs, but they just aren't in the budget right now. Thanks for your help guys. Quote Link to comment Share on other sites More sharing options...
Synlubes Posted January 12, 2003 Share Posted January 12, 2003 I`ll have to go with Mudge, Put the springs that have the thickest coil dia in the rear. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 12, 2003 Share Posted January 12, 2003 My 76 has the st springs and neither front or back spring touches the perch when off the ground. Tech support said that it was okey dokey. Can't help with the number or size of coils for placement. It's been 9 years since I did this to my car. Quote Link to comment Share on other sites More sharing options...
PETEW Posted January 12, 2003 Author Share Posted January 12, 2003 Thanks for all the help guys. I'm just going to keep it as is, and see what happens. I don't think my wire diameter #'s are truely correct there are too many factors that could affect the thickness (wire bending, powder coating, etc). I am going strictly by the # of coils more up front less out back (just like stock). I see GAZRNR and Jetdriver said that ST said it was ok to have the springs loose in the perch. I guess I will see. Funny though, my fronts are nice and tight in the perches just the back has slop. Oh well, thanks for the help. Quote Link to comment Share on other sites More sharing options...
Cable Posted November 18, 2009 Share Posted November 18, 2009 Digging up an old thread..... So what ever happened? How is the ride? Thanks!! Quote Link to comment Share on other sites More sharing options...
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